Bosh Motronic ME 7.1.1
Bosh Motronic ME 7.1.1
.04.01.00 LEAKAGE CHECK ........................................................................................................................................17 .04.01.01 General description................................................................................................................................17 .04.01.02 Monitoring function description ............................................................................................................17 .04.01.03 Chart(s) and flow chart(s)......................................................................................................................18 .04.02.00 PURGE CHECK .............................................................................................................................................20 .04.02.01 General description................................................................................................................................20 .04.02,02 Monitoring function description ............................................................................................................21 .04.02.03 Chart(s) and flow chart(s)......................................................................................................................21 .05.00.00 SECONDARY AIR SYSTEM MONITORING.........................................................................................22
.05.01.00 VIA LAMBDA DEVIATION .............................................................................................................................22 .05.01.01 General Description...............................................................................................................................22 .05.01.02 Monitoring Structure..............................................................................................................................23 .05.01.03 Chart(s) and flow chart(s)......................................................................................................................25 .05.02.00 VIA EXHAUST TEMPERATURE SENSOR .........................................................................................................27 .05.02.01 General Description...............................................................................................................................27 .05.02.02 Monitor function description .................................................................................................................27 .05.02.03 Chart(s) and flow chart(s)......................................................................................................................28 .06.00.00 Fuel System Monitoring ...............................................................................................................................29 General Description...............................................................................................................................29 Monitoring function description ............................................................................................................29 Chart(s) and flow chart(s)......................................................................................................................30 OXYGEN SENSOR MONITORING .......................................................................................................33
.07.01.00 CALIBRATIONS WITH ASIC CJ 110 .............................................................................................................33 .07.01.01 General Description...............................................................................................................................33 .07.01.02 Monitoring function description ............................................................................................................33 .07.01.03 Chart(s) and flow chart(s)......................................................................................................................35 .07.02.00 OXYGEN SENSOR HEATER MONITORING .....................................................................................................40 .07.03.01 General description (ASIC CJ 110) .......................................................................................................40 .07.02.02 Monitor function description .................................................................................................................40 07.02.03 Chart(s) and Flow Chart(s) ...................................................................................................................41 .07.03.01 General Description...............................................................................................................................43 .07.03.02 Monitor function description .................................................................................................................43 .07.03.03 Chart(s) and Flow Chart(s) ...................................................................................................................45 .07.04.00 OXYGEN SENSOR HEATER MONITORING (ASIC CJ 125/120) .....................................................................47 .07.04.01 General description................................................................................................................................47 .07.04.02 Monitor function description .................................................................................................................47 .07.04.03 Chart(s) and Flow Chart(s) ...................................................................................................................48 .07.05.00 SULEV APPLICATIONS ...............................................................................................................................49
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COLD START EMISSION REDUCTION STRATEGY MONITORING............................................73 AIR CONDITIONING (A/C) SYSTEM COMPONENT MONITORING .............................................73 VARIABLE VALVE TIMING AND/OR CONTROL (VVT) SYSTEM MONITORING ....................73 DIRECT OZON REDUCTION (DOR) SYSTEM MONITORING ........................................................73 PARTICULATE MATER (PM) TRAP MONITORING .........................................................................73 COMPREHENSIVE COMPONENTS MONITORING...........................................................................73 INJECTION VALVE .......................................................................................................................................73 FUEL PUMP RELAY ......................................................................................................................................73 IDLE CONTROLLER ......................................................................................................................................74 ENGINE SPEED SENSOR: ..............................................................................................................................75 WARM-UP BYPASS VALVE:..........................................................................................................................75 SIGNAL RANGE CHECK FOR DIFFERENT SENSOR ..........................................................................................76 RATIONALITY MASS AIR FLOW SENSOR (MAF) .........................................................................................77 VEHICLE SPEED SENSOR (VSS)...................................................................................................................79 THROTTLE POSITION SENSOR (THROTTLE UNIT WITH E-GAS ACTUATOR) ...................................................80 ACCELERATOR PEDAL POSITION SENSOR (APPS) ........................................................................................81 CAMSHAFT POSITION SENSOR .....................................................................................................................82 BOOST PRESSURE CONTROL VALVE ............................................................................................................83 ENGINE START DELAY RELAY (SULEV) ....................................................................................................84 EXHAUST TEMPERATURE SENSOR (SULEV)...............................................................................................85 General Monitoring Description ...........................................................................................................85 Monitor function description .................................................................................................................85 Chart(s) and Flow Chart (s) ..................................................................................................................86 RESERVED ...................................................................................................................................................87 RESERVED ...................................................................................................................................................87 RESERVED ...................................................................................................................................................87 RESERVED ...................................................................................................................................................87 RESERVED ...................................................................................................................................................87 AUTOMATIC TRANSMISSION MONITOR .......................................................................................................88 OUTPUT STAGE CHECK ...............................................................................................................................88
.16.01.00 .16.02.00 .16.03.00 .16.04.00 .16.05.00 .16.06.00 .16.07.00 .16.08.00 .16.09.00 .16.10.00 .16.11.00 .16.12.00 .16.13.00 .16.14.00 .16.14.01 .16.14.02 .16.14.03 .16.15.00 .16.16.00 .16.17.00 .16.18.00 .16.19.00 .16.20.00 .16.21.00 .17.00.00 .18.00.00 .19.00.00 .20.00.00
OTHER EMISSION CONTROL OR SOURCE SYSTEM MONITORING .........................................89 EXEMPTIONS TO MONITOR REQUIREMENTS ..............................................................................89 RESERVED...................................................................................................................................................89 PARAMETERS AND CONDITIONS FOR CLOSED LOOP OPERATION........................................90
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.01.00.00
CATALYST MONITORING There are two diagnostic functions, which are used for monitoring of the catalyst efficiency. Both are based on measure of the Oxygen within the catalyst determined by at least two Oxygen sensors. Each of the functions can be correlated between Oxygen / Hydrocarbon and Oxygen/ Oxides of Nitrogen.
.01.01.00 .01.01.01
Passive measurement of amplitude ratio General description The method compares the signal amplitudes obtained from the downstream sensor to the modelled signal amplitudes. The modelled signal amplitudes are derived from a borderline catalyst. The data for borderline catalysts are taken from measurement results on real life deteriorated catalysts. In case the measured amplitudes exceed those of the model, the catalyst is considered defective. This information is evaluated within one single engine load and speed range (detection over full range of engine load versus speed). According to the described operating principle the following main parts can be distinguished: Computation of the amplitude of the downstream oxygen sensor: The amplitude of the signal oscillations of oxygen sensor downstream catalyst is calculated. Extracting the oscillating signal component, computing the absolute value and averaging over time accomplish this. Modelling of a borderline catalyst and of the signal amplitudes of the downstream oxygen sensor: The model is simulating the oxygen storage capability of a borderline catalyst. The signal of the downstream oxygen sensor is simulated in the catalyst model based on real time engine operating data (e.g. A/F ratio and engine load). The amplitude of the modelled signal oscillations is calculated. Signal and fault evaluation The signal amplitudes of the downstream oxygen sensor are compared with the model for a given time. In case of the signal amplitudes of the downstream sensor exceed the modelled amplitudes, the oxygen storage capability of the catalyst falls short of the borderline catalyst model. Check of monitoring conditions It is necessary to check the driving conditions for exceptions where no regular Lambda control is possible, e.g. fuel cut-off. During these exceptions, and for a certain time afterwards, the computation of the amplitude values and the post processing is halted. Thus, a distortion of the monitoring information is avoided.
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.01.01.02
Monitoring Structure The catalyst temperature (model) activates the catalyst monitoring function if the catalyst temperature is above a predetermined value.
.01.01.03
Start
no
Enable? Models stabilized? yes Calculate: - catalyst model - modeled sensor - downstream sensor
yes
Catalyst deteriorated
no Catalyst okay
Fault management
MIL End
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Bosch Motronic ME 7, ME 7.1, ME 7.1.1, ME 7.5 System Strategy .01.02.00 .01.02.01 Active measurement of OSC General description The catalyst monitor is based on the determination of oxygen storage capability (OSC). The correlation between conversion efficiency and the OSC has been investigated on catalysts with various characteristics specifically concerning stages of aging correlated to exhaust emissions (HC/NOx). Therefore, the catalyst is diagnosed by comparing its storage capability against the storage capability of a borderline catalyst. The oxygen storage capability (OSC) can be determined by one of the following two methods: 1. Oxygen reduction after fuel-cut (Quick pass of the monitor) Oxygen is stored in the catalyst during fuel-cut conditions happening while driving the vehicle. After fuel-cut, the catalyst is operated with a rich air-fuel ratio (A/F) and the amount of removed oxygen is determined. If this passive test indicates an OSC value highly above the borderline catalyst, the catalyst is diagnosed without an error. This monitoring path can only generate a pass result. 2. Determination of Oxygen storage (active test) For purposes of monitoring, the ECM cycles the A/F ratio by commanding a rich and a lean fuel mixture as follows. First, ECM commands a rich A/F ratio until a minimum of oxygen has been removed (cumulated rich gas > threshold). Then, the catalyst is operated with a lean A/F ratio commanded by ECM and the Oxygen Storage Capability is calculated from the oxygen mass stored in the catalyst as follows: OSC = air mass flow * lean mixture (-1) * dt The catalyst is operated in this mode until the oxygen stored in the catalyst exceeds a calibrated limit or the downstream oxygen sensor indicates that the catalyst is completely saturated with oxygen. The catalyst is then diagnosed by comparing its oxygen storage capability to the calibrated threshold of a borderline catalyst.
