Test TC-102A - Left/Upstream O2 Sensor Slow Response
NOTE:
For connector terminal identification, refer to CONNECTOR IDENTIFICATION . For wiring diagram, see WIRING DIAGRAMS
article in this section.
- 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 Oxygen Sensors (O2S), and perform TEST VER-5A. If engine mechanical condition is okay, go to next step.
- Turn ignition off. Disconnect left/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 left/upstream O2S (component side), ground circuit (Gray wire). See Fig 1. 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 Powertrain Control Module (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 left/upstream O2S and perform TEST VER-5A.