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Home >> Buick >> 2002 >> Century Custom >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Self-Diagnostics - 3.1L Engine >> Diagnostic Tests >> DTC P0130: Ho2S Circuit (Sensor 1) >> Diagnostic Procedures

Diagnostic Procedures

  1. Perform diagnostic system check - engine controls. See DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS  under SELF-DIAGNOSTIC SYSTEM. After performing diagnostic system check - engine controls, go to next step.
  2. Allow the engine to idle at operating temperature. Observe the HO2S 1 voltage parameter with a scan tool. Clear the DTC and record the Freeze/Frame Failure Records data if the HO2S 1 voltage is fixed at bias voltage. Does the HO2S 1 voltage fluctuate rapidly at greater than 350 millivolts and less than 550 millivolts? If yes, go to next step. If no, go to step  4.
  3. Observe the Freeze Frame/Failure Records data for this DTC. Turn ignition off for 30 seconds. Start engine. Operate the vehicle within the Conditions for Running the DTC or as close to the Freeze Frame/Failure Records data that you observed. See CONDITIONS FOR RUNNING DTC . Does the DTC fail this ignition? If yes, go to next step. If no, see INTERMITTENT CONDITIONS  under SELF-DIAGNOSTIC SYSTEM.
  4. Turn ignition off. Disconnect the HO2S 1 connector. Turn ignition on, with engine off. Measure the voltage from the high signal circuit of the HO2S 1 harness connector, on the engine side, to a good ground with a Digital Multimeter (DMM). Is the HO2S voltage within 0.425-0.500 volt? If yes, go to next step. If no, go to step  6.
  5. Turn ignition off. Connect a 3-amp fused jumper wire between the HO2S 1 harness connector high signal and low signal circuits. Turn ignition on, with engine off. Observe the HO2S 1 voltage on the scan tool. Does the scan tool display less than 25 millivolts? If yes, go to step  8. If no, go to next step.
  6. Turn ignition off. Disconnect both PCM connectors. Measure resistance of each of the following circuits with a DMM: HO2S 1 high signal circuit between HO2S connector and PCM connector, HO2S 1 low signal circuit between HO2S connector PCM connector, and HO2S 1 low reference circuit between terminal C1-29 and terminal C2-80 of PCM connectors. Is resistance of each circuit less than 5 ohms? If yes, go to step  11. If no, go to next step.
  7. Repair the circuit that measured a high resistance or an open. After repairs, go to step  14.
  8. Remove the jumpers from the HO2S 1 terminals. Connect a test light between the HO2S 1 ignition voltage circuit and the HO2S 1 heater low control circuit terminals, on the engine harness side. Start engine. Does the test light illuminate? If yes, go to next step. If no, go to DTC P0135: HO2S HEATER PERFORMANCE .
    NOTE: Contamination of the oxygen sensor can result from the use of an inappropriate RTV sealant (not oxygen sensor safe) or excessive engine coolant or oil consumption.
  9. Inspect for the following conditions that may affect the HO2S operation: HO2S for contamination, chafed, burnt, cut, pinched, or otherwise damaged HO2S wiring, exhaust system leaks or restrictions, EVAP canister purge, and for proper fuel pressure. Did you find and correct the condition? If yes, go to step  14. If no, go to next step.
  10. Inspect for poor connections at the HO2S 1 connector. Did you find and correct the condition? If yes, go to step  14. If no, go to step  12.
  11. Inspect for poor connections at the PCM harness connectors. Did you find and correct the condition? If yes, go to step  14. If no, go to step  13.
  12. Replace HO2S 1. After replacing sensor, go to step  14.
  13. Replace PCM. Perform PCM relearn procedure. See POWERTRAIN CONTROL MODULE  under PROGRAMMING. After replacing PCM, go to next step.
  14. Clear the DTCs with a scan tool. Turn ignition off for 30 seconds. Start engine. Operate the vehicle within the Conditions for Running the DTC. See CONDITIONS FOR RUNNING DTC . Does the DTC run and pass? If yes, go to next step. If no, go to step  2.
  15. Using scan tool, observe stored information and Capture Info. 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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