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DTC P0403 [L3]

BME010200400W01

DTC P0403 | EGR valve (stepper motor) circuit malfunction
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DETECTION CONDITION | • PCM monitors input voltage from EGR valve. If voltage at PCM terminals 4E, 4H, 4K and/or 4N remain low or high, PCM determines that 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 or in one drive cycle while the DTC for the same malfunction has been stored in the PCM.
• PENDING CODE is available if PCM detects the above malfunction condition during first drive cycle.
• FREEZE FRAME DATA is available.
• DTC is stored in the PCM memory.
POSSIBLE CAUSE | • EGR valve malfunction • Connector or terminal malfunction • Short to power circuit in wiring between EGR valve terminal E and PCM terminal 4E • Short to power circuit in wiring between EGR valve terminal A and PCM terminal 4H • Short to power circuit in wiring between EGR valve terminal B and PCM terminal 4K
• Short to power circuit in wiring between EGR valve terminal F and PCM terminal 4N
• Short to ground circuit in wiring between EGR valve terminal E and PCM terminal 4E
• Short to ground circuit in wiring between EGR valve terminal A and PCM terminal 4H
• Short to ground circuit in wiring between EGR valve terminal B and PCM terminal 4K
• Short to ground circuit in wiring between EGR valve terminal F and PCM terminal 4N
• Open circuit in wiring between EGR valve terminal E and PCM terminal 4E
• Open circuit in wiring between EGR valve terminal A and PCM terminal 4H
• Open circuit in wiring between EGR valve terminal B and PCM terminal 4K
• Open circuit in wiring between EGR valve terminal F and PCM terminal 4N
• Open circuit in wiring between main relay and EGR valve terminal C
• Open circuit in wiring between main relay and EGR valve terminal D
• PCM malfunction

Diagnostic procedure

STEP | INSPECTION | ACTION
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1 | PERFORM DTC CONFIRMATION PROCEDURE • Perform DTC CONFIRMATION PROCEDURE. (See DTC CONFIRMATION PROCEDURE [L3].) • Is same DTC present? | Yes | Go to next step.
No | Intermittent concern exists. Go to INTERMITTENT CONCERN TROUBLESHOOTING procedure. (See INTERMITTENT CONCERN TROUBLESHOOTING [L3].)
2 | INSPECT POOR CONNECTION OF EGR VALVE • Turn ignition key to 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 9.
No | Go to next step.
3 | INSPECT POWER CIRCUIT FOR OPEN CIRCUIT • Turn ignition key to ON (Engine OFF). • Measure following EGR valve power circuit terminal voltage.

  - EGR valve terminal C and body ground
  - EGR valve terminal D and body ground

• Is voltage B+?
Yes
Go to next step.
No | Repair or replace harness for open circuit then go to Step 9.
4 | INSPECT EGR VALVE • Perform EGR valve inspection. (See EGR VALVE INSPECTION [L3].) • Is EGR valve okay? | Yes | Go to next step.
No | Replace EGR valve, then go to Step 9.
5 | INSPECT FOR CONTROL CIRCUIT FOR SHORT TO GROUND • Turn ignition key to OFF. • Inspect continuity following EGR 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 harness for short to ground, then go to Step 9.
No | Go to next step.
6 | INSPECT FOR CONTROL CIRCUIT FOR SHORT TO POWER • Turn ignition switch key to ON (Engine OFF). • Measure voltage 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 voltage B+?
Yes
Repair or replace harness for short to power, then go to Step 9.
No | Go to next step.
7 | INSPECT POOR CONNECTION OF PCM • Turn ignition key to OFF. • Disconnect PCM connector. • Check 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 9.
No | Go to next step.
8 | INSPECT CONTROL CIRCUIT FOR OPEN CIRCUIT • Remove PCM with PCM connector connected. • Inspect continuity following EGR control circuit.

  - EGR valve terminal E and PCM terminal 4E
  - EGR valve terminal A and PCM terminal 4H
  - EGR valve terminal B and PCM terminal 4K
  - EGR valve terminal F and PCM terminal 4N

• Is there continuity?
Yes
Go to next step.
No | Repair or replace harness for open circuit then go to next step.
9 | VERIFY TROUBLESHOOTING OF DTC P0403 COMPLETED • Make sure to reconnect all disconnected connectors. • Clear DTC from PCM memory using WDS or equivalent. • Perform KOEO/KOER self-test. (See KOEO/KOER SELF-TEST PROCEDURE [L3].)
• Is same DTC present?
Yes
Replace PCM, then go to next step.
(See PCM REMOVAL/INSTALLATION [L3].)
No | Go to next step.
10 | VERIFY AFTER REPAIR PROCEDURE • Perform "After Repair Procedure". (See AFTER REPAIR PROCEDURE [L3].) • Is there any DTC present? | Yes | Go to applicable DTC troubleshooting. (See DTC TABLE [L3].)
No | Troubleshooting completed.