9/30/22, 2:45 PM SIS 2.

2019/06/05 Sensor Signal (Analog, Active) - Test - Sensors on the J2 ECM Connector (UENR0668-58)

SMCS - 1439 i07729674

This procedure covers the following diagnostic codes:

Diagnostic Codes for the Active Analog Sensors

J1939 CDL Code Description

(code descriptions may Comments
Code Code vary)

The Electronic Control Module (ECM) detects the following conditions:

The signal voltage from the engine oil pressure sensor is greater than 4.8 VDC for more than 8
Engine Oil Pressure : seconds.
100-3 100-3
Voltage Above Normal
The warning lamp will come on. The ECM will log the diagnostic code. The ECM will set data for
engine oil pressure to the default value. The default engine oil pressure is 600 kPa (87 psi). The
electronic service tool will display "Voltage Above Normal" on the status screens.
The ECM detects the following conditions:

The signal voltage from the engine oil pressure sensor is less than 0.2 VDC for more than 8
seconds.
Engine Oil Pressure :
100-4 100-4
Voltage Below Normal The ECM has been powered for at least 2 seconds.

The warning lamp will come on. The ECM will log the diagnostic code. The ECM will set data for
the engine oil pressure to the default value. The default engine oil pressure is 600 kPa (87 psi).
The electronic service tool will display "Voltage Below Normal" on the status screens.
The ECM detects the following conditions:

3528- Barometric Pressure : The signal voltage for the barometric pressure sensor is greater than 4.8 VDC for at least 8
108-3
3 Voltage Above Normal seconds.

The warning lamp will come on. The ECM will log the diagnostic code.
The ECM detects the following conditions:

3528- Barometric Pressure : The signal voltage for the barometric pressure sensor is less than 0.2 VDC for at least 8
108-4
4 Voltage Below Normal seconds.

The warning lamp will come on. The ECM will log the diagnostic code.
The ECM detects the following conditions:

The signal voltage for the fuel rail pressure sensor is more than 4.7 VDC for 0.6 seconds.
Engine Injector Metering Rail
1797-
157-3 #1 Pressure : Voltage Above
3 The warning lamp will flash. The ECM will log the diagnostic code. The electronic service tool will
Normal
display "70000 kPa" next to "Desired Fuel Rail Pressure" and "Actual Fuel Rail Pressure" on the
status screens.
The engine will be derated.
The ECM detects the following conditions:

The signal voltage for the fuel rail pressure sensor is less than 0.67 VDC for 0.6 seconds.
Engine Injector Metering Rail
1797-
157-4 #1 Pressure : Voltage Below
4 The warning lamp will flash. The ECM will log the diagnostic code.
Normal
The electronic service tool will display "70000 kPa" next to "Desired Fuel Rail Pressure" and
"Actual Fuel Rail Pressure" on the status screens.
The engine will be derated.
The ECM detects the following conditions:

The fuel rail pressure sensor has failed.

157- 1797- Engine Injector Metering Rail
12 12 #1 Pressure : Failure The warning lamp will flash. The ECM will log the diagnostic code.
The electronic service tool will display "70000 kPa" next to "Desired Fuel Rail Pressure" and
"Actual Fuel Rail Pressure" on the status screens.
The engine will be derated.
The ECM detects the following conditions:

Engine Exhaust Gas The signal voltage for the NOx Reduction System (NRS) differential pressure sensor is not
3387- Recirculation Differential stable.
411-2
2 Pressure : Erratic,
Intermittent, or Incorrect The ECM has been powered for at least 0.24 seconds.

The warning light will come on. The ECM will log the diagnostic code.

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The ECM detects the following conditions:

Engine Exhaust Gas The signal voltage for the NOx Reduction System (NRS) differential pressure sensor is more
3387- Recirculation Differential than 4.8 VDC.
411-3
3 Pressure : Voltage Above
Normal The ECM has been powered for at least 0.24 seconds.

