Circuit/System Verification

Vehicle OFF, allow the engine to cool to be within the temperatures listed in the Conditions for Running the DTC.
Engine running.
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. 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
1. Verify that none of the conditions listed below exists with the air intake system:
  - Damage, restriction or modification
  - Dirty or deteriorating air filter element
  - Crankcase ventilation system for correct operation
  - Water intrusion
  - Vacuum leak and other unmetered air downstream of the mass air flow (MAF) sensor
  - Intake manifold leak
  - If any of the conditions exist
    Repair as necessary.
  - If none of the conditions exist
2. Verify that none of the conditions listed below exists with the exhaust system:
  - Exhaust leak
  - Damaged, restricted or modified exhaust system - Refer to Symptoms - Engine Exhaust .
  - If any of the above conditions exist
    Repair as necessary.
  - If none of the conditions exist
3. If all of the above conditions test normal, inspect for an engine mechanical condition that could alter the air flow into the combustion chamber. Refer to Symptoms - Engine Mechanical .
- If the DTC does not set
All OK.