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Home >> Chevrolet >> 2000 >> Venture Plus >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls Self-Diagnostics >> Diagnostic Tests >> DTC P0418: Secondary Air Injection Pump Relay Control Circuit >> Diagnostic Procedures
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Diagnostic Procedures

  1. Perform On-Board Diagnostic (OBD) system check. See ON-BOARD DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing OBD system check, go to next step.
  2. Turn ignition on, with engine off. Using scan tool, command AIR pump relay and solenoid on and off. If solenoid turns on and off with each command, see DIAGNOSTIC AIDS . If solenoid does not turn on and off with each command, go to next step.
  3. Turn ignition off. Disconnect AIR relay. Turn ignition on, with engine off. Using a test light connected to ground, probe relay coil feed circuit. If test light illuminates, go to next step. If test light does not illuminate, go to step  10.
  4. Connect test light between relay control and coil feed circuit. Using scan tool, command AIR pump relay and 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 on with each command, go to step  7. If test light does not remain on with each command, go to next step.
  6. Check relay control circuit for short to voltage or an open circuit. Repair as necessary. After repairs, go to step  13. If circuit is okay, go to step  9.
  7. Check relay control circuit for short to ground. Repair as necessary. After repairs, go to step  13. If circuit is okay, go to step  9.
  8. Check for poor connections at relay. Repair as necessary. After repairs, go to step  13. If connections are okay, go to step  11.
  9. Check for poor connections at PCM. Repair as necessary. After repairs, go to step  13. If connections are okay, go to step  12.
  10. Repair relay feed circuit. After repairs, go to step  13.
  11. Replace relay. After replacing relay, go to step  13.
  12. Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
  13. Using scan tool, clear DTCs. Operate vehicle within conditions for setting this DTC. Recheck for DTCs. If this DTC resets, go to step  2. If this DTC does not reset, system is okay.
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