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Home >> Cadillac >> 2000 >> Seville STS >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Self-Diagnostics - 4.6L >> Diagnostic Tests >> DTC P0230: Fuel Pump Relay Control Circuit >> Diagnostic Procedures
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Diagnostic Procedures

  1. Perform On-Board Diagnostic (OBD) system check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing OBD system check, go to next step.
  2. Turn ignition off. Disconnect fuel pump relay harness connector. Turn ignition on, with engine off. Wait about 2 seconds, then check voltage between fuel pump relay control and ground circuits in relay harness connector. If voltage reading is about zero volts, go to step  4. If voltage reading is not about zero volts, go to next step.
  3. Turn ignition off. Disconnect PCM harness connector. Leave fuel pump relay harness connector disconnected. Turn ignition on, with engine off. Check for short to battery voltage in fuel pump relay control circuit. Repair as necessary. After repairs, go to step  12. If circuit is okay, go to step  11.
  4. Connect DVOM between fuel pump relay control and ground circuits at harness connector. Using scan tool, select FUEL PUMP OUTPUT CONTROL function and command fuel pump on. Observe DVOM. If battery voltage is present for about 2 seconds, go to next step. If battery voltage is not present for about 2 seconds, go to step  6.
  5. Check for poor connections in fuel pump relay connector. Repair as necessary. After repairs, go to step  12. If connections are okay, go to step  10.
  6. Leave ignition on, with engine off. Using scan tool, select FUEL PUMP OUTPUT CONTROL function. Connect DVOM between chassis ground and fuel pump relay control circuit at harness connector. Using scan tool, command fuel pump on. Observe DVOM voltage reading. If battery voltage is present for about 2 seconds, go to step  9. If battery voltage is not present for about 2 seconds, go to next step.
  7. Turn ignition off. Disconnect PCM harness connector. Check for open or short to ground in fuel pump relay control circuit. Repair as necessary. After repairs, go to step  12. If circuit is okay, go to next step.
  8. Check for poor connections at PCM. Repair as necessary. After repairs, go to step  12. If connections are okay, go to step  11.
  9. Repair open or poor ground connection in relay ground circuit. After repairs, go to step  12.
  10. Replace fuel pump relay. After replacing relay, go to step  12.
  11. Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
  12. Using scan tool, review and record FAIL RECORDS data. Clear DTCs. Operate vehicle within fail records conditions. Monitor SPECIFIC DTC INFO for this DTC until test runs. If scan tool indicates that this failed this ignition, go to step  2. If scan tool does not indicate that this DTC failed this ignition, system is okay.
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