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Home >> Chevrolet >> 2001 >> Venture Base, Van Passenger >> Repair and Diagnosis >> External Pages >> Different car >> Section 254 (Engine Controls Self-Diagnostics) >> Diagnostic Tests >> DTC P0140 & P0160: Ho2S Circuit - Insufficient Activity - Bank 1 & 2, Sensor 2 >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different car, the 2003 Chevrolet Corvette. 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: Inspect HO2S for being secure before proceeding with this DTC. A loose sensor could cause this DTC to set.
  2. Install a scan tool. Start the engine and idle the engine at the normal operating temperature. Change the throttle position more than 5 percent within 1 second, 6 times. Observe HO2S voltage with a scan tool. Is HO2S voltage outside 410-490 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 OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the 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 ON, with engine OFF. Disconnect HO2S. Jumper HO2S high signal circuit to a good ground. Jumper HO2S low signal circuit to a good ground. Observe HO2S voltage with a scan tool. Is HO2S voltage below 200 mV? If yes, go to step  8. If no, go to next step.
  5. Remove both jumper wires. Measure voltage between the HO2S low signal circuit and a good ground. Is voltage near 5 V? If yes, go to next step. If no, go to step  7.
  6. Turn ignition OFF. Disconnect PCM connector C1. Test for continuity of HO2S high signal circuit. If no continuity is indicated, repair the open or faulty connection. Did you find and correct the condition? If yes, go to step  12. If no, go to step  10.
  7. Turn ignition OFF. Disconnect PCM connector C1. Test for continuity of HO2S low signal circuit. If no continuity is indicated, repair the open or faulty connection. Did you find and correct the condition? If yes, go to step  12. If no, go to step  10.
  8. Inspect HO2S circuits for a faulty connection at the HO2S harness connector. If you find a faulty connection, replace or repair the terminal as necessary. Did you find and correct the condition? If yes, go to step  12. If no, go to next step.
  9. Replace affected HO2S. See HEATED OXYGEN SENSOR under SENSORS in REMOVAL & INSTALLATION - CORVETTE article. Did you complete the replacement? Did you complete the replacement? If yes, go to step  12.
  10. Inspect HO2S circuits for a faulty connection at the PCM. If you find a faulty connection, replace or repair the terminal as necessary. Did you find and correct the condition? If yes, go to step  12. If no, go to next step.
  11. Replace PCM. See POWERTRAIN CONTROL MODULE under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION - CORVETTE article. Did you complete the replacement? If yes, go to next step.
  12. 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 the 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 step  2. If no, go to next step.
  13. 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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