LEMON Manuals: Even more car manuals for everyone
Home >> GMC >> 2003 >> Safari Van Cargo, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 123 (Engine Controls - Self-Diagnostics - 4.0L) >> Diagnostic Tests >> DTC P0133: Ho2S Bank 1 Sensor 1 - Slow Response >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different car, the 2002 Oldsmobile Aurora. 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, go to DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS  under SELF-DIAGNOSTIC SYSTEM.
    2. NOTE: If any DTCs are set except the HO2S DTCs, diagnose other DTCs first before proceeding with this procedure. See DIAGNOSTIC TROUBLE CODE DEFINITIONS .
  2. Ensure that the engine is at the operating temperature. Operate engine above 1200 RPM for 2 minutes. With a scan tool, observe the HO2S bank 1 sensor 1 voltage parameter. Does the scan tool indicate HO2S bank 1 sensor 1 voltage varying outside 400-500 mV? If yes, go to next step. If no, go to step  4.
  3. Review and record the scan tool Failure Records. Operate the vehicle within the Failure Records conditions. Using the scan tool, observe the Specific DTC Information for DTC P0133 until the test runs. Does the scan tool indicate that DTC P0133 failed this ignition? If yes, go to next step. If no, see DIAGNOSTIC AIDS .
  4. Inspect and test for the following conditions:
    • An exhaust leak.
    • Ensure that the HO2S bank 1 sensor 1 is installed correctly.
    • Damaged wiring.

    Did you find and correct the condition? If yes, go to step  13. If no, go to next step.

  5. Turn OFF the ignition. Disconnect the HO2S. Turn ON the ignition. Using the DMM, measure the voltage between the HO2S bank 1 sensor 1 high signal circuit on the PCM side and a good ground. Does the DMM indicate voltage near 450 mV? If yes, go to next step. If no, go to step  8.
  6. Jumper the high signal circuit to the low signal circuit on the PCM side. With a scan tool, observe HO2S bank 1 sensor 1 voltage parameter. Does the scan tool indicate that the HO2S bank 1 sensor 1 voltage is near 0 mV? If yes, go to step  9. If no, go to next step.
  7. Test the low signal circuit for an open or for high resistance. If the condition is found, repair as necessary. Did you find and correct the condition? If yes, go to step  13. If no, go to step  11.
  8. Test the high signal circuit for an open or for high resistance. If an open/high resistance condition is found, repair as necessary. Did you find and correct the condition? If yes, go to step  13. If no, go to step  11.
  9. Test for poor connections at the HO2S bank 1 sensor 1. If a poor connection conditions is found, repair as necessary. Did you find and correct the condition? If yes, go to step  13. If no, go to next step.
    10. 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. Remove the HO2S and visually inspect the portion of the sensor exposed to the exhaust stream in order to check for contamination. If contaminated, the portion of the sensor exposed to the exhaust stream will have a White powdery coating. Silicone contamination causes a high but false HO2S signal voltage (rich exhaust indication). The control module will then reduce the amount of fuel delivered to the engine, causing a severe driveability problem. Eliminate the source of contamination before replacing the oxygen sensor. Determine the cause of contamination before replacing the sensor.
  10. Inspect and test for the following:
    • Fuel contamination.
    • Engine oil or coolant consumption.
    • Use of improper RTV sealant.

    Replace the affected HO2S. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. After repairs, go to step  13.

  11. Test for poor connections at the PCM. Did you find and correct the condition? If yes, go to step  13. If no, go to next step.
  12. Replace the PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. Reprogram PCM. See POWERTRAIN CONTROL MODULE  under PROGRAMMING. After repairs, go to next step.
  13. Use the scan tool in order to clear the DTCs. 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.
  14. With a scan tool, observe the stored information, 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.
scientia non olet · About LEMON Manuals