Test TC-122A - Right/Upstream O2 Sensor Slow Response
NOTE:
For connector terminal identification, refer to CONNECTOR IDENTIFICATION . For wiring diagram, see WIRING DIAGRAMS
article in this section.
- RIGHT/UPSTREAM O2S SHORTED TO VOLTAGE DTC sets if right/upstream Oxygen Sensor (O2S) voltage is more than 1.5 volts with engine running and engine at operating temperature. Possible causes are: O2S output circuit shorted to power circuit, defective O2S, defective PCM, open circuit, or defective wiring or connectors. Go to next step.
- Start engine. Check exhaust system for leaks between engine and catalytic converter. Repair exhaust system as necessary and perform TEST VER-5A. If exhaust system is okay, go to next step.
- Check exhaust for excessive smoke caused by oil consumption. Repair engine mechanical condition as necessary, replace catalytic converter and O2Ss, and perform TEST VER-5A. If engine mechanical condition is okay, go to next step.
- Turn ignition off. Disconnect right/upstream O2S connector. Inspect connector and terminals for damage. Repair connector and terminals as necessary and perform TEST VER-5A . If connector and terminals are okay, go to next step.
- Using scan tool in ohmmeter mode, check resistance of right/upstream O2S (component side), ground circuit (Gray wire). See Figure. If resistance is 5 ohms or more, repair open ground circuit and perform TEST VER-5A. If resistance is less than 5 ohms, go to next step.
- Disconnect PCM connectors. Inspect connectors and terminals for damage. Repair connectors and terminals as necessary and perform TEST VER-5A . If connectors and terminals are okay, replace right/upstream O2S and perform TEST VER-5A.
NOTE:
A break in test sequence occurs at this point. Sequence skips from TEST TC-122A to TEST TC-124A. No tests have been omitted.