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.01.02.02
Monitoring Structure According to the operating principle described above the following main parts of the monitor can be distinguished: Monitoring the amount of removed oxygen after fuel cut off Check of monitoring conditions for active test Lambda request (interface to lambda controller) Mixture enrichment in order to remove any stored oxygen Measurement of oxygen storage capacity (OSC) by lean A/F ratio operation Processing Fault detection
Check Monitoring Conditions Mixture Enrichment (remove oxygen ) mixture control L Lambda Request
Measurement of OSC (lean A/F ratio) fail Oxygen Removal after fuel cut off Processing Fault Detection pass
Processing: After the measurement of the OSC, the OSC-value is normalized to the OSC-value of the borderline catalyst, which is taken from a map, depending on exhaust gas mass flow and catalyst temperature. The final diagnostic result is calculated by averaging several, normalized OSC-values and compared to the threshold. The measurement of OSC can be carried out consecutive or stepwise.
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For a catalyst system with 3 Oxygen-Sensors this measuring procedure can be applied to different portions. The different alternatives are shown in the table below. first -sensor front- catalyst second -sensor main- catalyst
catalyst-system Table 1: Necessary conditions to check the different catalyst volume Secondary parameters First -sensor is active Second -sensor is active Modelled exhaust gas temp. in range First -sensor is active Second -sensor is active Third -sensor is active Modelled exhaust gas temp. In range First -sensor is active Second -sensor is active Third -sensor is active Modelled exhaust gas temp. In range First -sensor is active Second -sensor is active Modelled front exhaust gas temp. In range Modelled main exhaust gas temp. In range Exhaust- gas mass flow in range Exhaust- gas mass dynamic in range First -sensor is active Second -sensor is active Third -sensor is active Modelled front exhaust gas temp. In range Modelled main exhaust gas temp. In range Exhaust- gas mass flow in range Exhaust- gas mass dynamic in range First -sensor is active Third -sensor is active Modelled front exhaust gas temp. In range Modelled main exhaust gas temp. In range Exhaust- gas mass flow in range Exhaust- gas mass dynamic in range Frontcatalyst Quick pass Maincatalyst Catalystsystem
Quick pass
{Quick pass
Quick pass}
=> Quick
pass
Measureme nt of OSCcalculation
Measureme nt of OSCcalculation
Measurement of OSCcalculation
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If the secondary parameters for the different catalyst portions are met at the same time, the diagnostic functions can run simultaneously. According to table 1 the following result combinations are described in table 2. Table 2: Results, which can be obtained after the diagnosis of the different catalyst volumes
Front catalyst
Result
Quick pass Quick pass Quick pass Measurement of OSCcalculation < threshold Measurement of OSCcalculation > threshold Measurement of OSCcalculation < threshold Measurement of OSCcalculation > threshold Measurement of OSCcalculation > threshold Measurement of OSCcalculation < threshold
Both = pass front catalyst = pass main catalyst = Fail Both = pass front catalyst = Fail main catalyst = passe Both = pass Both = fail Both = pass front catalyst = pass main catalyst = fail front catalyst = fail main catalyst = pass
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.01.02.03
fuel cut off ? Yes No catalyst temperature in range ? Yes calculate amount of oxygen after fuel cut off
No
apply rich mixture to catalyst (oxygen removal) accumulate amount of applied rich mixture
No
apply lean mixture to catalyst (oxygen storing) accumulate amount of oxygen stored in
osc > calibration or catalyst saturated ? Yes number of measurements > threshold ? Yes mean - value calculation
No
No
NO pass
Yes fail
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Bosch Motronic ME 7, ME 7.1, ME 7.1.1, ME 7.5 System Strategy .02.00.00 HEATED CATALYST MONITORING Not applicable .03.00.00 MISFIRE MONITORING
.03.00.01
General Description The method of engine misfire detection is based on evaluating the engine speed fluctuations. In order to detect misfiring at any cylinder, the torque of each cylinder is evaluated by metering the time between two ignition events, which is a measure for the mean value of the speed of this angular segment. This means, a change of the engine torque results in a change of the engine speed. Additionally the influence of the load torque will be determined. When the mean engine speed has been measured, influences caused by different road surfaces have to be eliminated (e.g. pavement, pot holes etc.). This method consists of the following main parts: Correction of normal changes of engine rpm and engine load
Data acquisition, adaptation of sensor wheel and typical engine behaviour is included Calculation of engine roughness Comparison with a threshold depending on operating point Fault processing, counting procedure of single or multiple misfire events
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.03.01.02
Monitoring function description Data acquisition The duration of the crankshaft segments is measured continuously for every combustion cycle and stored in a memory. Sensor wheel adaptation Within defined engine speed and load ranges the adaptation of the sensor wheel tolerances and the typical engine behaviour is carried out, if no misfire events are detected. With progressing adaptation the sensitivity of the misfire detection is increasing. The adaptation values are stored in a non-volatile memory and taken into consideration for the calculation of the engine roughness. Misfire detection The following operating steps are performed for each measured segment, corrected by the sensor wheel adaptation.
Calculation of the engine roughness The engine roughness is derived from the differences of the segment's duration. Different statistical methods are used to distinguish between normal changes of the segment duration and the changes due to misfiring. Detecting of multiple misfiring If several cylinders are misfiring (e.g. alternating one combustion/one misfire event), the calculated engine roughness values may be so low, that the threshold is not exceeded during misfiring and therefore, misfiring would not be detected. Based on this fact, the periodicity of the engine roughness value is used as additional information during multiple misfiring. The engine roughness values are filtered and a new multiple filter value is created. If this filter value increases due to multiple misfiring, the roughness threshold is decreased. By applying this strategy, multiple misfiring is detected reliably. Calculation of the engine roughness threshold value The engine roughness threshold value consists of the base value, which is determined by a load/speed dependent map. During warm-up, a coolant-temperature-dependent correction value is added. In case of multiple misfiring the threshold is reduced by an adjustable factor. Without sufficient sensor wheel adaptation the engine roughness threshold is limited to a speed dependent minimum value. A change of the threshold towards a smaller value is limited by a variation of filter value (low pass filter).
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Determination of misfiring Random misfire Comparing the engine roughness threshold value with the engine roughness value performs misfire detection. If the engine roughness value is greater than the roughness threshold value a single misfire is detected. With this misfire determination it is possible to identify misfiring cylinders individually. Random misfire without valid adaptation To eliminate the influence of the missing flywheel adaptation each engine roughness value is compared with that one on the same flywheel segment on the intermittent revolution. Therefore single misfire events are detected reliable without determination of the flywheel tolerances. Continuous misfire on one or multiple cylinders To avoid noise effects, all engine roughness values are low pass filtered and the detection threshold is corrected by the mean value of the filters. Therefore the amplitude to noise ratio improves and the sensitivity for misfire detection of continuous misfiring cylinders increases.
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Statistics, Fault processing: Within an interval of 1,000 crankshaft revolutions, the detected number of misfiring events is totalled for each cylinder. If the sum of cylinder fault counters exceeds a predetermined value, a fault code for emission relevant misfiring is preliminary stored after completion of the first interval after engine has been started or the forth interval during a driving cycle where misfire has been detected. In the case of misfire detection for one cylinder, the fault is determined by a cylinder selective fault code otherwise the fault code for multiple misfire will be stored additionally. Within an interval of 200 crankshaft revolutions, the detected numbers of misfire events is weighted and totalled for each cylinder. The weighting factor is determined by a load/speed dependent map. If the sum of cylinder fault counters exceeds a predetermined value, the fault code for indicating catalyst damage relevant misfiring is stored and the MIL is illuminated with "on/off"-sequence once per second (blinking). In case of misfire detection for one cylinder the fault is determined by a cylinder selective fault code otherwise the fault code for multiple misfiring will be stored additionally. If catalyst damaging misfire does not occur any longer during the first driving cycle, the MIL will return to the previous status of activation (e.g. MIL off) and will remain illuminated continuously during all subsequent driving cycles if catalyst related misfire is detected again. However all misfire events where the catalyst can be damaged are indicated by a blinking MIL. If catalyst damage is not detected under similar conditions in the subsequent driving cycle the temporary fault code will be deleted. In the case of catalyst related misfire, the Lambda closed loop system is switched to open-loop condition according to the basic air/fuel ratio calculation (Lambda=1). All misfire counters are reset after each interval.
