LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Buick >> 2003 >> Century Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls Self-Diagnostics - 3.1L Engine >> Diagnostic Tests >> DTC P0030: Ho2S 1 Heater Control Circuit >> Diagnostic Procedure
July 1: So it begins. Don't worry, this is not in the correct legal jurisdiction!

Diagnostic Procedure

  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. Start the engine. Allow the engine to idle at operating temperature. Observe the Heated Oxygen Sensor (HO2S) 1 heater current parameter using a scan tool. Is the amperage 0.25-0.85 amp? If yes, go to next step. If no, go to step  4.
  3. Observe the Freeze Frame/Failure Records for this DTC. Turn ignition switch to OFF position for 30 seconds. Start the engine. Operate the vehicle within the Conditions For Running Test. See CONDITIONS FOR RUNNING TEST . 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 next step. If no, go to INTERMITTENTS in TROUBLE SHOOTING - 3.1L CENTURY, GRAND PRIX & MALIBU article.
  4. Turn ignition switch to OFF position. Disconnect the HO2S 1 harness connector. Start the engine. Allow the engine to idle at operating temperature. Observe the DTC Info parameter using a scan tool for at least 30 seconds. Did the DTC fail this ignition? If yes, go to next step. If no, go to step  6.
  5. Test the HO2S 1 heater low control circuit for a short to voltage. Did you find and correct the condition? If yes, go to step  10. If no, go to step  7.
  6. 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  10. If no, go to step  8.
  7. 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  10. If no, go to step  8.
  8. Replace the HO2S 1. After repair, go to step  10.
  9. Replace PCM. See POWERTRAIN CONTROL MODULE in appropriate REMOVAL & INSTALLATION article. Perform PCM relearn procedure. See POWERTRAIN CONTROL MODULE  under PROGRAMMING. After replacing PCM, go to next step.
  10. Clear the DTCs using scan tool. Turn ignition switch to OFF position for 30 seconds. Start the engine. Operate the vehicle within the Conditions For Running Test. See CONDITIONS FOR RUNNING TEST . 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.
  11. Using the scan tool, observe the stored information in CAPTURE INFO. Are there any DTCs that have not been diagnosed? If yes, go to DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, system is okay at this time.
scientia non olet · About LEMON Manuals