LEMON Manuals: Even more car manuals for everyone
Home >> Pontiac >> 2001 >> Aztek Base, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls Self-Diagnostics >> Diagnostic Tests >> DTC P0481: Cooling Fan Relay No. 2 Control Circuit >> Diagnostic Procedures

Diagnostic Procedures

  1. Perform engine cooling diagnostic system check. See appropriate ENGINE COOLING article in ENGINE, CLUTCHES & DRIVE AXLES. Repair as necessary. After performing engine cooling diagnostic system check, go to next step.
  2. Turn ignition on, with engine off. Using scan tool, command high speed fan on and off. If cooling fan relay and cooling fan 2 relays turns on and off with each command, see DIAGNOSTIC AIDS . If relays does not turn on and off, go to next step.
  3. Turn ignition off. Remove cooling fan 2 relay (located in underhood fuse/relay block). Turn ignition on, with engine off. Using a test light connected to ground, probe cooling fan relay 2 battery voltage circuit. If test light illuminates, go to next step. If test light does not illuminate, go to step  8.
  4. Connect test light between high speed cooling fan 2 control circuit and battery voltage circuit in fuse/relay block. Using scan tool, command high speed fans on and off. If test light turns on and off with each command, go to step  9. If test light does not turn on and off with each command, go to next step.
  5. If test light remains on with each command, go to step  7. If test light does not remain on with each command, go to next step.
  6. Turn ignition off. Check cooling fan relay and high speed cooling fan 2 relay control circuit (Dark Blue wire) to PCM harness connector C1 terminal No. 5 for short to voltage or open circuit. See Figure. Repair as necessary. After repairs, go to step  12. If circuit is okay, go to step  9.
  7. Turn ignition off. Check cooling fan relay and high speed cooling fan 2 relay control circuit (Dark Blue wire) for short to ground. Repair as necessary. After repairs, go to step  12. If circuit is okay, go to step  9.
  8. Turn ignition off. Check cooling fan relay and cooling fan 2 relay battery voltage circuit in fuse/relay block for open or short to ground. Repair as necessary. After repairs, go to step  12. If circuit is okay, go to step  10.
  9. Turn ignition off. Check for poor connections at PCM harness connector. Repair as necessary. After repairs, go to step  12. If connections are okay, go to step  11.
  10. Repair cooling fan motor supply voltage circuit (Light Blue wire) for short to ground. After repairs, go to step  12.
  11. Replace PCM. Perform PCM relearn procedure. See POWERTRAIN CONTROL MODULE  under PROGRAMMING. After replacing PCM, go to next step.
  12. Turn ignition on, with engine off. Using scan tool, clear DTCs. Operate vehicle within the conditions for running this DTC. See CODE ENABLE CRITERIA . If DTC resets, go to step  2. If DTC does not reset, system is okay.
scientia non olet · About LEMON Manuals