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.03.00.03
yes
no MIL
yes
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yes
no
no
yes
Misfire event?
no
no
Misfire event?
yes
yes
no
no
Sum of fault counters B1..Bn exceeds misfire frequency for catalyst damage?
yes
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The leakage diagnosis procedure is a pressure check of the EVAP system. In order to perform the check, the EVAP system will be sealed and pressure applied by the leakage diagnosis pump (LDP). The pressure variation time is analysed by the ECM. .04.01.02 Monitoring function description The diagnosis procedure consists of the following steps: 1. Tank pressure check The first step of leakage diagnostics is the pressure check of fuel tank system by testing the reed switch. In case of an open reed switch, the fuel tank system has sufficient pressure for the sealed check and no further pressure has to be supplied to the fuel tank system by the LDP. The diagnosis is waiting until the EVAP purge valve is opened in order to purge the carbon canister. In case the reed switch remains open or the reed switch stuck open, the reed switch is defective. In the case the reed switch is closed, the LDP is switched on in order to supply pressure to the fuel tank system and the diagnostic is continued with the step 2 to 3 (as described below). 2. LDP Self-check procedure Closed check LDP control is disabled and the reed switch has to be closed otherwise the reed switch is defective. Close to open check LDP control is switched on once and the diaphragm has to move to the upper position. The time is measured between closed and open position of diaphragm detected by the reed switch. When the final upper position of diaphragm is reached in a certain time, then the check will be passed. 3. Leak check of EVAP system Fast pulse After the self check procedure, the LDP control supplies pressure the fuel tank system with a pressure dependent number compression strokes in a certain time. In order to supply pressure the fuel tank system, the LDP can perform compression strokes several attempts.
to of to in
EVAP system sealed check, measure stroke and measure phase The decrease of fuel tank pressure is measured via time of diaphragm movement followed by a compression stroke. Within a certain time, the LDP control is determined within at least four measurement strokes. The averaged time is a measure for the tightness of fuel tank system.
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.04.01.03
yes
yes
pressure in fuel tank system detected, therefore EVAP leak check and purge check passed
valve OK, leak detection pump OK, system OK reed switch defective!
no
yes
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LDP switched on once folowed by a measure phase where time is measured until reed switch is closed again. The open to close time is measured at least four times and a an average is calculated.
yes
no
no
yes
yes
no
no
yes
yes
no
no
yes
fault management
MIL
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Bosch Motronic ME 7, ME 7.1, ME 7.1.1, ME 7.5 System Strategy .04.02.00 .04.02.01 Purge Check General description The purge flow through the EVAP Purge Valve is checked when the vehicle is at rest during an idle condition and the Lambda controller is active. The EVAP Purge Valve is opened while monitoring the Lambda controller and the airflow through the throttle unit. For rich or lean mixture through the EVAP Purge Valve: Flow through the EVAP Purge Valve is assumed as soon as the Lambda controller compensates for a rich or lean shift. After this procedure the EVAP Purge Valve is reset and the diagnosis is completed.
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.04.02,02
Monitoring function description For stoichiometric mixture flow through the EVAP Purge Valve: In this case, the Lambda controller does not need to compensate for a deviation. However, when the EVAP Purge Valve is completely opened, the cylinder charge increases significantly. Therefore, flow through the throttle unit must be decreased in order to maintain the desired idle speed. Flow through the EVAP Purge Valve is assumed when the flow through the throttle unit is reduced by idle control. If both mixture compensation and reduction of the airflow through the throttle unit does not occur for two diagnosis cycles, then a defective EVAP Purge Valve is assumed and the MIL is illuminated.
.04.02.03
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.05.00.00
.05.01.00 .05.01.01
Via lambda deviation General Description After cold start condition (e.g. 5 .. 40C) the Air system blows for a certain time air into the exhaust manifold. The exhaust gases will be enriched with oxygen and post combustion of HC and CO occurs. By this exothermic reaction the exhaust system will be heated and the time to reach the lightoff temperature of the catalyst will be accelerated. Principal sketch and main components of Air System: (example 4 cyl. Engine) ECM; Air pump relay Air valve (solenoid valve) Air valve (vacuum controlled) AIR pump; O2 Sensor;
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.05.01.02
Monitoring Structure
The following table shows an overview of the used function and monitor strategy for all test groups:
Test Group Engine Standard Via Lambda deviation Passive check Functi onal 5ADXV01.8342 5ADXV01.8356 5ADXV01.8346 5VWXV02.0223 5VWXV02.0224 5VWXV02.0227 5VWXV02.0240 5ADXV02.8334 5ADXV03.0344 5ADXV04.2345 5ADXT04.2348 5ADXV02.7343 5VWXT03.2225 5VWXV02.8228 5VWXV03.2220 5VWXV04.0229 5VWXV06.0221 5VWXV06.0501 1.8T I-4 Turbo long. 1.8T I-4 Turbo 1.8T I-4 Turbo 2.0l I-4 2.0l I-4 2.0l I-4 2.0l I-4 Turbo 2.8l V6 - 2 bank 3.0l V6 - 2 bank 4.2l V8 - 2 bank 4.2l V8 - 2 bank 2.7l V6T - 2 bank 3.2 VR6 - 2 bank 2.8 VR6 - 2 bank 3.2 VR6 - 2 bank 4.0l W8 2 bank 6.0l W12 2 bank 6.0l W12T 2 bank Bin 8 Bin 8 LEV I LEV II ULEV II PZEV ULEV II LEV I LEV II LEV I Bin 10 LEV I LEV II LEV I LEV I LEV I LEV I LEV I yes yes yes yes yes te Flow Check Active check Functi onal Yes yes yes Yes Yes yes Yes yes yes yes yes yes Yes Yes Yes Yes Yes Yes Flow Check yes Via exhaust temperature sensor Passive check Functi onal yes Flow Check Active check Functi onal Flow Check -
The monitor of the secondary air system distinguish between two functions: a) Passive monitoring function will be carried out during normal secondary air injection While engine is cold started and b) Active monitoring function will be activated later during the driving cycle, if the passive Monitoring function has not a pass result. At idle state or under part load engine condition, the secondary air pump is switched on and the valve opens either by pressure of the pump or vacuum operated by switching to open, causing an increase in the air fuel ratio. The Oxygen Sensor control function (closed loop) enriches the mixture consisting of exhaust gas of the engine and secondary air until the Lambda integrator signal will meet a predetermined value (functional or flow check).
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Check Conditions Passive Monitoring Function To start the passive monitoring function, following conditions have to be satisfied: Oxygen sensor readiness No engine restart (thermal energy introduced) A certain time after engine start Engine has been cold started No output stage error from secondary air pump relay
Active Monitoring Function To start the active monitoring function several conditions have to be satisfied: No result or no pass result from passive monitoring function available. Engine running at idle Closed loop condition of the Lambda-control Monitoring function not done before (for pump protection) No output stage error from secondary air pump relay Furthermore, if the diagnosis has already been started and one of the conditions has not been satisfied continuously, the process will be interrupted. The following conditions have to be fulfilled additionally: All adaptations of the air/fuel system are inhibited The Lambda controller has been stabilized (waiting for several transients of the oxygen sensor signal) The actual Lambda controller value has been stored In case of an interrupt of diagnosis, the monitor can several time started again (different for each test group; see overview) during the same driving cycle if the monitor conditions are met.
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.05.01.03
Following charts shows the phases of the AIR monitoring via lambda deviation for passive and active monitoring.
phase 1
phase 2 (optional)
phase 3
kg
kg
Lambda
=1
optional t1 t2
t3
Air Pump
time
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START
Adaptation inhibited Start integration of air mass flow PHASE 0 no Timer 0 > t 0 yes start SAI mass flow
PHASE 1
calculate actual AIR mass flow with actual Lambda value no timer 2 > t 2 ? yes -switch off AIR pump -start timer 3 for offset check
calculation of AIR mass offset at Lambda=1 (closed loop) no timer 3 > t 3 ? yes offset correction of actual AIR mass value
PHASE 3
calculation of relation between corrected actual and the nominal AIR mass flow
no
Fault management
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Bosch Motronic ME 7, ME 7.1, ME 7.1.1, ME 7.5 System Strategy .05.02.00 .05.02.01 Via exhaust temperature sensor General Description After cold start condition (e.g. 5 .. 40C) the Air system blows for a certain time air into the exhaust manifold. The exhaust gases will be enriched with oxygen and post combustion of HC and CO occurs. By this exothermic reaction the exhaust system will be heated and the time to reach the lightoff temperature of the catalyst will be accelerated. Additional to the principal sketch above, those systems using an exhaust temperature sensor as an indicator of AIR mass. .05.02.02 Monitor function description Passive monitoring function During normal secondary air injection the secondary air is indirect monitored via exhaust temperature using an exhaust temperature sensor. The measured exhaust temperature will be compared with modeled target temperatures contained in a map within ECM. After the secondary air injection ECM is calculating the amount of introduced thermal energy additionally. As long as the temperature sensor shows an increase in exhaust gas temperature and the thermal energy introduced (calculated by air mass times injected fuel), the secondary system will pass the monitor. No further active diagnostic will be performed. If one of the expected conditions fails, e.g. the temperature sensor is not showing an increase of temperature or the thermal energy introduction is below an expected threshold, the active monitoring function will be carried out later in that driving cycle.
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.05.02.03
no
no
yes
no
yes
no
yes
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.06.00.00 .06.00.01
Fuel System Monitoring General Description Mixture Pilot Control The airflow sucked in by the engine and the engine speed is measured. These signals are used to calculate an injection signal. This mixture pilot control follows fast load and speed changes. Lambda-controller The ECM compares the Oxygen sensor signal upstream the catalyst with a reference value and calculates a correction factor for the pilot control.
.06.00.02
Monitoring function description Adaptive pilot control Drifts and faults in sensors and actuators of the fuel delivery system as well as unmeasured air leakage influence the pilot control. The controller corrects amplitudes increases. If there are different correction values needed in different load speed ranges, a certain time passes until the correction is complete. The correction values will be determined in three different ranges. Fuel trim The basic air/fuel ratio control using the signal from the front O2 sensors(s) is corrected by an adaptation calculation. This adaptation results in a factor, which is applicable for the whole working range. (e.g. 20%) A further trim control based on the signal(s) from the rear O2 sensor(s) is correcting the adaptation factor. Therefore this trim control is working in the same way in the whole range. If the trim control reaches the allowed limit (e.g. 2%) the fault code for fuel delivery trim control is set. Any deviation from the characteristic curve of oxygen sensor upstream catalyst due to poison will be detected by the control loop downstream catalyst.