The warning light will come on. The ECM will log the diagnostic code.
The ECM detects the following conditions:
Engine Exhaust Gas
The signal voltage for the NRS differential pressure sensor is less than 0.2 VDC.
3387- Recirculation Differential
411-4
4 Pressure : Voltage Below
The ECM has been powered for at least 0.24 seconds.
Normal
The warning light will come on. The ECM will log the diagnostic code.
The ECM detects the following conditions:

The signal voltage from the NRS inlet pressure sensor is more than 4.8 VDC for 0.12 seconds.
Engine Exhaust Gas
3358- 3385-
Recirculation Inlet Pressure : The ECM has been powered for 2 seconds.
3 3
Voltage Above Normal
The warning light will come on. The ECM will log the diagnostic code.
The ECM will set data for the NRS inlet pressure to the default value. The default value for the
NRS inlet pressure is 250 kPa (36.3 psi).
The ECM detects the following conditions:

The signal voltage for the NRS inlet pressure sensor is less than 0.2 VDC for 0.12 seconds.
Engine Exhaust Gas
3358- 3385-
Recirculation Inlet Pressure : The ECM has been powered for 2 seconds.
4 4
Voltage Below Normal
The warning light will come on. The ECM will log the diagnostic code.
The ECM will set data for the NRS inlet pressure to the default value. The default value for the
NRS inlet pressure is 250 kPa (36.3 psi).
The ECM detects the following conditions:

The signal voltage from the intake manifold pressure sensor is above 4.8 VDC for at least 8
seconds.

The ECM has been powered for 2 seconds.

Engine Intake Manifold #1
3563- 1785-
Absolute Pressure : Voltage The warning light will come on. The ECM will log the diagnostic code.
3 3
Above Normal The data for the intake manifold pressure will be set to a maximum valid pressure for 2 seconds.
The ECM will then flag the intake manifold pressure as being invalid. A default value is then used
for the intake manifold pressure.
The current for the wastegate regulator will be set to a default value while this code is active.
This condition will cause the engine to have poor acceleration. The default setting will prevent
any overpressure in the intake manifold which could be caused by an overspeed of the
turbocharger.
The ECM detects the following conditions:

The signal voltage from the intake manifold pressure sensor is less than 0.2 VDC for at least 8
seconds.

The ECM has been powered for 2 seconds.

Engine Intake Manifold #1
3563- 1785-
Absolute Pressure : Voltage The warning light will come on. The ECM will log the diagnostic code.
4 4
Below Normal The data for the intake manifold pressure will be set to a maximum valid pressure for 2 seconds.
The ECM will then flag the intake manifold pressure as being invalid. A default value is then used
for intake manifold pressure.
The current for the wastegate regulator will be set to a default value while this code is active.
This condition will cause the engine to have poor acceleration. The default setting will prevent
any overpressure in the intake manifold which could be caused by an overspeed of the
turbocharger.
Follow the troubleshooting procedure to identify the root cause of the fault.

Table 1

The following conditions must exist before any of the above codes will become active:

There are no active 3509 or 262 codes.

There are no active 168 codes.

The following background information is related to this procedure:

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The 5 VDC sensor supply provides power to all 5 VDC sensors. The ECM supplies 5 VDC to terminal "3" of the fuel rail pressure sensor connector
and to terminal "1" of all other active sensor connectors. The sensor common from the ECM connector goes to terminal "1" of the connector for the
fuel rail pressure sensor. The sensor common from the ECM connector goes to terminal "2" of all other active sensor connectors. The sensor
supply is output short circuit protected. A short circuit to the battery will not damage the circuit inside the ECM.

The 8 VDC sensor supply provides power to the exhaust outlet temperature sensor. The ECM supplies 8 VDC to terminal "1" of the exhaust outlet
temperature sensor connector. The sensor common from the ECM connector goes to terminal "2" of the connector for the exhaust outlet
temperature sensor. The sensor supply is output short circuit protected. A short circuit to the battery will not damage the circuit inside the ECM.

Pull-up Voltage

The ECM continuously outputs a pull-up voltage on the circuit for the sensor signal wire. The ECM uses this pull-up voltage to detect an open in the
signal circuit. When the ECM detects a voltage above a threshold on the signal circuit, an open circuit diagnostic code (XXXX-3) is generated for
the sensor.

If the sensor is disconnected, pull-up voltage indicates that the wires from the sensor connector to the ECM are not open or shorted to ground. If
the sensor is disconnected, the absence of pull-up voltage indicates an open in the signal wire or a short to ground. If the sensor is disconnected
and the voltage is different from pull-up voltage, the signal wire is shorted to another wire in the harness.

