LEMON Manuals: Even more car manuals for everyone
Home >> GMC >> 2003 >> Safari Van Cargo, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 81 (Engine Controls - Self-Diagnostics - 4.8L, 5.3L & 6.0L) >> Diagnostic Tests >> DTC P1134 & P1154: Ho2S Transition Time Ratio - Bank 1 & 2, Sensor 1 (6.0L W/Isolated Ground) >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page does not describe the selected car, but rather 11 other vehicles, including the 2002 GMC Yukon XL, 2002 GMC Yukon, 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, and 2002 Chevrolet Tahoe. However, it is still accessible from the selected car via links, so may be relevant.
  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. NOTE: Allow the engine to cool for one-half hour before proceeding with this diagnostic. This allows the HO2S signal voltage to return to bias voltage, approximately 447 mV.
  2. Install a scan tool. Turn ON the ignition, with the engine OFF. Command the HO2S heater ON with a scan tool. Immediately observe the affected HO2S voltage for 2 minutes. Does the HO2S voltage go from bias voltage to more than or less than 300-600 mV? If yes, go to next step. If no, go to step  5.
  3. Start the engine. Allow the engine to reach operating temperature. Raise and hold the engine speed at 1200 RPM for 2 minutes. Observe the HO2S voltage with a scan tool. Is the HO2S voltage varying outside 350-550 mV? If yes, go to next step. If no, go to step  5.
  4. Observe the Freeze Frame/Failure Records data for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running DTC, or as close to the Freeze Frame/Failure Records data that you observed. Does the DTC fail this ignition? If yes, go to next step. If no, see DIAGNOSTIC AIDS .
  5. Are Both DTCs P1134 and P1154 set? If yes, go to next step. If no, go to step  7.
  6. Turn OFF the ignition. Disconnect the HO2S bank 1 sensor 1 connector. Probe the HO2S low reference circuit with a test lamp that is connected to battery positive. Does the test lamp illuminate? If yes, go to step  11. If no, go to step  10.
  7. Turn OFF the ignition. Disconnect the affected HO2S connector. Jumper the HO2S high signal circuit to the low reference circuit. Turn the ignition ON, with the engine OFF. Observe the HO2S voltage with a scan tool. Is the HO2S voltage less than 200 mV? If yes, go to step  11. If no, go to next step.
  8. Turn OFF the ignition. Disconnect the PCM connector containing the HO2S high signal circuit. Test the HO2S high signal circuit for an open. Did you find and correct the condition? If yes, go to step  22. If no, go to next step.
  9. Test for an open between terminal "A" of the affected sensor harness connector and one of the following PCM terminals:
    • If DTC P1134 is set use C1-29.
    • If DTC P1154 is set use C1-26.

    Did you find and correct the condition? If yes, go to step  22. If no, go to step  18.

  10. Disconnect the PCM connector containing the HO2S low reference circuit. Test the low reference circuit for an open between HO2S bank 1 sensor 1 terminal "A" and PCM terminal C1-63. Did you find and correct the condition? If yes, go to step  22. If no, go to step  18.
  11. If applicable, remove the jumper from the previous step. Disconnect the opposite bank HO2S connector. Perform the following:
    • If only one DTC is set, P1134 or P1154, probe the affected HO2S heater high control circuit with a test lamp that is connected to a good ground.
    • If both DTC P1134 and P1154 are set, probe HO2S bank 1 sensor 1 heater high control circuit with a test lamp that is connected to a good ground.

    Command the HO2S heater ON with a scan tool. Does the test lamp illuminate? If yes, go to next step. If no, go to step  13.

  12. Connect a test lamp between the affected HO2S heater high control circuit and the HO2S heater low reference circuit. Command the HO2S heater ON with a scan tool. Does the test lamp illuminate? If yes, go to step  14. If no, go to step  16.
  13. Disconnect the PCM connector containing the HO2S heater high control circuit. Test the HO2S heater high control circuit for an open or short to ground. Did you find and correct the condition? If yes, go to step  22. If no, go to step  18.
    14. NOTE: Perform the following test on HO2S bank 1 sensor 1 and HO2S bank 2 sensor 1. A condition in either sensor will cause this DTC to set.
  14. Test the HO2S heater high control circuit, sensor side, for a short to the HO2S body. Did you find the condition? If yes, go to step  21. If no, go to next step.
    15. NOTE: Perform the following test on HO2S bank 1 sensor 1 and HO2S bank 2 sensor 1. A condition in either sensor will cause this DTC to set.
  15. Measure the resistance between the HO2S heater high control circuit, sensor side, and the HO2S heater low reference circuit, sensor side. Does the resistance of either sensor measure above or below 2-50 ohms? If yes, go to step  21. If no, go to step  17.
  16. Disconnect the PCM connector containing the HO2S heater low reference circuit. Test the HO2S heater low reference circuit for an open. Did you find and correct the condition? If yes, go to step  22. If no, go to step  18.
    17. NOTE: Before replacing the suspected HO2S, inspect for and remove any source of contamination.
  17. Inspect for the following conditions:
    • The use of incorrect silicone RTV sealant.
    • An engine coolant leak into the combustion chamber.
    • Excessive engine oil consumption.
    • Fuel contamination.
    • An exhaust system leak or restriction.
    • Incorrect fuel pressure.

    Did you find and correct the condition? If yes, go to step  20. If no, go to step  19.

  18. Inspect for poor connections at the harness connector of the PCM. Did you find and correct the condition? If yes, go to step  22. If no, go to step  20.
  19. Inspect for poor connections at the harness connector of the affected HO2S. Did you find and correct the condition? If yes, go to step  22. If no, go to step  21.
  20. Replace the PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. Reprogram PCM. See POWERTRAIN CONTROL MODULE  under PROGRAMMING. After repairs, go to step  22.
  21. Replace the affected HO2S. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. After repairs, go to next step.
  22. Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running DTC. Does the DTC run and pass? If yes, go to next step. If no, go to step  2.
  23. 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.
scientia non olet · About LEMON Manuals