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.06.00.03
Injection quantity
Range 3
Range 2
Range 1
Engine speed
Lambda deviations in range 1 are compensated by an additive correction value multiplied by an engine speed term. This creates an additive correction per time unit. Lambda deviations in range 2 are compensated by multiplication of a factor. Lambda deviations in range 3 are compensated by multiplication of a factor (optional depending on individual calibration). A combination of all two (three) ranges will be correctly separated and compensated. Each value is adapted in its corresponding range only. But each adaptive value corrects the pilot control within the whole load/speed range by using a linear interpolation formula. The stored adaptive values are included in the calculation of the pilot control just before the closed loop control is active. Diagnosis of the fuel delivery system Faults in the fuel delivery system can occur which cannot be compensated for by the adaptive pilot control. In this case, the adaptive values exceed a predetermined range. If the adaptive values exceed their plausible ranges, then the MIL is illuminated and the fault is stored.
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Start Learning:: ACV = additive correction value rang 1 LMCV = lower multiplicative correction value range 2 UMCV = upper multiplicative correction value range 3 MLCC= multip. learning correction coefficient range 2 yes ACV, LMCV UMCV, MLCC remained unchanged no
Wait until ACV,LMCV, UMCV, MLCC have been activated for a certain time Set cycle flag for correction values
Lower threshold of MLCC<= LMCV <= upper threshold of MLCC yes UMCVmin <= UMCV <= UMCVmax yes ACVmin <= ACV <= ACVmax yes End
no
no Fault management
no
MIL
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no
yes
start counter t1
stop counter t1
no
yes
no
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Bosch Motronic ME 7, ME 7.1, ME 7.1.1, ME 7.5 System Strategy .07.00.00 .07.01.00 .07.01.01 OXYGEN SENSOR MONITORING Calibrations with ASIC CJ 110 General Description The Lambda control consists of a linear Oxygen sensor upstream catalyst and a 2-point oxygen sensor downstream catalyst. .07.01.02 Monitoring function description The sensors are monitored by several single monitoring procedures under the following basic conditions. - Engine operates in a specific range of speed/load map and - Modelled catalyst temperature is above a specific value
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The following checks will be performed on the linear oxygen sensor upstream catalyst: Heater Coupling Check (P0130) This monitoring will detect any short circuits between sensor heater and the Nernst cell of the Oxygen sensor by monitor the Lambda signal. The amplitude signal of Lambda is untypical and changed in the same velocity than heater duty cycle. Response Check (P0133) Any change in the dynamic behaviour of the Oxygen sensor due to ageing, heater fault or contamination will be detected by check of actual amplitude ratio check with stored values. Signal activity and rationality checks (P0130) The Lambda value of oxygen sensor upstream catalyst is compared to the sensor voltage downstream catalyst. Additionally, a check is performed by checking the sensor voltage range. Three diagnostics paths cover the air fuel ratio range of Lambda value (e.g. Lambda=1, lean, rich). A corresponding reaction of sensor voltage downstream catalyst is expected. (See chart) The following checks will be performed on the oxygen sensor downstream catalyst: Oscillation Check (P0139) The function checks whether the sensor output voltage of oxygen sensor downstream catalyst always remains above or below a specified threshold. Fuel cut off Check (P0139) During coasting, the ECM is monitoring the downstream sensor voltage, which has to go under a specific lean threshold. Output voltage (P0137), Short to battery (P0138) and signal activity check (P0140) In case the rear O2 sensor readiness is given a certain sensor signal is expected. If the sensor is bellow or above some signal thresholds, a fault will be stored.
- 34 -
.07.01.03
Front O2 Sensor
to 4.8 V lean rich
Rear O2 Sensor
= 1,005 =1 = 0,995
rich
0.0 V
lean
0.0 V
Based on the sensor comparison malfunction will be detected if: - Front sensor near lambda = 1 and rear sensor shows >0.7V or < 0,3 V - Front sensor lean (lambda > 1.05) and rear sensor rich (>0.7V) - Front sensor rich (lambda > 1.05) and rear sensor lean (<0.3V) - Rear sensor is not oscillation at reference point (e.g.0.6V) - During fuel cut off rear sensor signal goes not under threshold (e.g. 0.2V)
- 35 -
no
abs(L1-L2)> threshold 1
no
yes
no
start counter t1
no t1> threshold 4
yes
- 36 -
no
closed loop?
yes
no
no
Within engine load window? yes artificial modulation active? yes read actual amplitude
no
Calculate and filter ratio of target and actual amplitude. Calculate the sensor dynamic value.
no
- 37 -
Bosch Motronic ME 7, ME 7.1, ME 7.1.1, ME 7.5 System Strategy Rear O2 Sensor Oscillation check
DTCs Threshold 1 and 2 Limit P0139 Malfunction Criteria; typical values: 0.58 .. 0.6V Monitor time length 30 amplitudes
no
yes
no no fault stored ?
yes
no
yes
no
yes
yes
MIL
- 38 -
no wait for next fuel cut off condition (coasting) fuel cut off condition active?
yes
no
yes
- 39 -
.07.02.00 .07.03.01
Oxygen Sensor Heater Monitoring General description (ASIC CJ 110) For proper function of the Lambda sensor, the sensor element must be heated. Monitor function description Linear Oxygen sensor upstream catalyst Any fault in regard to sensor heater will either result in a lost or in a delay of sensor readiness. The diagnosis measures the time between the heater is switched on and the oxygen sensor readiness. The sensor readiness is indicated by a corresponding sensor voltage variation. Oxygen sensor downstream catalyst (2 point sensor) For diagnostic of the sensor heater a specific current pulse is supplied via a load resistance and the voltage is measured. The intern resistance of the sensor heater is calculated with the voltage deviation. The result will be compared with a reference map resistance, which considers ageing and sampling deviations. In case of internal resistance > map resistance the diagnosis stores a fault and the MIL will be illuminated.
.07.02.02
- 40 -
07.02.03
no
no
no
Time > t2
no
END
no
MIL
- 41 -
Heater sensor downstream catalyst Start of monitoring procedure store normal sensor w/o pulse
no
yes
- 42 -
.07.03.00 Calibrations with ASIC CJ 125/120 .07.03.01 General Description The Lambda control consists of a linear Oxygen sensor upstream catalyst and a 2-point oxygen sensor downstream catalyst.
.07.03.02
Monitor function description The following checks will be performed on the linear oxygen sensor upstream catalyst: Rationality Check Any deviation from the characteristic curve of oxygen sensor upstream catalyst due to poison, ceramic cracks, characteristic shift down (CSD) or a leakage between both Oxygen sensors will be detected by the control loop downstream catalyst and by comparison of the sensor signals. The integrator value of the second control loop detects small shifts of the sensor characteristic to lean or to rich. The signal comparison during steady state conditions quickly detects major deviations in sensor characteristics caused by serious faults (e.g. ceramic cracks). For the fault decision the downstream Oxygen sensor has to be checked too (Oscillation and/or fuel cut-off check). Heater Coupling Check This monitoring function will detect any short circuits between sensor heater and the Nernst cell of the Oxygen sensor by watching the Lambda signal. The ECM checks the Lambda value variation. The heater is operated by a pulsating signal with a frequency of two Hertz. The sensor signal characteristic is checked for noises with a significant level and a frequency of the heater operation. If the level of noises is greater than a threshold, a low resistance short cut between heater and pump current or the current of the Nernst cell is detected. Dynamic Check Any change in the dynamic behaviour of the Oxygen sensor due to ageing, heater fault or contamination will be detected by check of actual amplitude ratio check with stored values. Wire and IC-Check The hardware of the Oxygen sensor consists of an IC (CJ 125) with the capability of self-diagnostics. The self-diagnostic functions of the IC detects communication faults between ECM and the sensor, insufficient voltage supply, shorts in the sensor lines to ground and to battery. Open wire on the four sensor lines, adjustment line (IA), virtual mass line (VM), pump current line (IP) and Nernst voltage (UN) will be detected by a system plausibility check. The evaluations of the system plausibility is based on sensor voltage, internal resistance, target Lambda, actual Lambda and the reaction of the controller.
The following checks will be performed on the oxygen sensor downstream catalyst:
- 43 -
Bosch Motronic ME 7, ME 7.1, ME 7.1.1, ME 7.5 System Strategy Oscillation Check The function checks whether the sensor output voltage of the oxygen sensor downstream catalyst always remains above or below a specified threshold. Fuel cut off Check During coasting, the ECM is monitoring the downstream sensor voltage, which has to go below a specific lean threshold. The diagnostic is enabled if coasting was detected for a specific time. Signal check, short to battery check and signal activity check In case the rear O2 sensor readiness is given a certain signal voltage is expected. If the sensor is bellow or above some signal thresholds, a fault will be stored.
