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Home >> Pontiac >> 2002 >> Aztek AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls Self-Diagnostics >> Diagnostic Tests >> DTC P0650: Mil Control Circuit >> Diagnostic Procedures
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Diagnostic Procedures

  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. Turn ON the ignition, with the engine OFF. Command the MIL ON and OFF using the scan tool. Does the MIL turn ON and OFF when commanded? If yes, see DIAGNOSTIC AIDS . If no, go to next step.
  3. Turn OFF the ignition. Disconnect the PCM. Turn ON the ignition. Is the lamp OFF? If yes, go to next step. If no, go to step  5.
  4. Probe the lamp control circuit in the PCM harness connector with a fused jumper wire connected to ground. Is the lamp ON? If yes, go to step  6. If no, go to step  7.
  5. Repair the short to ground in the lamp control circuit. After repairs, go to step  9.
  6. Inspect for poor connections at the PCM. If you find a poor connection, repair the terminal as necessary. Did you find and correct the condition? If yes, go to step  9. If no, go to step  8.
  7. Test for the following conditions:
    • Open ignition positive voltage to the MIL bulb.
    • Control circuit open or shorted to battery positive voltage.

    Repair as necessary. After repairs, go to step  9.

  8. Replace the PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. Reprogram PCM. See POWERTRAIN CONTROL MODULE  under PROGRAMMING. After repairs, go to next step.
  9. Clear the DTCs with a scan tool. 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.
  10. 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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