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Home >> Mitsubishi >> 2002 >> Lancer ES, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0403: EGR Control Circuit >> Diagnostic Procedure
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Diagnostic Procedure

CAUTION: To prevent damage to scan tool, always turn ignition switch to LOCK position before connecting or disconnecting scan tool.
  1. Using scan tool, check EGR solenoid. Connect scan tool to data link connector. Turn ignition on. Set scan tool to the actuator test mode for item 10: EGR SOLENOID. An operation sound should be heard and vibration should be felt when the EGR solenoid is operated. Turn ignition switch to LOCK position. If solenoid is not operating properly, go to next step. If solenoid is operating properly, malfunction is intermittent.
  2. Check EGR solenoid harness connector for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step  12 .
  3. Disconnect EGR solenoid harness connector. Using a DVOM, measure resistance between EGR solenoid terminals No. 1 and 2. Standard value is 29-35 ohms at 68°F (20°C). If resistance is as specified, go to next step. If resistance is not as specified, replace the EGR solenoid. Then go to step  12 .
  4. Turn ignition on. Measure voltage between EGR solenoid harness connector terminal No. 1 and ground. Battery voltage should be present. Turn ignition switch to LOCK position. If voltage is as specified, go to step  6 . If voltage is not as specified, go to next step.
  5. Check connector B-12X at MFI relay for damage. Repair or replace as necessary. After repairs, go to step  12 . If connector is okay, repair open or shorted circuit in harness between MFI relay connector B-12X terminal No. 4 and EGR solenoid harness connector terminal No. 1. After repairs, go to step  12 .
  6. Do not disconnect ECM harness connector C-121 (M/T) or PCM harness connector C-120 (A/T). Turn ignition on. Measure voltage between ECM or PCM harness connector terminal No. 6 and ground by backprobing. Battery voltage should be present. Turn ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step  9 .
  7. Check ECM harness connector C-121 (M/T) or PCM harness connector C-120 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step  12 .
  8. Check for open or short circuit to ground in harness between EGR solenoid harness connector terminal No. 2 and ECM harness connector C-121 terminal No. 6 (M/T) or PCM harness connector C-120 terminal No. 6 (A/T). If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to step  12 . If wiring harness is not in good condition, repair as necessary. After repairs, go to step  12 .
  9. Check ECM harness connector C-121 (M/T) or PCM harness connector C-120 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step  12 .
  10. Check for harness damage between MFI relay connector B-12X terminal No. 4 and EGR solenoid harness connector terminal No. 1. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to step  12 .
  11. Check for harness damage between EGR solenoid harness connector terminal No. 2 and ECM harness connector C-121 terminal No. 6 (M/T) or PCM harness connector C-120 terminal No. 6 (A/T). If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to next step.
  12. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See OTHER MONITOR  under VERIFYING REPAIRS. Check for DTCs. If DTC P0403 is output, repeat diagnosis. If DTC P0403 is not output, inspection is complete.
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