- 44 -
.07.03.03
Chart(s) and Flow Chart(s) Flow chart: Rationality Monitoring (Oxygen Sensor Upstream Catalyst)
Start of monitoring procedure
no
yes
read Lambda value upstream sensor
Lambda= 1?
no
no
no
yes
yes
yes
threshold1 < Lambda<threshold2 and voltage <lean threshold or voltage > rich threshold?
no
yes
no
yes
Lambda < Lambda (rich) and voltage< threshold (lean)?
no
no
yes
- 45 -
no
yes
no
correct reaction of sensor voltage?
no
Fault management
yes
yes
MIL
sensor okay downstream sensor voltage < threshold2 within time t1?
no
yes
Flow Chart: Fuel Cut-Off Monitoring (Oxygen Sensors Downstream Catalysts) See other calibrations.
- 46 -
.07.04.00 .07.04.01
Oxygen Sensor Heater Monitoring (ASIC CJ 125/120) General description For proper function of the Oxygen sensors, the sensor element must be heated up. The heating up is controlled by the heater control.
.07.04.02
Monitor function description Linear Oxygen sensor upstream catalyst Any fault in regard to sensor heater will either result in a lost or in a delay of sensor readiness. Oxygen sensor downstream catalyst (2 point sensor) For diagnostic of the sensor heater a specific current pulse is supplied via a load resistance and the voltage is measured. The intern resistance of the sensor heater is calculated with the voltage deviation. The result will be compared with a reference resistance map, which considers ageing and sampling deviations. In case of internal resistance > map resistance the diagnosis stores a fault and the MIL will be illuminated.
- 47 -
.07.04.03
Bosch Motronic ME 7, ME 7.1, ME 7.1.1, ME 7.5 System Strategy Chart(s) and Flow Chart(s) Flow Chart: Oxygen Sensor Heater Control Upstream Catalyst
Check of Entry Conditions Heater Final Stage okay? Wiring of Sensor okay? Sensor IC okay? Calibration Resistor okay? Battery Voltage within range? Heater Control active?
no
Fuel cut off not active Modelled exhaust gas temperature > Threshold Heater Power = Max. Power?
no
no
no
no
Fault Management
Heater Okay!
- 48 -
.07.05.00 .07.05.01
SULEV applications General description The Lambda control consists of a linear Oxygen sensor (LSU) upstream catalyst and two Oxygen sensors (LSF1 and LSF2) downstream front catalyst and post main catalyst. The control loops downstream catalysts correct deviations of the upstream oxygen sensor (LSU). All three sensors are monitored by several single monitoring procedures under the following basic conditions. Monitor function description The following checks will be performed on the linear oxygen sensor (LSU) upstream catalyst: Plausibility Check Any deviation from the characteristic curve of oxygen sensor upstream catalyst due to poison, ceramic cracks, characteristic shift down (CSD) or a leakage between booth Oxygen sensors (LSU and LSF 1) will be detected by the control loop downstream catalyst and by comparison of the sensor signals. The integrator value of the second control loop detects small shifts of the sensor characteristic to lean or to rich. The signal comparison during steady state conditions quickly detects major deviations in sensor characteristics caused by serious faults (e.g. ceramic cracks). For the fault decision the Oxygen sensor downstream the first portion of the catalyst has to be checked too (Oscillation and/or fuel cut-off check). Heater Coupling Check This monitoring function will detect any short circuits between sensor heater and the Nernst cell of the Oxygen sensor by watching the Lambda signal. The ECM checks the Lambda value variation. The heater is operated by a pulsating signal with a frequency of two Hertz. The sensor signal characteristic is checked for noises with a significant level and a frequency of the heater operation. If the level of noises is greater than a threshold, a low resistance short cut between heater and pump current or the current of the Nernst cell is detected. Dynamic Check Any change in the dynamic behavior of the Oxygen sensor due to aging, heater fault or contamination will be detected by watching the slope of the Lambda value during the switch from lean to rich fuel mixture (natural frequency control of fuel mixture active). If the slope of the sensor signal exceeds a specific value the monitoring function is calculating the ratio of actual Lambda slope versus target Lambda slope. If a specific numbers of those slope ratios are less than a threshold, a fault is detected. Check for Sensor at ambient air (out of exhaust system) Under the condition of active injection valves and a Lambda value of < 1.6, a voltage significant less than 4.2 V is expected at the self-diagnostic IC of the LSU. Wire and IC-Check
.07.05.02
- 49 -
Bosch Motronic ME 7, ME 7.1, ME 7.1.1, ME 7.5 System Strategy The hardware of the Oxygen sensor consists of an IC (CJ 125) with the capability of self-diagnostics. The self-diagnostic functions of the IC detects communication faults between ECM and the sensor, insufficient voltage supply, shorts in the sensor lines to ground and to battery. Open wire on the four sensor lines, adjustment line (IA), virtual mass line (VM), pump current line (IP) and Nernst voltage (UN) will be detected by a system plausibility check. The evaluations of the system plausibility is based on sensor voltage, internal resistance, target Lambda, actual Lambda and the reaction of the controller. The following checks will be performed on the oxygen sensors (LSF1 and LSF2) downstream catalyst: Oscillation Check The function checks whether the sensor output voltage of oxygen sensors (LSF 1 and LSF2) downstream catalyst always remains above or below a specified threshold. The second control loop is designed as a natural frequency control and based on the Oxygen sensor (LSF1) post front catalyst. The voltage of the LSF1 triggers the change of fuel mixture. If the trigger point is not crossed although the control loop is closed, a timer is started. In case of no signal change within a specific time, ECM enforces a specific mixture change while watching Oxygen sensor (LSF1) voltage. In case of Oxygen sensor (LSF1) signal shows permanently lean voltage, ECM is forcing an enrichment of mixture. If sensor voltage shows still lean, a stuck low fault is detected. In case of Oxygen sensor (LSF1) signal shows permanently rich voltage, ECM enables lean out of mixture. If sensor voltage shows still rich, ECM is watching the sensor signal during the next coasting condition. In case of no signal change during coasting, a stuck high fault is detected. The third control loop is designed as commanded control and based on the Oxygen sensor (LSF2) post main catalyst. The controller maintains an optimal constant voltage of the third control loop. The target voltage depends on the operating point and is taken from a map. During active control, the target voltage switches between rich and lean. In case of no reaction of the Oxygen sensor (LSF2) output according the commanded control, ECM is forcing the same enrichment/ lean out of fuel mixture in order to monitor the sensor output voltage.
- 50 -
Fuel cut off Check During coasting, the ECM is watching the downstream sensor voltage, which has to go under a specific lean threshold. The diagnostic is enabled if coasting was detected for a specific time and the integrated air mass exceeds a specific threshold. Offset monitoring Oxygen sensor (LSF1) downstream first portion of the catalyst If the integral portion of the third control loop is exceeding a specific threshold while commanded control is active, an offset fault for the Oxygen sensor post front catalyst is detected. Monitoring of electrical errors of sensor upstream and downstream catalyst
Implausible voltages ADC-voltages exceeding the maximum threshold VMAX are caused by a short circuit to UBatt. ADC-voltages falling below the minimum threshold VMIN are caused by a short circuit of sensor signal or sensor ground to ECM ground.
An open circuit of the sensors (upstream and downstream catalyst) can be detected, if the ADC-Voltage is remaining in a specified range after the sensor has been heated.
.07.05.03
engine
catalyst
- 51 -
Flow chart: Plausibility Monitoring (LSU O2 Sensor Upstream Catalyst) SULEV applications
Start of monitoring procedure
no
yes
read Lambda value upstream sensor
Lambda= 1?
no
no
no
yes
yes
yes
threshold1 < Lambda<threshold2 and voltage <lean threshold or voltage > rich threshold?
no
yes
no
yes
Lambda < Lambda (rich) and voltage< threshold (lean)?
no
no
yes
- 52 -
no
yes
no
no fault stored ?
yes
no
correct reaction of sensor voltage?
no
Fault management
yes
yes
MIL
sensor okay downstream sensor voltage < threshold2 within time t1?
no
yes
- 53 -
no
yes
no
yes
no
fault management
yes MIL
sensor okay
- 54 -
no
no
Fault Management
no
- 55 -
.07.06.00 .07.06.01
For proper function of the Oxygen sensors, their ceramic elements must be heated. A non-functioning heater delays or prevents either the sensor readiness (LSU) or the proper signal output (LSF1/LSF2) for closed loop control and thus influences emissions. Oxygen sensor upstream catalyst (LSU) The heater control loop is integrated within the oxygen sensor hardware and has to achieve a target temperature of about 750 C of the ceramic element. Oxygen sensors downstream catalysts (LSF1 and LSF2) For diagnostic of the sensor heater a specific current pulse is supplied via a load resistance and the voltage is measured. The intern resistance of the sensor heater is calculated with the voltage deviation. The result will be compared with a reference map resistance, which considers aging and sampling deviations. In case of internal resistance > map resistance the diagnosis stores a fault and the MIL will be illuminated. .07.06.02 Monitor function description) Monitoring Structure (Oxygen sensor upstream catalyst)
Heater Monitoring of Linear Oxygen Sensor Upstream Catalyst Operating readiness time delay after heater on sensor ready Power stage (final stage) input power stage output power stage Logic delay>threshold & NOT
Sensor heater defective
Heater Control Loop heater input current internal resistance Logic Heter power permant low Heter power permant high
- 56 -
- 57 -
.07.06.03
Flow Chart: LSU, Oxygen Sensor Heater Control Upstream Catalyst (SULEV calibration)
Start of Monitoring Procedure LSU Heater Control Monitor
Check of Entry Conditions Heater Final Stage okay? Wiring of Sensor okay? Sensor IC okay? Calibration Resistor okay? Battery Voltage within range? Heater Control active?
no
No Coasting for a Time> t Commanded Exhaust Modell Temperature> Min. Threshold? Heater Power = Max. Power?
no
Conditions fulfilled? yes no Sensor Element Temp.< Threshold? no yes Internal Resistance < Min. Threshold?
no
no
no
no
Fault Management
Heater Okay!