Illustration 1 g06308935
Schematic for the active sensors on the ECM J2 connector

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Illustration 2 g06308941
Pin locations on the P2 connector for the active sensors
(1) 5 VDC supply
(10) Sensor ground
(29) NRS differential pressure sensor signal
(37) Fuel rail pressure sensor signal
(45) Barometric pressure sensor signal
(46) NRS inlet pressure sensor signal
(53) Oil pressure sensor signal
(54) Intake manifold pressure sensor signal

Illustration 3 g03374231
Fuel rail pressure sensor
(1) Ground
(2) Signal
(3) 5 VDC Supply

Illustration 4 g01170310
Typical example of an engine pressure sensor
(1) 5 VDC Supply
(2) Ground
(3) Signal

Troubleshooting Test Steps Values Results

1. Inspect Electrical Connectors and Wiring

A. Thoroughly inspect the terminal connections on the Result: There is a fault in a connector or the wiring.
P2/J2 ECM connectors and the engine pressure sensors.
Refer to Troubleshooting, "Electrical Connectors - Repair: Repair any faulty connectors or replace the wiring harness.
Inspect". Ensure that all the seals are properly in place and ensure that the
Loose connectors are correctly coupled.
B. Perform a 45 N (10 lb) pull test on each of the wires in connection Use the electronic service tool to clear all logged diagnostic codes and
the ECM connector and the sensor connectors that are or verify that the repair eliminates the fault.
associated with the active diagnostic code. damaged
wire Result: All connectors, pins, and sockets are correctly coupled and/or
C. Check the screw for the ECM connector for the correct inserted. The harness is free of corrosion, abrasion, and pinch points.
torque of 6 N·m (53 lb in).
Proceed to Test Step 2.
D. Check the harness for corrosion, abrasion, and pinch
points from the engine pressure sensors to the ECM.

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2. Check For Active Diagnostic Codes

Result: There are no active diagnostic codes for the active sensors.
A. Turn the keyswitch to the OFF position.
Repair: If there are logged diagnostic codes for the active sensors, the
B. Connect the electronic service tool to the diagnostic
fault may be intermittent.
connector.
Diagnostic Refer to Troubleshooting, "Electrical Connectors - Inspect" to identify
C. Turn the keyswitch to the ON position. Wait at least 10
codes intermittent faults.
seconds for activation of the diagnostic codes.
Result: A diagnostic code that is listed in Table 1 is active.
D. Verify if any of the diagnostic codes that are listed in
Table 1 are active.
Proceed to Test Step 3.
E. Turn the keyswitch to the OFF position.

3. Check the Supply Voltage at the Sensor Connector

A. Turn the keyswitch to the OFF position.

Result: The voltage measurement is not within the expected range. The
fault is in the supply wire or the ground wire in the engine wiring harness.
B. Disconnect the connector for the suspect sensor.
Repair: Repair the faulty wiring or replace the faulty wiring.
C. Turn the keyswitch to the ON position. Do not start the
engine.
4.8 VDC Use the electronic service tool to clear all logged diagnostic codes.
to 5.2 Return the engine to service.
D. Measure the voltage between the supply terminal and
VDC
the ground terminal on the harness connector for the
Result: The voltage measurement is within the expected range - The
suspect sensor. The voltage measurement should be 5.0
correct supply voltage is reaching the sensor.
± 0.2 VDC.
Proceed to Test Step 4.
E. Turn the keyswitch to the OFF position.

F. Reconnect the sensor.

Result: A 157-12 diagnostic code is active.

Repair: Replace the fuel rail pressure sensor.

Use the electronic service tool to clear all logged diagnostic codes.
Return the unit to service.

If the fault is still present, contact the Dealer Solutions Network (DSN).
4. Check the Type of Diagnostic Code that is Active
Result: A 411-2 diagnostic code is active.
A. Turn the keyswitch to the ON position. Wait at least 10
seconds for activation of the diagnostic codes. Diagnostic Proceed to Test Step 5.
codes
B. Use the electronic service tool to check for active Result: An XXXX-3 diagnostic code is active for one or more of the
diagnostic codes. Record all active diagnostic codes. active sensors.

Proceed to Test Step 7.

Result: An XXXX-4 diagnostic code is active for one or more of the

active sensors.

Proceed to Test Step 6.

Result: The NRS cooler has excessive fouling.

