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Home › Oldsmobile › 2001 › Intrigue GLS › Repair and Diagnosis › Engine Performance › System › Engine Controls - Self-Diagnostics › Diagnostic Tests › DTC P0418: Secondary Air Injection Pump Relay Control Circuit › Diagnostic Procedures

Diagnostic Procedures

  1. If powertrain diagnostic system check has already been performed, go to next step. If powertrain diagnostic system check has not been performed, go to POWERTRAIN DIAGNOSTIC SYSTEM CHECK  under DIAGNOSTIC SYSTEM CHECKS.
  2. Turn ignition on. Using scan tool, command AIR pump relay on and off. If AIR pump relay turns on and off with each command, no problem is indicated. Fault may be intermittent. See INTERMITTENTS in appropriate TROUBLE SHOOTING - NO CODES article. If AIR pump relay does not turn on and off with each command, go to next step.
  3. Turn ignition off. Disconnect AIR pump relay. AIR pump relay is located in underhood accessory fuse block (smallest fuse block), next to underhood fuse block. Underhood fuse block is mounted to strut tower on right side of engine compartment. Turn ignition on. Using a test light connected to ground, probe Pink wire at AIR pump relay harness connector in underhood accessory fuse block. See WIRING DIAGRAMS article. If test light illuminates, go to next step. If test light does not illuminate, go to step  10.
  4. Connect a test light between Pink and Brown wires at AIR pump relay harness connector in underhood accessory fuse block. Using scan tool, command AIR pump and AIR solenoid on and off. If test light turns on and off with each command, go to step  8. If test light does not turn on and off with each command, go to next step.
  5. If test light remains illuminated with each command, go to step  7. If test light does not remain illuminated with each command, go to next step.
  6. Turn ignition off. Disconnect PCM connectors. PCM is located in left front corner of engine compartment, inside air filter housing. Check for an open or short to voltage in Brown wire between AIR pump relay harness connector in underhood accessory fuse block and terminal No. 75 at PCM C2 harness connector. See Figure. If any problems are found, repair as necessary. After repairs, go to step  13. If no problems are found, go to step  9.
  7. Turn ignition off. Disconnect PCM connectors. PCM is located in left front corner of engine compartment, inside air filter housing. Using a test light connected to positive battery voltage, probe terminal No. 75 (Brown wire) at PCM C2 harness connector. If test light does not illuminate, go to step  9. If test light illuminates, repair short to ground in Brown wire between PCM and AIR pump relay. After repairs, reconnect all components. Using scan tool, command AIR pump and AIR solenoid on and off. If AIR pump does not operate, replace AIR pump. After repairs, go to step  13.
  8. Check for poor connections at AIR pump relay connector. Repair connector as necessary. After repairs, go to step  13. If connector is okay, go to step  11.
  9. Check for poor connections at PCM connectors. Repair connectors as necessary. After repairs, go to step  13. If connectors are okay, go to step  12.
  10. Repair Pink wire between AIR pump relay and fuse No. 30 (ENG EMIS fuse) in underhood fuse block. After repairs, go to step  13.
  11. Replace AIR pump relay. After repairs, go to step  13.
  12. Replace PCM. Program replacement PCM. See PROGRAMMING . After repairs, go to next step.
  13. Turn ignition off. Reconnect all disconnected connectors. Turn ignition on. Using scan tool, clear DTCs. Turn ignition off for 30 seconds. Start engine. Operate vehicle within conditions for running the DTC as specified in code enable criteria. If DTC runs and passes, go to next step. If DTC resets, go to step  2.
  14. Using scan tool, check for any other DTCs that are set. If no other DTCs are set, test is complete. If any other DTCs are set, repair DTCs as necessary. See DIAGNOSTIC TROUBLE CODE DEFINITIONS .
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