- 58 -
Heater sensor downstream catalyst Start of monitoring procedure store normal sensor w/o pulse
no
yes
- 59 -
.08.00.00
.09.00.00PCV MONITORING The PCV system assures that no gas from the crankcase system escapes into the atmosphere. All connectors which are not necessary to open during typical maintenance / repair actions are implemented as hard to open. All easy to open connectors are monitored by the OBD system.
The engine cooling system consists of five main parts. 1. The Engine Cooler 2. The Engine Coolant Temperature Sensor 3. The Thermostat Valve 4. The small Cooling Circuit 5. The large Cooling Circuit During heating up the Engine the coolant flows first inside the small cooling circuit. After the coolant reach a sufficient temperature the thermostat valve will open the large cooling circuit to integrate the engine cooler. The engine coolant temperature sensor measures a mixed temperature between the coolant coming from the small and large cooling circuit.
4 2 Engine
- 60 -
.10.01.02
Monitor Functional Description The engine cooling system-monitoring strategy consists of two main diagnostic parts. Engine Cooling System Monitoring
Cooling System
P2181
P3081
P0116
Extended Stuck Check
P0117/P011
Monitoring Procedures
P0116
Each of the engines cooling monitoring function has its own special engine temperature range in which it will be enabled.
P0117
P0116
(stuck
typical data
105 80
thermostat control
P2181
60 40
P0116
(extended)
P3081
-45C
P0118
- 61 -
.10.03.00
Charts and Flow Charts Cooling System Performance (P2081) In case that the engine coolant temperature does not reach an certain value after a sufficient mass air flow under normal driving conditions, the cooling system performance is considered to be reduced.
decision
- 62 -
Parameter Description
thres_01: lowest enable temperature thres_02: highest enable temperature thres_03: fault detection threshold airmas_01: sufficient air mass integral to Allow fault detection
no
yes
air m as integral as indicator of determ ination for energy dissipated (depending on start tem perature and m odel of am bient tem perature)
no
no
secondary param eters (e.g. averarge vehicle speed, average m ass air flow and m odel am bient tem perature) within window?
yes
E C T > thres_03?
no
E nd of m onitoring procedure
- 63 -
Engine Coolant Temp. Sensor Rationality (P3081) In case that the engine coolant temperature does not fit to a reference model temperature in an certain range, the cooling system is defective or the sensor is not in a plausible range.
reference model
wron warming up
fault decision
time
- 64 -
Parameter Description
modmx_01: maximum reference temperature model value range_01: maximum deviation error to detect a malfunction ECT: Engine Coolant Temperature MAF: Mass Air Flow Sensor IAT: Intake Air Temperature
yes
no
MIL
Fault management
- 65 -
Engine Coolant Temperature Sensor Stuck High (P0116) After engine start the system stores continuously the lowest and highest ECT above the thermostat control temperature for a driving cycle. In case that after several driving conditions the difference between ECT max and ECT min is lower than the threshold the sensor stuck at high values.
fault decision
H1
L1
H2
Ln-1
Hn-1
Ln
Hn driving conditions
H: driving condition with high cooling performance (vehicle cruise) L: driving conditions with low cooling performance (idle)
- 66 -
Parameter Description
Start of monitoring procedure
Engine start temperature within window? temp_01/temp_02 yes Reset: ECT min. and ECT max.
no
temp_01: maximum engine start temperature temp_02: substitute model temp thres_01: maximum diff. between ECTmin/ ECT max to detect a malfunction ECTmin: Minimum of stored Engine Coolant temperature ECTmax: Maximum of stored Engine Coolant temperature
yes
Sensor okay!
no
yes
- 67 -
Engine Coolant Temperature Sensor Stuck Low (P0116) After engine start the system stores continuously the lowest and highest ECT below the thermostat control temperature for a driving cycle. In case that after several driving conditions the difference between ECT max and ECT min is lower than the threshold the sensor stuck at low values.
H1
L1
H2
Ln-1
Hn-1
Ln
Hn
H: driving condition with high cooling performance (vehicle cruise) L: driving conditions with low cooling performance (idle)
- 68 -
Bosch Motronic ME 7, ME 7.1, ME 7.1.1, ME 7.5 System Strategy Flow Chart Engine Coolant Temperature Sensor Stuck Low (P0116)
Parameter Description
Start of monitoring procedure
Engine start temperature within window? temp_01/temp_02 yes Reset: ECT min. and ECT max.
no
temp_01: maximum engine start temperature temp_02: substitute model temperature thres_01: maximum diff. between ECTmin/ ECT max to detect a malfunction ECTmin: Minimum of stored Engine Coolant temperature ECTmax: Maximum of stored Engine Coolant temperature
yes
Sensor okay!
no
yes
- 69 -
Flow Chart Engine Coolant Temperature Sensor Stuck Test (all temperatures above threshold) (P0116) Monitoring of engine temperature during normal DCY and during engine shut off time
Part I:
Engine Start
ECT @ engine start above threshold yes Measure and store continuously: ECT min. / ECT max.
no
Sufficient time in driving conditions during DCY yes ECT max. - ECT min. > threshold f(ECT at start) ? no no Engine off ? End of monitoring yes yes Sensor okay
Part II
- 70 -
Bosch Motronic ME 7, ME 7.1, ME 7.1.1, ME 7.5 System Strategy Monitoring of engine temperature during normal DCY and during engine shut off time
yes
no
MIL
Fault management
End of monitoring
- 71 -
Bosch Motronic ME 7, ME 7.1, ME 7.1.1, ME 7.5 System Strategy The signal of Engine Coolant Temperature Sensor is evaluated and considered to be electrically out of range if either the upper or the lower thresholds is exceeded.
Check routine for upper threshold (depending on engine rpm and throttle position)
NO
Signal < lower threshold
YES
YES
Signal > upper threshold
NO
MIL
- 72 -
COLD START EMISSION REDUCTION STRATEGY MONITORING Not applicable AIR CONDITIONING (A/C) SYSTEM COMPONENT MONITORING Not applicable VARIABLE VALVE TIMING AND/OR CONTROL (VVT) SYSTEM MONITORING Not applicable DIRECT OZON REDUCTION (DOR) SYSTEM MONITORING Not applicable PARTICULATE MATER (PM) TRAP MONITORING Not applicable COMPREHENSIVE COMPONENTS MONITORING Flow Charts in addition to the summary table explanations: Injection Valve Check is performed while using Output Stage Check 16.09.12: Fuel Pump Relay Check is performed while using Output Stage Check 16.09.12:
- 73 -
.16.03.00
No fuel tank ventilation with high degree of saturation No active diagnosis of EVAP system and secondary air No vehicle speed fault No throttle position fault No ECT fault No intake air temperature fault No eve. purge valve fault No limp home of engine speed sensor Idle switch closed Vehicle speed = 0 mph Engine speed @ idle ECT > 59.25 C
NO
Idle Controller @ max. Limit and Engine rpm < Idle rpm - 80 rpm and Engine Load < Threshold?
YES
NO
Idle Controller @ min. Limit and Engine rpm > Idle rpm + 80 rpm
NO
- 74 -
Bosch Motronic ME 7, ME 7.1, ME 7.1.1, ME 7.5 System Strategy .16.04.00 Engine Speed Sensor:
Start of monitoring
no
no
yes
yes
MIL on
.16.05.00
- 75 -
.16.06.00
IAT MAF ECT Camshaft position sensor Charge pressure control valve
NO
YES
YES
NO
MIL
Fault Management
- 76 -
Bosch Motronic ME 7, ME 7.1, ME 7.1.1, ME 7.5 System Strategy .16.07.00 Rationality Mass Air Flow Sensor (MAF)
no
mass air flow < lower threshold or mass air flow > upper threshold
yes
Sensor okay
Fault management
yes
mass air flow vs. calculated mass air flow > threshold and fuel system adaptation < threshold
mass air flow vs. calculated mass air flow < threshold and fuel system adaptation > threshold yes
no Sensor okay
no
- 77 -
no Sensors okay
to ta l m a s s a ir flo w < lo w e r th re sh o ld or to ta l m a s s a ir flo w > u p p e r th re sh o ld or to ta l m a s s a ir flo w vs . c a lcu la te d m a s s a ir flo w > th re s h o ld a n d fu e l a d a p ta tio n < th re sh o ld or to ta l m a s s a ir flo w vs . c a lcu la te d m a s s a ir flo w < th re s h o ld a n d fu e l a d a p ta tio n > th re sh o ld
yes
MIL
pinpointing:
yes
no
mass air flow MAF1 < lower threshold or mass air flow MAF1 > upper threshold or total mass air flow vs calculatedmass air flow > threshold and fuel adaptation < threshold or total mass air flow vs calculatedmass air flow < threshold and fueladaptation > threshold
mass air flow MAF2 < lower threshold or mass air flow MAF2 > upper threshold or total mass air flow vs calculatedmass air flow > threshold and fuel adaptation < threshold or total mass air flow vs calculatedmass air flow < threshold and fueladaptation > threshold
no
yes
MIL
yes
Fault MAF 1
Fault MAF 2
- 78 -
.16.08.00
NO
coasting condition?
