Signal Circuit Inspection
- Ignition "OFF".
- Disconnect Battery (-) terminal.
- Refer to ENGINE COOLANT TEMPERATURE SENSOR (ECTS) and ENGINE CONTROL MODULE (ECM) and disconnect Engine Coolant Temperature Sensor and ECM/PCM connector.
- Measure resistance between Pin No. 1 (Signal) terminal of Downstream O2 Sensor harness connector and Pin No. 58 (Signal) terminal of ECM/PCM harness connector.
Specification: Approx. below 1Ω
- Is the measured value within specification?
YES
- go to "Component Inspection " procedure.
NO
- Repair open or short in signal circuit between Downstream O2 Sensor and ECM/PCM and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.