PICANTO(SA) > 2010 > D 1.
1 TCI-U > Steering > MDPS > C1604 EPS Module(pre-charge
circuit) Malfunction
C1604 EPS Module(pre-charge circuit) Malfunction > General Information
Component Location
General Description
EPS CM measures operating torque using torque sensor when driver operates steering wheel. The EPS CM controls the current of
EPS motor in proportion to vehicle speed and operating torque of steering wheel. EPS CM, at times, supplies or cuts off current (as
determined by engine control relay fail safe relay inside EPS CM) to EPS motor operating source and system source.
DTC Description
This DTC is related to general error inside EPS CM. If this DTC is set, check unstable power or excessive surge influx by faulty
power supply and chassis ground.
DTC Detecting Condition
Fail Safe
Detecting Diagnostic
Threshold Value Fail Restoration Possible cause
Condition ime Motor relay
lamp condition
Fail safe relay
Before Fail safe
contact voltage < 1sec OFF OFF ON Power "OFF" ● Pre-charge circuit error
relay operating
2V
17.5V > Fail safe Booster voltage <
Booster V ≥
relay contact Fail safe relay 2sec OFF ON ON ● Booster circuit error
relay contact V
voltage > 9V contact voltage
System power Motor terminal > ● Motor terminal V motor I/F
0.2sec OFF OFF ON Power "OFF"
"ON" 23V or < -3V error
Fail safe relay
contact voltage > Interlock circuit
0.2sec OFF OFF ON Power "OFF" ● Interlock circuit error
8V locked permit
Fail safe relay [torpue sensor
contact voltage > main I/F input - 0.2sec OFF OFF ON Power "OFF" ● torque sensor main I/F error
7.5V output] > 2.5Nm
Detected
System power Control
temperature < - 0.2sec ON OFF Power "OFF" ● thermis- tor error
"ON" 60°C
40°C
Initial
System power EEPROM read
Instantly value ON OFF Power "OFF" ●EEPROM
"ON" error
control
C1604 EPS Module(pre-charge circuit) Malfunction > Inspection/Repair > W/Harness Inspection
Terminal and Connector Inspection
1. Many malfunctions in the electrical system are caused by poor harness and terminals.
Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2. Thoroughly check all connectors (and connections) for looseness, bending, corrosion, contamination, deterioration, and/or
damage.
3. Has a problem been found?
▶ Repair as necessary and then go to "Verification of Vehicle Repair" procedure.
▶ Go to "Power Circuit Inspection" procedure.
Power Supply Circuit Inspection
1. Ignition "OFF".
2. Connect Scantool to Data Link Connector(DLC) and start engine.
3. Select "SCOPEMETER FUNCTION"on scantool and accelerate engine.
4. Measure output signal between terminal "1"of EPS CM harness connector and chassis ground with switching (A/C,headlight etc.).
1) Specification : Surge always must not happen when turn IG key ON, OFF with turn the electricity device ON, OFF.
5. Is the resistance measured within specifications?
▶ Go to "Ground Circuit Inspection" procedure.
▶ Check for contact resistance in connections or open in power harness.
Repair as necessary and then go to "Verification of Vehicle Repair" procedure.
Ground Circuit inspection
1. Check for open in ground harness
(1) Ignition "OFF".
(2) Disconnect EPS CM connector.
(3) Measure resistance between terminal "2"of EPS CM harness connector and chassis ground.
1) Specification : Approx. 0 Ω
(4) Is the resistance measured within specifications?
▶ Go to "Check for earthing in ground harness" as below.
▶ Check for open or contact resistance in ground harness.
Repair as necessary and then go to "Verification of Vehicle Repair" procedure.
2. Check for earthing in ground harness
(1) Ignition "OFF".
(2) Connect Scantool to Data Link Connector(DLC) and start engine.
(3) Select "SCOPEMETER FUNCTION"on scantool and accelerate engine.
(4) Measure output signal between terminal "2"of EPS CM harness connector and chassis ground with switching (A/C,headlight
etc).
1) Specification : Surge always must not happen when turn IG key ON, OFF with turn the electricity device ON, OFF.
(5) Is the output signal within specifications?
▶ Go to "Component Inspection " procedure.
▶ Check for open or poor earthing in ground harness.
Repair as necessary and then go to "Verification of Vehicle Repair" procedure.
C1604 EPS Module(pre-charge circuit) Malfunction > Inspection/Repair > Component Inspection
Component Inspection
1. Connect scantool and select "Diagnostic Trouble Codes(DTCs)" mode.
2. Clear DTC.
3. Drive the vehicle within DTC Enable conditions in General information.
4. Are any DTCs present ?
▶ Check EPS CM for damage or sticking by the naked eye. Substitute with a known-good EPS CM and check for proper
operation.
If the problem is corrected, replace EPS CM and then go to "Verification of vehicle Repair" procedure.
▶ Substitute with a known-good EPS CM and check for proper operation.
If the problem is corrected, replace EPS CM and then go to "Verification of Vehicle Repair" procedure.
C1604 EPS Module(pre-charge circuit) Malfunction > Verification of Vehicle Repair
Verification of Vehicle Repair
After a repair, it is essential to verify that the fault has been corrected.
1. Connect scantool and select "Diagnostic Trouble Codes(DTCs)" mode.
2. Clear DTC.
3. Operate the vehicle within DTC Enable conditions in General information.
4. Are any DTCs present ?
▶ Go to the applicable troubleshooting procedure.
▶ System performing to specification at this time.
