Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the appropriate B52 HO2S 2.
- Ignition ON, verify that the scan tool HO2S 2 parameter is between 400-520 mV.
- If greater than the specified range, test the signal circuit terminal B for a short to the heater control circuit terminal E. If the circuit/connections test normal, replace the K20 ECM.
- If all circuits/connections test normal, replace the appropriate B52 HO2S 2.