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Home >> GMC >> 2003 >> Safari Van Cargo, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 69 (Engine Controls Self-Diagnostics - 4.3L) >> Diagnostic Tests >> DTC P1404: EGR Valve Closed Pintle Position >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different car, the 2002 GMC Savana and 2002 Chevrolet Chevy Express. 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, see DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS  under SELF-DIAGNOSTIC SYSTEM.
  2. Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, command the EGR valve from 0 percent 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. Observe the Freeze Frame/Failure Records data for this DTC. Turn OFF the ignition for 30 seconds. Operate the vehicle within the Conditions for Running DTC or as close to the Freeze Frame/Failure Records data that you observed. Does the DTC fail this ignition cycle? If yes, go to next step. If no, see DIAGNOSTIC AIDS .
  4. Turn OFF the ignition. Disconnect the EGR valve connector. Turn ON the ignition, with the engine OFF. Probe the EGR solenoid high control circuit with a test lamp connected to a good ground. With a scan tool, command the EGR valve between 0-10 percent. Does the test lamp turn ON and OFF with each command? If yes, go to next step. If no, go to step  13.
  5. With a scan tool, observe the EGR position sensor parameter. Does the scan tool indicate that the EGR position sensor is at 0%? If yes, go to next step. If no, go to step  9.
  6. Measure the voltage from the 5-volt reference circuit of the EGR position sensor to the low reference circuit of the EGR position sensor. Does the Digital Multimeter (DMM) display voltage near 5.0 V? If yes, go to next step. If no, go to step  8.
    7. NOTE: If the fuse opens, locate and repair a short to ground in the signal circuit.
  7. Connect a fused jumper between the 5-volt reference circuit of the EGR position sensor and the EGR valve position signal circuit of the EGR position sensor. Does the scan tool indicate that the EGR position sensor is near 100%? If yes, go to step  14. If no, go to step  11.
  8. Measure the voltage from the 5-volt reference circuit of the EGR position sensor to a good ground. Does the DMM display voltage near 5.0 V? If yes, go to step  10. If no, go to step  12.
  9. Test the EGR valve position signal circuit for a short to voltage. Did you find and correct the condition? If yes, go to step  18. If no, go to step  15.
  10. Test the low reference circuit for an open or high resistance. Did you find and correct the condition? If yes, go to step  18. If no, go to step  15.
  11. Test the EGR valve position signal circuit for high resistance or a high resistance short to ground. Did you find and correct the condition? If yes, go to step  18. If no, go to step  15.
  12. Test the 5-volt reference circuit of the EGR position sensor for an open, a short to ground, or a short to voltage. Did you find and correct the condition? If yes, go to step  18. If no, go to step  15.
  13. Test the EGR solenoid high control circuit for a short to voltage. Did you find and correct the condition? If yes, go to step  18. If no, go to step  15.
  14. Inspect for poor connections at the harness connector of the EGR valve. Did you find and correct the condition? If yes, go to step  18. If no, go to step  16.
  15. Inspect for poor connections at the harness connector of the PCM. Did you find and correct the condition? If yes, go to step  18. If no, go to step  17.
  16. Replace the EGR valve. After repairs, go to step  18.
  17. Replace the PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. Reprogram PCM. See POWERTRAIN CONTROL MODULE  under PROGRAMMING. After repairs, go to next step.
  18. Clear the DTCs with a scan tool. Turn OFF the ignition. 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.
  19. Observe the stored information, Capture Info with a scan tool. Does the scan tool display any DTCs that you have not diagnosed? If yes, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, system is okay.
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