Diagnostic Procedures
WARNING: This page is about a different car, the 2002 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.
- 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.
- Install a scan tool. Start the engine and idle the engine at the normal operating temperature. Operate the engine above 1200 RPM for 2 minutes. Observe the HO2S voltage on the scan tool. Does the HO2S voltage vary outside 350-550 mV? If yes, go to next step. If no, go to step 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 cycle? If yes, go to next step. If no, see INTERMITTENT CONDITIONS under SELF-DIAGNOSTIC SYSTEM.
- Turn ON the ignition with the engine OFF. Disconnect the HO2S. Jumper the HO2S high signal circuit to a known-good ground. Jumper the HO2S low signal circuit to a known-good ground. Use the scan tool in order to monitor the HO2S voltage. Is the HO2S voltage below 200 mV? If yes, go to step 8. If no, go to next step.
- Remove both jumper wires. Use the DMM in order to measure the voltage from the HO2S low signal circuit to a battery ground. Is the voltage near 5 V? If yes, go to next step. If no, go to step 7.
- Turn OFF the ignition. Disconnect the PCM connector C1. Test for continuity of the HO2S high signal circuit. If no continuity is indicated on the DMM, repair the open circuit. Did you find and correct the condition? If yes, go to step 12. If no, go to step 10.
- Turn OFF the ignition. Disconnect the PCM connector C1. Test for continuity of the HO2S low signal circuit. If no continuity is indicated on the DMM, repair the open or the faulty connection. Did you find and correct the condition? If yes, go to step 12. If no, go to step 10.
- Test the 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.
- Replace the affected HO2S. After repairs, go to step 12.
- Inspect the 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.
- Replace the PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. Reprogram PCM. See POWERTRAIN CONTROL MODULE under PROGRAMMING. After repairs, go to next step.
- 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.
- 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.
NOTE:
Inspect the HO2S for being secure before proceeding with this DTC. A loose sensor could cause this DTC to set.