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Home >> Chevrolet >> 2000 >> Chevy Express G2500, Van Cargo Extended, 6.5 F >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Self-Diagnostics - Diesel >> Diagnostic Tests >> DTC P1643: Wait To Start Light Control Circuit >> Diagnostic Procedures
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Diagnostic Procedures

  1. If OBD system check has been performed, go to next step. If OBD system check has not been performed, see ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM.
  2. Connect scan tool. Turn ignition on. Using scan tool, command glow plug light on and off. If WAIT TO START light illuminates, go to next step. If WAIT TO START light does not illuminate, go to step  4.
  3. DTC is intermittent. If no additional DTCs are set, see DIAGNOSTIC AIDS . If any additional DTCs are set, perform appropriate DTC test.
  4. Turn ignition off. Disconnect PCM harness connector containing WAIT TO START light control circuit. Turn ignition on. If WAIT TO START light does not illuminate, go to next step. If WAIT TO START light illuminates, go to step  7.
  5. Connect fused jumper wire between ground and WAIT TO START light control circuit at PCM harness connector. If WAIT TO START light illuminates, go to next step. If WAIT TO START light does not illuminate, go to step  8.
  6. Check for poor connections at PCM. Repair as necessary. After repairs, go to step  10. If connections are okay, go to step  9.
  7. Check for short to ground in WAIT TO START light control circuit. Repair as necessary. After repairs, go to step  10.
  8. Check WAIT TO START light control circuit for open ignition feed circuit, faulty bulb, or open or short to battery voltage. Repair as necessary. After repairs, go to step  10.
  9. Replace PCM. Perform PCM relearn procedures. See PROGRAMMING . After repairs, go to next step.
  10. Using scan tool, clear DTCs. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, and then enter DTC P1643. Operate vehicle within the conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, go to step  2.
  11. Using scan tool, check for DTCs. If any undiagnosed DTCs are set, perform appropriate DTC test. If no DTCs are set, system is okay.
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