NO
YES
NO
YES
- 79 -
.16.09.00
Throttle Position Sensor (throttle unit with E-gas actuator) The throttle body consists of two potentiometers (reversed voltage logic). During the first start, the potentiometer characteristics are adapted and stored. The diagnostic monitors the corrected values of potentiometer 1 and 2. In the case of a higher difference than a threshold value both signals are compared to the engine load to determine and disable the faulty one. A fault code will be stored and the MIL will be illuminated.
no
no
yes
yes
no rationality check TPS 1 - calc. value >TPS2-calc. value or TPS1-calc.value > thresh_02 yes rationality check TPS 2 - calc.value >TPS1-calc. value or TPS2-calc.value >thresh_02 yes
no
no
sensor okay
fault management
MIL
- 80 -
.16.10.00
no
yes
yes
MIL no no
sensors okay
- 81 -
.16.11.00
yes
no
yes
- 82 -
.16.12.00
Start
no
Enable? yes
no Actual cp > modeled cp + threshold yes Charge pressure too high Actual cp + threshold< modeled cp yes Charge pressure too low no
Fault management
MIL
End
- 83 -
.16.13.00
Signals on lines "KL50" and "KL50R" high KL50 low high KL50R low
no
engine coolant temperature > min. threshold and < max. threshold?
Delay Time
yes
no
Start counter with signal high on KL50, stop counter with signal high on KL50R and calculate delay time!
yes
no
engine cranking?
no
yes
yes
- 84 -
.16.14.00 .16.14.01
Exhaust Temperature Sensor (SULEV) General Monitoring Description The exhaust temperature sensor (ETS) is monitored for rationality during engine cold start, where engine coolant temperature, intake air temperature and exhaust temperature are expected within the same temperature range (stuck high check). Monitor function description After engine has been cold started the slope of ETS is monitored and should not be higher than a max. Threshold and not lower than a min. threshold. Both plausibility checks are completed before the ETS information is used in other monitors (e.g. secondary air). Additionally the final stage check monitors for shorts to ground or to battery.
.16.14.02
- 85 -
.16.14.03
no
yes
Engine Cold Start Condition: Intake Air Temperature(IATS) within range? Engine Coolant Temperature (ECTS) within range? IATS-ECTS<threshold? Engine shut-off temperature > threshold?
no
yes
no
yes
no
MIL
yes
Fault management
- 86 -
- 87 -
.16.20.00
Automatic Transmission Monitor VW/Audi has different basic Automatic transmission systems. For each of these systems we are providing an OBD II summary table. Common OBD description from VW/Audi table TCM Groups show the references between transmission type and test groups.
.16.21.00
Output Stage Check The output stages are integrated in manufacturer specific IC's: The IC has a binary diagnostic line (e.g. SJ401). If the control line of one stage has a different signal than the output line, the logic circuit inside the IC detects a malfunction. The logic circuit within the IC can separate the type of fault to a short circuit to minus, an open line, or a short circuit to plus. The check result will be sent to the ECM via diagnosis line. Signal tables of output stage check
Wiring Defective
Low
high
High
Low
High
Low
high
>2.2-3.0A
No fault
faut
Wiring Defective
Low
high
High
Low
High
Low
high
>2.2-3.0A
fault
- 88 -
OTHER EMISSION CONTROL OR SOURCE SYSTEM MONITORING N.A. EXEMPTIONS TO MONITOR REQUIREMENTS N.A. RESERVED N.A.
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Bosch Motronic ME 7, ME 7.1, ME 7.1.1, ME 7.5 System Strategy .20.00.00 PARAMETERS AND CONDITIONS FOR CLOSED LOOP OPERATION General The highest conversion efficiency of the catalyst is given in a small window of air-fuel mixture close to the ratio of Lambda=1. Therefore a combination of two (three for SULEV) control loops is used to achieve the conditions for highest conversion capability of the catalyst. The first control loop uses the signal of the first Oxygen sensor (pre catalyst) to correct the air fuel ratio by adjusting the injection time. The second and third control loop uses the signals of the middle (SULEV) and post catalyst Oxygen sensors. These control loops perform a fine-tuning of the air / fuel ratio to optimise the catalytic conversion. The first control loop has a quicker response time than the post control loops, which are depending on the death time of the exhaust systems. Therefore the adjustment ranges for the post control loops are restricted and the response time is larger than the one of the first control loop. Conditions for closed loop operation of the first control loop The main condition for closed loop is a proper heated up Oxygen sensor and the dew point must be exceeded. To guaranty the Oxygen sensor readiness the heat-up strategy starts depending on engine temperature first on a low level of heater power. Upon the exhaust temperature reaches a level where no liquid water is expected to be in the exhaust system the heater power is controlled to achieve normal ceramic temperature of the Oxygen sensor. The ceramic temperature has to be >350 C for binary and >685 C linear sensors. Specific temperatures are mentioned in the individual summary tables of the concepts. Additional heat-up of the Oxygen sensor is caused by the thermal energy of the exhaust gas. The engine management system evaluates permanently engine temperature and thermal energy introduced to calculate the exhaust temperature based on a model. The main value therefore is the integrated air mass after engine start. Upon the integrated air mass exceeds an applicable threshold, depending on engine start temperature, the due point is exceeded. In that case, the heater power will be increased until the sensor readiness is achieved and sensor is considered to be ready for closed loop control. The criteria for sensor readiness of a binary sensor are: No fault from heater final stage check Sensor signal is out of a range 0,4V<sensor voltage<0,5V Heater power > 50% within a certain time (typically 8-10 s) The criteria for sensor readiness of the linear are: No fault from LSU-Heater, LSU-Signals and LSU-IC LSU is heated up to a ceramic-temperature of > 685C or the internal sensor resistor Ri < 130 .
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Parameters evaluated to begin closed loop (first control loop) The target is to begin closed loop operation in a very early state after engine start. However closed loop is delayed if engine is operated according the catalyst heat-up strategy. In the table below the importance parameters are listed. Parameter / System Oxygen Sensor Condition/Evaluation No fault detected in Oxygen sensor, wiring of the sensor or the sensor IC (linear sensors). Exhaust Temperature > threshold, calculated based on mass airflow integral. Sensor heated up, evaluated based on heater resistance. Integrated air mass > threshold OBD evaluation on sensor heater finished without fault Calculated value based on mass airflow and fuel injection. Signal used to trigger the model calculation. Monitor Oxygen sensor monitor for the front sensor(s)
Oxygen Sensor Readiness Mass Air Flow Oxygen Sensor Heater Engine Load
Monitor of the mass air flow meter (out of range, rationality) Monitored by diagnostic of the heater control. Out of range / rationality Oxygen sensor heater monitor. Fuel system monitor, mass air flow meter monitor Monitor for engine coolant temperature sensor (out of range, rationality). Monitor of the cooling system (rationality). Monitor for the intake air temperature sensor (out of range) Monitor for the secondary air system. Monitor for the fuel injectors (out of range). Fuel system monitor Monitor for the ignition system (out of range). Misfire monitor.
Engine Temperature
Signal used to trigger the model calculation. No fault in the secondary air system is detected by OBD. OBD evaluation on injectors finished without fault OBD evaluation on ignition system finished without fault. No misfire detected.
Ignition system
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Continuity of closed loop operation (first control loop) The closed loop operation is the most dominant operation mode for the fuel system. Despite that fact, there are operating conditions of the engine where closed loop control must be temporary disabled. Parameter / System Target Lambda Condition/Evaluation Control range is within normal values of Lambda (0.8<<1.5) Engine load is too low, to control the exhaust lambda value during SAI (typically relative engine load<15%) During the monitor of air injection the target Lambda is commanded to determine deviation cause by air mass. Injection time is not at minimum threshold. Injection is not disabled. Fuel cut is not commanded (e.g. coasting) Monitor Fuel system monitor, mass air flow meter monitor, oxygen sensor monitor Fuel system monitor, mass air flow meter monitor, oxygen sensor monitor Fuel system monitor, mass air flow meter monitor
Engine load
Fuel Injection
Monitor for the ignition/injection system (out of range). Misfire monitor. Fuel system monitor
Typical Values Given a normal cold started FTP (around 20C) most of the concepts reaches the closed loop condition for the first control loop within 20s to 60s. Additionally closed loop is forced depending on engine start temperature after a maximum time. Vehicles produced in MY 2004 and MY 2005 Engine Start Temperature Temperature> 10 C Temperature >-6.7 C and < 10C Time, when closed loop is forced 120 s 300 s
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Bosch Motronic ME 7, ME 7.1, ME 7.1.1, ME 7.5 System Strategy PARAMETERS / CONDITIONS FOR 2ND CLOSED LOOP OPERATION Conditions for closed loop operation of the second control loop As already mentioned under General the 2nd control loop optimises the adjustments of the first control loop over a longer time to achieve the maximum conversion of the catalyst in a very small window of air/fuel ratio close to Lambda=1. The second control loop uses a binary Oxygen sensor, which is operated at a target value of sensor output voltage. Deviations from the target voltage are corrected by adjusting the air/fuel ratio until the target voltage is achieved again. The controller of the 2nd control loop is a combination of proportional and integral (PI-) controller. The proportional and the integral portion of the controller have individual enable criteria.
