DTC P0403

DTC P0403	EGR valve (stepping motor) circuit problem
DETECTION CONDITION	The PCM monitors the EGR valve control signal voltage and current. If the following conditions are met, the PCM determines that there is the EGR control circuit problem. The PCM turns the EGR valve off, but the voltage of the EGR valve control signal remains low. The PCM turns the EGR valve on, but the current of the EGR valve control signal remains high. Diagnostic support note This is a continuous monitor (CCM). The MIL illuminates if the 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 the PCM detects the above malfunction condition during the first drive cycle. FREEZE FRAME DATA (Mode 2/Mode 12) is available. The DTC is stored in the PCM memory.
POSSIBLE CAUSE	EGR valve connector or terminals malfunction Open circuit or short to ground in EGR valve power supply circuits Short to ground in wiring harness between main relay and EGR valve terminal C Short to ground in wiring harness between main relay and EGR valve terminal D EGR valve power supply circuits related fuse malfunction Open circuit in wiring harness between main relay and EGR valve terminal C Open circuit in wiring harness between main relay and EGR valve terminal D EGR valve malfunction Short to ground in wiring harness between EGR valve terminal E and PCM terminal 2K Short to ground in wiring harness between EGR valve terminal A and PCM terminal 2G Short to ground in wiring harness between EGR valve terminal B and PCM terminal 2L Short to ground in wiring harness between EGR valve terminal F and PCM terminal 2H PCM connector or terminals malfunction Short to power supply in wiring harness between EGR valve terminal E and PCM terminal 2K Short to power supply in wiring harness between EGR valve terminal A and PCM terminal 2G Short to power supply in wiring harness between EGR valve terminal B and PCM terminal 2L Short to power supply in wiring harness between EGR valve terminal F and PCM terminal 2H Open circuit in wiring harness between EGR valve terminal E and PCM terminal 2K Open circuit in wiring harness between EGR valve terminal A and PCM terminal 2G Open circuit in wiring harness between EGR valve terminal B and PCM terminal 2L Open circuit in wiring harness between EGR valve terminal F and PCM terminal 2H PCM malfunction

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA (MODE 12) HAS BEEN RECORDED Has the FREEZE FRAME DATA (Mode 12) been recorded?	Yes	Go to the next step.
1		No	Record the FREEZE FRAME DATA (Mode 12) on the repair order, then go to the next step.
2	VERIFY RELATED SERVICE BULLETINS AVAILABILITY Verify related Service Bulletins availability. Is any related Service Bulletins available?	Yes	Perform the repair or diagnosis according to the available Service Bulletins. If the vehicle is not repaired, go to the next step.
2		No	Go to the next step.
3	INSPECT EGR VALVE CONNECTOR AND TERMINALS Turn the ignition switch off. Disconnect the EGR valve connector. Inspect for poor connection (such as damaged/pulled-out pins, and corrosion). Is there any malfunction?	Yes	Repair or replace the connector or terminals, then go to Step 10.
3		No	Go to the next step.
4	INSPECT EGR VALVE POWER SUPPLY CIRCUITS FOR OPEN CIRCUIT OR SHORT TO GROUND EGR valve connector is disconnected. Turn the ignition switch to the ON position (Engine off). Measure the voltage between the following terminals (wiring harness-side) and body ground: EGR valve terminal C EGR valve terminal D Is the voltage B+?	Yes	Go to the next step.
4		No	Inspect the EGR valve power supply circuits related fuse. If the fuse is melt: Repair or replace the wiring harness for a possible short to ground. Replace the fuse. If the fuse is deterioration: Replace the fuse. If the fuse is normal: Repair or replace the wiring harness for a possible open circuit. Go to Step 10.
5	INSPECT EGR VALVE Turn the ignition switch off. Reconnect the EGR valve connector. Inspect the EGR valve. (See EGR VALVE INSPECTION ). Is there any malfunction?	Yes	Replace the EGR valve, then go to Step 10. (See EGR VALVE REMOVAL/INSTALLATION ).
5		No	Go to the next step.
6	INSPECT EGR VALVE CIRCUITS FOR SHORT TO GROUND Disconnect the EGR valve connector. Inspect for continuity between the following terminals (wiring harness-side) and body ground: EGR valve terminal E EGR valve terminal A EGR valve terminal B EGR valve terminal F Is there continuity?	Yes	If the short to ground circuit could be detected: Repair or replace the wiring harness for a possible short to ground. If the short to ground circuit could not be detected: Replace the PCM (short to ground in PCM internal circuit). (See PCM REMOVAL/INSTALLATION ). Go to Step 10.
6		No	Go to the next step.
7	INSPECT PCM CONNECTOR AND TERMINALS Disconnect the PCM connector. Inspect for poor connection (such as damaged/pulled-out pins, and corrosion). Is there any malfunction?	Yes	Repair or replace the connector or terminals, then go to Step 10.
7		No	Go to the next step.
8	INSPECT EGR VALVE CIRCUITS FOR SHORT TO POWER SUPPLY EGR valve and PCM connectors are disconnected. Turn the ignition switch to the ON position (Engine off). Measure the voltage between the following terminals (wiring harness-side) and body ground: EGR valve terminal E EGR valve terminal A EGR valve terminal B EGR valve terminal F Is there any voltage?	Yes	Repair or replace the wiring harness for a possible short to power supply, then go to Step 10.
8		No	Go to the next step.
9	INSPECT EGR VALVE CIRCUITS FOR OPEN CIRCUIT EGR valve and PCM connectors are disconnected. Turn the ignition switch off. Inspect for continuity between the following terminals (wiring harness-side): EGR valve terminal E and PCM terminal 2K EGR valve terminal A and PCM terminal 2G EGR valve terminal B and PCM terminal 2L EGR valve terminal F and PCM terminal 2H Is there continuity?	Yes	Go to the next step.
9		No	Repair or replace the wiring harness for a possible open circuit, then go to the next step.
10	VERIFY TROUBLESHOOTING OF DTC P0403 COMPLETED Make sure to reconnect all disconnected connectors. Clear the DTC from the PCM memory using the M-MDS. Perform the KOEO or KOER self test. (See KOEO/KOER SELF TEST ). Is the PENDING CODE for this DTC present?	Yes	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION ).
10		No	Go to the next step.
11	VERIFY AFTER REPAIR PROCEDURE Perform the "AFTER REPAIR PROCEDURE". (See AFTER REPAIR PROCEDURE ). Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE ).
11		No	DTC troubleshooting completed.