Circuit/System Verification

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

NOTE:

The engine oil level and the oil pressure are critical to the correct operation of the Cylinder Deactivation System. Verify that the engine has the correct oil level and the correct oil pressure before continuing with this diagnostic. Refer to Oil Pressure Diagnosis and Testing , . Inspect the Valve Lifter Oil Filter for a restriction or blockage. Refer to Valve Lifter Oil Filter Replacement .

Ignition ON, observe the scan tool DTC information.
Verify with a scan tool that DTC P0201-P0208, P0351-P0358, P3401, P3403, P3404, P3425, P3427, P3428, P3441, P3443, P3444, P3449, P3451, or P3452 is not set.
- If a DTC is set
  Refer to Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.
- If a DTC is not set
Engine idling at the normal operating temperature.
Verify there is no abnormal engine noise.
- If there is an abnormal engine noise
  Refer to Symptoms - Engine Mechanical for further diagnosis.
- If no abnormal engine noise
Verify the Cylinder Deactivation (Active Fuel Management) System Compression Test passes the compression test.
- If compression test failed
  Test the Q43 Valve Lifter Oil Manifold Assembly, refer to Cylinder Deactivation (Active Fuel Management) Valve Lifter Oil Manifold Diagnosis and Testing .
- If compression test passes
Operate the vehicle within the Conditions for Running the DTC. 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
  Refer to Circuit/System Testing.
- If the DTC is not set
All OK.