DTC P0403 [L3]


DTC P0403	EGR valve (stepper motor) circuit malfunction
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


STEP	INSPECTION		ACTION
1	PERFORM DTC CONFIRMATION PROCEDURE • Perform DTC CONFIRMATION PROCEDURE. (See DTC CONFIRMATION PROCEDURE [L3].) • Is same DTC present?	Yes	Go to the next step.
1		No	Intermittent concern exists. Go to INTERMITTENT CONCERN TROUBLESHOOTING procedure. (See INTERMITTENT CONCERN TROUBLESHOOTING [L3].)
2	INSPECT POOR CONNECTION OF EGR VALVE • 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 9.
2		No	Go to the next step.
3	INSPECT POWER CIRCUIT FOR OPEN CIRCUIT • Turn the ignition switch to the ON position (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 the voltage B+?	Yes	Go to the next step.
3		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 normal?	Yes	Go to the next step.
4		No	Replace EGR valve, then go to Step 9.
5	INSPECT FOR CONTROL CIRCUIT FOR SHORT TO GROUND • Turn the ignition switch off. • Inspect for 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.
5		No	Go to the next step.
6	INSPECT FOR CONTROL CIRCUIT FOR SHORT TO POWER • Turn the ignition switch to the ON position (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 the voltage B+?	Yes	Repair or replace harness for short to power supply, then go to Step 9.
6		No	Go to the next step.
7	INSPECT POOR CONNECTION OF PCM • Turn the ignition switch off. • Disconnect PCM 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.
7		No	Go to the next step.
8	INSPECT CONTROL CIRCUIT FOR OPEN CIRCUIT • Remove PCM with PCM connector connected. • Inspect for 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 the next step.
8		No	Repair or replace harness for open circuit then go to the 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 the next step. (See PCM REMOVAL/INSTALLATION [L3].)
9		No	Go to the next step.
10	VERIFY AFTER REPAIR PROCEDURE • Perform "After Repair Procedure". (See AFTER REPAIR PROCEDURE [L3].) • Is there any DTC present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [L3].)
10		No	Troubleshooting completed.