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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 405 (Engine Controls - Self-Diagnostics) >> Diagnostic Tests >> DTC P0130 & P0150: Ho2S Bank 1 & 2, Sensor 1 Circuit >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different car, the 2003 Cadillac Seville and 2003 Cadillac DeVille. 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. Start the engine. Allow the engine to idle at operating temperature. Clear the DTC and record the Freeze/Frame Failure Records. Observe the affected Heated Oxygen Sensor (HO2S) 1 voltage parameter with a scan tool. Does the affected HO2S 1 voltage fluctuate rapidly above and below 350-500 mV? If yes, go to next step. If no, go to step  4.
  3. Observe the Freeze Frame/Failure Records for this DTC. Turn off the ignition for 30 seconds. Start the engine. Operate the vehicle within the 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 cycle? If yes, go to next step. If no, see INTERMITTENT CONDITIONS  under SELF-DIAGNOSTIC SYSTEM.
  4. Turn ignition off. Disconnect the affected HO2S 1 connector. Turn ignition on, with engine off. Measure the voltage between the affected HO2S 1 high signal circuit, on the engine harness side connector, and a good ground. Is the affected HO2S 1 voltage 400-500 mV? 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 affected HO2S 1 high signal circuit of the engine harness and the affected HO2S 1 low reference circuit of the engine harness. Turn ignition on, with engine off. Observe the affected HO2S 1 voltage with a scan tool. Is the affected HO2S 1 voltage less than 25 mV? If yes, go to step  8. If no, go to step  7.
  6. Test the affected HO2S 1 high signal circuit for an open or high resistance. Did you find and correct the condition? If yes, go to step  13. If no, go to step  10.
  7. Test the affected HO2S 1 low signal circuit for an open or high resistance. Did you find and correct the condition? If yes, go to step  13. If no, go to step  10.
    8. CAUTION: See SERVICE PRECAUTIONS  to prevent damage to oxygen sensors when servicing or testing.
  8. Inspect for the following that may affect the HO2S operation:
    • HO2S for contamination.
    • Chafed, burnt, cut, pinched, or otherwise damaged HO2S wiring.
    • The HO2S must have a clean air reference in order to function properly. This clean air reference is obtained by way of the HO2S wires. Obstruction of the air reference and degraded HO2S performance could result from any attempt to repair the above conditions.
    • Exhaust system leaks or restrictions.
    • Evaporative Emissions (EVAP) system malfunction. See INSPECTION/MAINTENANCE EVAPORATIVE EMISSION SYSTEM SET PROCEDURE  under DRIVE CYCLES.
    • The fuel pressure. See appropriate BASIC FUEL SYSTEM CHECKS in BASIC DIAGNOSTIC PROCEDURES article.

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

  9. Test for an intermittent and/or poor connections at the affected HO2S 1. Did you find and correct the condition? If yes. go to step  13. If no, go to step  11.
  10. Test for an intermittent and/or poor connections at the PCM. Did you find and correct the condition? If yes, go to step  13. If no, go to step  12.
  11. Replace affected HO2S. See HEATED OXYGEN SENSOR under SENSORS in REMOVAL & INSTALLATION - DEVILLE & SEVILLE article. Did you complete the replacement? If yes, go to step  13.
  12. Replace PCM. See POWERTRAIN CONTROL MODULE under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION - DEVILLE & SEVILLE article. Did you complete the replacement? If yes, go to next step.
  13. Clear the DTCs with a scan tool. Turn off the ignition for 30 seconds. Start the engine and operate vehicle within the Conditions For Running DTC. You may also operate vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition cycle? If yes, go to step  2. If no, go to next step.
  14. Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? If yes, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, system is okay.
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