DTC P0403 [AJ] (VIN: JMZ LW19J7*# 300001-, JM0 LW10J300 300001-301405, JM6 LW10J300 300001-, JM8 LW28J**# 300001-301513)

BME010200400203

DTC P0403

EGR valve (stepper motor) circuit malfunction

DETECTION CONDITION

• The PCM monitors the input voltages from EGR valve control signals. If voltage is below or above specified, PCM determines that the EGR valve circuit has malfunction.
Diagnostic support note
• This is a continuous monitor. (CCM)
• MIL illuminates if PCM detects the above malfunction conditions in two consecutive drive cycles.
• PENDING CODE is available if PCM detects the above malfunction condition during first drive cycle.
• FREEZE FRAME DATA is not available.
• DTC is not stored in the PCM memory.

POSSIBLE CAUSE

• EGR valve malfunction
• Connector or terminal malfunction
• Short to ground circuit in wiring between EGR valve terminal E and PCM terminal 12
• Short to ground circuit in wiring between EGR valve terminal A and PCM terminal 72
• Short to ground circuit in wiring between EGR valve terminal B and PCM terminal 46
• Short to ground circuit in wiring between EGR valve terminal F and PCM terminal 56
• Open circuit in wiring between EGR valve terminal E and PCM terminal 12
• Open circuit in wiring between EGR valve terminal A and PCM terminal 72
• Open circuit in wiring between EGR valve terminal B and PCM terminal 46
• Open circuit in wiring between EGR valve terminal F and PCM terminal 56
• Open circuit in wiring between main relay terminal D and EGR valve terminal C
• Open circuit in wiring between main relay terminal D and EGR valve terminal D
• PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION

1
VERIFY RELATED SERVICE INFORMATION AVAILABILITY
• Check for related Service Information availability.
• Is any related Service Information available?
Yes
Perform repair or diagnosis according to available Service Information.
• If vehicle is not repaired, go to the next step.
No
Go to the next step.
2
CLASSIFY INTERMITTENT CONCERN OR CONTINUOUS CONCERN
• Turn the ignition switch off, then to the ON position (Engine off).
• Is same DTC present?
Yes
Go to the next step.
No
Intermittent concern exists. Go to INTERMITTENT CONCERNS TROUBLESHOOTING procedure.
3
INSPECT EGR VALVE FOR POOR CONNECTION
• Turn the ignition switch off.
• Disconnect EGR valve connector.
• Inspect for poor connection (damaged, pulled-out terminals, corrosion, etc.).
• Is there any malfunction?
Yes
Repair or replace terminals and/or connector, then go to Step 8.
No
Go to the next step.
4
INSPECT POWER CIRCUIT FOR OPEN CIRCUIT
•  Turn the ignition switch to the ON position (Engine off).
•  Measure the following EGR valve power circuit terminal voltage.
- EGR valve terminal C and body ground
- EGR valve terminal D and body ground
•  Is the voltage B+?
Yes
Go to the next step.
No
Repair or replace the wiring harness for open circuit then go to Step 8.
5
INSPECT EGR VALVE
• Perform EGR valve inspection.
•  Is the EGR valve normal?
Yes
Go to the next step.
No
Replace the EGR valve, then go to Step 8.
6
INSPECT FOR CONTROL CIRCUIT FOR SHORT TO GROUND
• Inspect for continuity at the following EGR valve control circuit.
- EGR valve terminal E and body ground
- EGR valve terminal A and body ground
- EGR valve terminal B and body ground
- EGR valve terminal F and body ground
• Is there continuity?
Yes
Repair or replace the wiring harness for short to ground, then go to Step 8.
No
Go to the next step.
7
INSPECT CONTROL CIRCUIT FOR OPEN CIRCUIT
•  Disconnect the PCM connector.
• Inspect continuity at the following EGR control circuit.
- EGR valve terminal E and PCM terminal 12
- EGR valve terminal A and PCM terminal 72
- EGR valve terminal B and PCM terminal 46
- EGR valve terminal F and PCM terminal 56
• Is there continuity?
Yes
Go to the next step.
No
Repair or replace the wiring harness for open circuit then go to the next step.
8
VERIFY TROUBLESHOOTING OF DTC P0403 COMPLETED
• Make sure to reconnect all disconnected connectors.
• Turn the ignition switch off, then to the ON position (Engine off).
• Is the same DTC present?
Yes
Replace the PCM, then go to the next step.
No
Go to the next step.
9
VERIFY AFTER REPAIR PROCEDURE
• Perform "After Repair Procedure".
• Is there any DTC present?
Yes
Go to the applicable DTC inspection.
No
Troubleshooting completed.