Circuit/System Verification

WARNING: This page is about a different variant/trim than selected.

Ignition ON.
Verify no HO2S heater DTCs are set.
- If a DTC is set
  Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
- If a DTC is not set
Verify none of the following conditions exist:
- Lean or rich fuel injectors-Refer to Fuel Injector Diagnosis Fuel Injector Diagnosis (LSA)
- Water intrusion in the B52 HO2S harness connector
- Low or high fuel system pressure-Refer to Fuel System Diagnosis Fuel System Diagnosis (LSA)
- Fuel that is contaminated-Refer to Alcohol/Contaminants-in-Fuel Diagnosis
- Fuel saturation of the evaporative emission (EVAP) canister
- Exhaust leaks
- Engine vacuum leaks
- Engine oil consumption-Refer to Oil Consumption Diagnosis
- Engine coolant consumption-Refer to Loss of Coolant (LFX, L99/LS3, LS7)Loss of Coolant (LSA)
- If any of the conditions exist
  Repair as necessary.
- If none of the conditions exist
Operate the vehicle within the Conditions for Running the. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Verify the DTC does not set.
- If the DTC sets
  Test or replace the appropriate B52 Heated Oxygen Sensor.
- If the DTC does not set
All OK.