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Home >> Pontiac >> 2003 >> Aztek AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls Self-Diagnostics >> Diagnostic Tests >> DTC P0130: Ho2S Circuit - Sensor 1 >> Diagnostic Procedures
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Diagnostic Procedures

  1. Did you perform the Diagnostic System Check - Engine Controls? If yes, go to next step. If no, see DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS  under SELF-DIAGNOSTIC SYSTEM.
  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 above and below 350-550 mV? 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 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 cycle? If yes, go to next step. If no, see INTERMITTENTS in TROUBLE SHOOTING - NO CODES - 3.4L AZTEK & RENDEZVOUS article.
  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 DVOM. Is HO2S voltage 0.425-0.500 V? 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 high signal circuit, and HO2S 1 low signal circuit. Turn ignition on, with engine off. Observe the HO2S 1 voltage on the scan tool. Does the scan tool display less than 25 mV? If yes, go to step  8. If no, go to next step.
  6. Turn ignition off. Disconnect both PCM connectors. Measure the resistance of each of the following circuits with a DVOM:
    • HO2S 1 high signal circuit between HO2S connector and the PCM connector.
    • HO2S 1 low signal circuit between HO2S connector and the PCM connector.
    • HO2S 1 low reference circuit between pin C1-29 and pin C2- 80 of the PCM connectors.

    Is the resistance of each circuit less than 5 ohms? If yes, go to step  10. If no, go to step  11.

  7. Remove the jumper wire from the previous step. 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 step  4 of DTC P0135: HO2S HEATER CIRCUIT - SENSOR 1 .
  8. Inspect for the following that may affect the HO2S operation: HO2S for contamination. Chafed, burnt, cut, pinched, or otherwise damaged HO2S wiring. Exhaust system leaks or restrictions. EVAP system malfunction. Incorrect fuel pressure. Did you find and correct the condition? If yes, go to step  14. If no, go to next step.
  9. Test for an intermittent and for a poor connection at the harness connector of the HO2S 1. Did you find and correct the condition? If yes, go to step  14. If no, go to step  12.
  10. Test for an intermittent and for a poor connection at the harness connector of the PCM. Did you find and correct the condition? If yes, go to step  14. If no, go to step  13.
  11. Repair open or high resistance on the affected circuit. After repairs, go to step  14.
  12. Replace HO2S 1 sensor. See REMOVAL & INSTALLATION - AZTEC & RENDEZVOUS article. After repairs, go to step  14.
  13. Replace PCM. See REMOVAL & INSTALLATION - AZTEC & RENDEZVOUS article. Reprogram PCM. See POWERTRAIN CONTROL MODULE  under PROGRAMMING. After repairs, 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 . You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition? If yes, go to step  2. If no, go to next step.
  15. Observe the stored information, Capture Info with a scan tool. 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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