2.0L & 2.8L
NOTE:
Also, perform testing under any Heated Oxygen Sensor (HO2S) related DTCs in appropriate SELF-DIAGNOSTICS article.
- Ensure base settings for ignition and idle are okay. Ensure exhaust system is not leaking between catalytic converter and cylinder head. Ensure voltage supply for oxygen sensor heater is okay.
- Connect scan tool to Data Link Connector (DLC) located below A/C-heater control panel. See TESTS W/CODES - GASOLINE article. With scan tool in READ MEASURING VALUE BLOCK function, ensure coolant temperature is greater than 176°F (80°C), as displayed in field No. 2 of scan tool.
- Allow engine to run for 2 minutes at idle, then read oxygen sensor factor (signal) in field No. 3 of scan tool. Display value must fluctuate. If value in display field No. 3 does not fluctuate, briefly accelerate engine and repeat test.
- If oxygen sensor value does not change even during acceleration, disconnect engine coolant temperature sensor. Erase DTC memory. Disconnect oxygen sensor wiring harness connector.
- Ground oxygen sensor wiring harness connector terminal No. 4. See Fig 1 . Value in display field No. 3 must increase. If value increases, replace oxygen sensor. If value does not change, repair circuit or replace ECM as necessary. After repairs, erase DTC memory and select END OUTPUT function.