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Parameters evaluated to begin closed loop (second control loop) Enable criteria for P-portion of the controller The proportional-portion of the controller corrects short-term deviations and achieves the target sensor output voltage. Condition/Evaluation No fault detected in wiring of the sensor or the sensor IC (linear sensors). Fuel control performs normal, no fault is detected and fuel control is not temporarily disabled. nd Oxygen Sensor for 2 control Sensor heated up, a loop readiness minimum power was delivered to the heater, sensor voltage has left the voltage range of a cold sensor Catalyst model temperature Exhaust Temperature > threshold, calculated based on mass airflow integral, ignition timing, lambda value, vehicle speed. Variable Valve Timing System (if applicable) Secondary Air System EVAP purge System Mass Air Flow Meter Controller range for the first control loop is not at the threshold limit. No fault detected No fault detected No fault detected No fault detected Controller for the first control loop not at minimum or maximum threshold Parameter / System Closed loop condition for the first control loop. Minimum of integrated mass airflow passed. Monitor Oxygen sensor monitor for the front sensor(s). Monitor of the mass air flow meter (out of range, rationality). Fuel system monitor Monitored by diagnostic of the heater monitor and sensor-wiring monitor.
Monitor of the mass air flow meter (out of range, rationality) Fuel system monitor, oxygen sensor monitor, vehicle speed sensor monitor VVT monitor AIR System monitor EVAP purge monitor Mass Air Flow Meter monitor Oxygen sensor monitor
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Enable criteria for adaptive I-portion of the controller (additionally) The integral-portion of the controller corrects permanent deviations / shifts over a longer time by adjusting the adaptation. Parameter / System Engine speed/load within a normal operating range Condition/Evaluation Engine Speed within 15004000 rpm Engine Load within 20-60% Monitor Engine Speed Sensor monitor, Mass Air Flow Meter monitor, and fuel system monitor.
(Typical values; may differ on individual concepts) Carbon Canister of the EVAP High load of carbon canister system indicated during EVAP purge. Minimum of integrated mass Oxygen sensor voltage of 2nd airflow passed and P-portion control loop, P-portion of of controller achieves target controller for 2nd control loop range for Oxygen sensor voltage already.
EVAP purge monitor. Oxygen sensor monitor for secondary sensor(s). Fuel system monitor
Typical Values (second control loop) Given a normal cold started FTP (around 20C) most of the concepts reaches the closed loop condition for the second control loop within 60s to 100s.
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PARAMETERS / CONDITIONS FOR CLOSED LOOP OPERATION ON SULEV General The SULEV concept consists of 2 catalysts and 3 control loops. The first control loop uses the Oxygen sensor pre catalyst (LSU) in the same manner conventional concepts does. The Oxygen sensor between the two bricks (LSF1) of the catalyst is the input for the second and the Oxygen sensor after the last brick (LSF2) is the input for the third control loop. Both sensors are binary Oxygen sensors. The closed loop operation of each of the control loops are in a depending order of 1st, 2nd and 3rd control loop. In comparison to post catalyst control loop on conventional concepts the 2nd and 3rd control loop are high precision loops with specific requirements for short-term correction and long-term adaptation. The driving conditions have to be stable and constant to allow any corrections by these control loops. The allowed correction steps are much smaller in comparison to post catalyst control loop applications on conventional concepts.
Conditions for closed loop operation of the first control loop The conditions for closed loop operation of the first control loop on the SULEV concept are the same as described for conventional concepts. Conditions for closed loop operation of the second control loop The second control loop on the SULEV concept is designed as natural frequency control loop and is based on a binary Oxygen sensor. The controller has the same capability in achieving maximum conversion on the first brick of the catalyst by using a proportional adjustment range for shortterm correction and an integral adjustment range for long-term adaptation (PI-controller). Both controller ranges have individual conditions for closed loop operation.
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Enable criteria for P-portion of the controller of second control loop (SULEV) The proportional-portion of the controller corrects short-term deviations. Condition/Evaluation No fault detected in wiring of the sensor or the sensor IC (linear sensors). Fuel control performs normal, no fault is detected and fuel control is not temporarily disabled. Oxygen Sensor for 2nd control Sensor heated up, a loop readiness minimum power was delivered to the heater, sensor voltage has left the voltage range of a cold sensor Engine Coolant Temperature Engine coolant temperature has raised above a limit value of 50 C (Typical temperature value; may differ on specific application) Catalyst model temperature Exhaust Temperature > threshold (above light-off temperature), calculated based on mass airflow integral, ignition timing, lambda value, vehicle speed. Variable Valve Timing No fault detected System (if applicable) Secondary Air System No fault detected EVAP purge System No fault detected Mass Air Flow Meter No fault detected Controller range for the first Controller for the first control control loop loop not at minimum or maximum threshold Parameter / System Closed loop condition for the first control loop. Minimum of integrated mass airflow passed. Monitor Oxygen sensor monitor for the front sensor(s). Monitor of the mass air flow meter (out of range, rationality). Fuel system monitor Monitored by diagnostic of the heater monitor and sensor-wiring monitor.
Monitor of the mass air flow meter (out of range, rationality) Fuel system monitor, oxygen sensor monitor, vehicle speed sensor monitor VVT monitor AIR System monitor EVAP purge monitor Mass Air Flow Meter monitor Oxygen sensor monitor
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Enable criteria for adaptive I-portion of the controller second control loop (additionally) The integral-portion of the controller corrects permanent deviations / shifts over a longer time by adjusting the adaptation. Parameter / System Engine speed/load within a normal operating range Condition/Evaluation Engine Speed within 15005000 rpm Engine Load within 15-100% Monitor Engine Speed Sensor monitor, Mass Air Flow Meter monitor, and fuel system monitor.
(Typical values; may differ on individual concepts) Carbon Canister of the EVAP High load of carbon canister system indicated during EVAP purge. Minimum of integrated mass Oxygen sensor voltage of 2nd airflow passed and P-portion control loop, P-portion of of controller achieves target controller for 2nd control loop range for Oxygen sensor voltage already. Typical Values (second control loop)
EVAP purge monitor. Oxygen sensor monitor for secondary sensor(s). Fuel system monitor
Given a normal cold started FTP (around 20C) most of the concepts reaches the closed loop condition for the second control loop within 60s to 80s.
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Conditions for closed loop operation of the third control loop The third control loop is designed like the second control loop on conventional concepts and achieves the maximum conversion of the 2nd brick of the catalyst. The controller consists of very restricted correction ranges for the short-term proportional and the long-term integral adaptive portion (PI-controller). Both controller ranges have individual conditions for closed loop operation. Enable criteria for P-portion of the controller of third control loop (SULEV) The proportional-portion of the controller corrects short-term deviations. Parameter / System Closed loop condition for the first control loop. Minimum of integrated mass airflow passed. Condition/Evaluation No fault detected in wiring of the sensor or the sensor IC (linear sensors). Fuel control performs normal, no fault is detected and fuel control is not temporarily disabled. No fault detected in LSU System (Sensor, wiring, IC) and no fault at LSF1 and LSF2. Fuel control performs normal, no fault is detected and fuel control is not temporarily disabled. Monitor Oxygen sensor monitor for the front sensor(s). Monitor of the mass air flow meter (out of range, rationality). Fuel system monitor Oxygen sensor monitor for the front sensor(s). Oxygen sensor monitor for the first downstream sensor(s) and Oxygen sensor monitor for the second downstream sensor(s). Monitor of the mass air flow meter (out of range, rationality). Fuel system monitor Monitored by diagnostic of the heater monitor and sensor-wiring monitor.
Closed loop condition for the second control loop. Minimum of integrated mass airflow passed.
Oxygen Sensor for 3rd control Sensor heated up, a loop readiness minimum power was delivered to the heater, sensor voltage has left the voltage range of a cold sensor Monitor of the mass air flow Catalyst model temperature Exhaust Temperature > meter (out of range, threshold (above light-off rationality) Fuel system temperature), calculated monitor, oxygen sensor based on mass airflow monitor, vehicle speed sensor integral, ignition timing, lambda value, vehicle speed. monitor Variable Valve Timing No fault detected VVT monitor System (if applicable) Secondary Air System No fault detected AIR System monitor EVAP purge System No fault detected EVAP purge monitor Mass Air Flow Meter No fault detected Mass Air Flow Meter monitor Controller range for the first Controller for the first control Oxygen sensor monitor control loop loop not at minimum or maximum threshold (LSU: Linear Oxygen Sensor, LSF1: 1st Binary Oxygen Sensor, LSF2: 2nd Binary Oxygen Sensor)
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Enable criteria for adaptive I-portion of the controller third control loop (additionally) The integral-portion of the controller corrects permanent deviations / shifts over a longer time by adjusting the adaptation. Parameter / System Engine speed/load within a normal operating range Condition/Evaluation Engine Speed within 27003500 rpm Engine Load within 25-45% Monitor Engine Speed Sensor monitor, Mass Air Flow Meter monitor, and fuel system monitor.
(Typical values; may differ on individual concepts) Carbon Canister of the EVAP High load of carbon canister system indicated during EVAP purge. Minimum of integrated mass Oxygen sensor voltage of 2nd airflow passed and P-portion control loop, P-portion of of controller achieves target controller for 2nd control loop range for Oxygen sensor voltage already. Typical Values (third control loop)
EVAP purge monitor. Oxygen sensor monitor for secondary sensor(s). Fuel system monitor
Given a normal cold started FTP (around 20C) most of the concepts reaches the closed loop condition for the third control loop within 90s to 100s.
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