LEMON Manuals: Even more car manuals for everyone
Home >> GMC >> 2003 >> Safari Van Cargo, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 123 (Engine Controls - Self-Diagnostics - 4.0L) >> Diagnostic Tests >> DTC P0403: EGR Solenoid Control Circuit >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different car, the 2002 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.
  1. Did you perform the Diagnostic System Check - Engine Controls? If yes, go to next step. If no, go to DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS  under SELF-DIAGNOSTIC SYSTEM.
  2. Turn ignition on, with engine off. Using scan tool, command EGR from zero to 100 percent. Does the EGR Position Sensor remain close to the Desired EGR Position at all Commanded positions? If yes, go to next step. If no, go to step  4.
  3. Using scan tool, observe and record FREEZE FRAME/FAILURE RECORDS data for this DTC. Turn ignition off for 30 seconds. Start engine. Operate vehicle within conditions for running the DTC or as close to recorded FREEZE FRAME/FAILURE RECORDS data as possible. See CONDITIONS FOR RUNNING DTC . Does the DTC fail this ignition cycle? If yes, go to next step. If no, fault may be intermittent. See INTERMITTENT CONDITIONS  under SELF-DIAGNOSTIC SYSTEM.
  4. Turn ignition off. Disconnect EGR harness connector. Turn ignition on, with engine off. Probe EGR solenoid high control circuit with a test lamp connected to a good ground. With scan tool, command EGR between 0 percent and 10 percent. Does test lamp turn ON and OFF with each command? If yes, go to next step. If no, go to step  6.
  5. Connect a test lamp between the high control circuit of solenoid and low control circuit of solenoid harness connector. With scan tool, command EGR between 0 and 10 percent. Does test lamp turn ON and OFF with each command? If yes, go to step  10. If no, go to step  9.
  6. Does the test lamp remain illuminated with each command? If yes, go to step  8. If no, go to next step.
  7. Test EGR solenoid high control circuit for a short to ground or an open. Did you find and correct the condition? If yes, go to step  14. If no, go to step  11.
  8. Test the EGR solenoid high control circuit for a short to voltage. Did you find and correct the condition? If yes, go to step  14. If no, go to step  11.
  9. Test the EGR solenoid low control circuit for an open or high resistance. Did you find and correct the condition? If yes, go to step  14. If no, go to step  11.
  10. Check for poor connections at EGR valve connector. Did you find and correct the condition? If yes, go to step  14. If no, go to step  12.
  11. Check for poor connections at PCM connectors. Did you find and correct the condition? If yes, go to step  14. If no, go to step  13.
  12. Replace EGR valve. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. After repairs, go to step  14.
  13. Replace the PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. Reprogram PCM. See POWERTRAIN CONTROL MODULE  under PROGRAMMING. After repairs, go to next step.
  14. Use the scan tool in order to clear the DTCs. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running DTC. Does the DTC run and pass? If yes, go to next step. If no, go to step  2.
  15. With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? If yes, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, system is okay.
scientia non olet · About LEMON Manuals