Replace the NRS cooler. Refer to Disassembly and Assembly, Exhaust

5. Diagnose a 411-2 Code Cooler (NRS) - Remove and Install.

A. Remove the exhaust inlet pipe and the exhaust outlet Verify that the problem is resolved.
pipe from the NRS cooler. Refer to Disassembly and
Assembly, Exhaust Cooler (NRS) - Remove and Install. If the fault is still present, contact the Dealer Solutions Network (DSN).
Short
B. Inspect the inlet port and the outlet port of the NRS created Result: The NRS cooler does not have excessive fouling.
cooler for excessive fouling with condensate and/or soot.
Install a replacement NRS differential pressure sensor. Refer to
Note: A light coating of soot is normal. There must be no Disassembly and Assembly, Pressure Sensor (Cooled Exhaust Gas) -
evidence of wet or shiny condensate fouling or excessive Remove and Install.
soot deposits that cover most of the internal tubes.
Verify that the problem is resolved.

If the fault is still present, contact the Dealer Solutions Network (DSN).

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Result: A -4 diagnostic code was active before disconnecting the

sensor. A -3 diagnostic code became active after disconnecting the
6. Create An Open Circuit at the Sensor Connector
sensor. The sensor is faulty.
A. Turn the keyswitch to the OFF position.
Repair: Temporarily connect a new sensor to the harness, but do not
install the new sensor in the engine. Use the electronic service tool to
B. Disconnect the connector for the sensor with the -4
verify that the repair eliminates the fault and then permanently install the
diagnostic code. Diagnostic
new sensor.
codes
C. Turn the keyswitch to the ON position. Wait for at least
Use the electronic service tool to clear all logged diagnostic codes and
10 seconds for activation of the diagnostic codes.
verify that the repair eliminates the fault.
D. Use the electronic service tool to check the "Active
Result: The -4 diagnostic code is still active.
Diagnostic Code" screen. Check for a -3 diagnostic code.
Proceed to Test Step 8.

7. Create a Short Circuit at the Sensor Connector

A. Turn the keyswitch to the OFF position.

Result: A -3 diagnostic code was active before installing the jumper. A
-4 diagnostic code became active with the jumper installed. The sensor
B. Disconnect the connector for the suspect sensor.
may be faulty.
C. Fabricate a jumper wire that is 150 mm (6 inch) long.
Repair: Temporarily connect a new sensor to the harness, but do not
Crimp a terminal to both ends of the wire.
install the new sensor in the engine. Use the electronic service tool to
verify that the repair eliminates the fault and then permanently install the
D. Use the jumper to connect the sensor signal terminal to
new sensor.
the sensor ground terminal on the harness connector for Diagnostic
the suspect sensor. codes
Use the electronic service tool to clear all logged diagnostic codes and
verify that the repair eliminates the fault.
E. Turn the keyswitch to the ON position. Do not start the
engine.
Result: The -3 diagnostic code remains active when the jumper is
installed.
F. Access the "Active Diagnostic Codes" screen on the
electronic service tool and check for an active -4
Proceed to Test Step 8.
diagnostic code for the suspect sensor.

G. Remove the jumper. Reconnect the sensor.

Result: The wiring failed the Wiggle Test.

There is a problem with the wiring. Repair the wiring or replace the
8. Perform the Wiggle Test
wiring.
Carefully following this procedure is the best way to
Verify that the problem is resolved.
identify the root cause of an intermittent problem.
STOP
A. Turn the keyswitch to the ON position.
Result: The wiring passed the Wiggle Test.
B. Use the electronic service tool to run the "Wiggle Test".
The problem may be intermittent. Inspect the wiring. Refer to
C. Slowly wiggle the wiring and the connectors between
Test Troubleshooting, "Electrical Connectors - Inspect".
the P2 connector and the sensor. Pay particular attention
passed
to the wiring near each connector. Be sure to wiggle all
If the wiring looks OK, perform the following procedure.
the wiring.
As you wiggle the wiring look for these problems.
1. Turn the keyswitch to the OFF position.
1. Loose connectors or damaged connectors
2. Disconnect the connectors. Carefully inspect the terminals for proper
2. Moisture on the connectors or the wiring
installation. Make sure that each terminal is clean and dry.
3. Damaged that is caused by excessive heat
3. Insert a pin into each socket. Verify that each socket grips the pin
4. Damage that is caused by chafing
firmly. Repair any problems.
5. Improper routing of wiring
4. Connect all connectors.
6. Damaged insulation
5. Verify that the problem is resolved.
6. Return the unit to service.
STOP

Table 2

PPI-000740CA
2022/09/30
18:45:34-04:00
i07729674
© 2022 Caterpillar Inc.
Caterpillar:
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