Cylinder Deactivation (Active Fuel Management) Oil Pressure Relief Valve Diagnosis and Testing

Cylinder Deactivation (Active Fuel Management) Oil Pressure Relief Valve Diagnosis and Testing


Tools Required
* EN-47971 Oil Pressure Gage Adapter
* J 21867 Pressure Gage
* J-21867-16 Oil Pressure Adapter







Important: This test is performed to verify the operation of the oil pressure relief valve. Refer to Cylinder Deactivation (Active Fuel Management) System Description (Cylinder Deactivation (Active Fuel Management) System Description) , Lubrication Description - Main Pressure Below 55 psi with Cylinder Deactivation (Active Fuel Management) Off (Description and Operation) , Lubrication Description - Main Pressure Above 55 psi with Cylinder Deactivation (Active Fuel Management) Off (Description and Operation) , Lubrication Description - Main Pressure Below 55 psi with Cylinder Deactivation (Active Fuel Management) On (Description and Operation) , and Lubrication Description - Main Pressure Above 55 psi with Cylinder Deactivation (Active Fuel Management) On (Description and Operation) .


1. Remove the oil filter and install the EN-47971 (1).
2. Install the J 21867 (2), or equivalent to the EN-47971 (1).




3. Remove the oil pressure sensor and install the J-21867-16 .




4. Install the J 21867 (1), or equivalent to the J-21867-16 .
5. Run the engine and measure the engine oil pressure while observing both gages.
Operate the throttle as required to increase and decrease the engine oil pressure.

* With the engine running and the lower pressure gage (2) measuring below 448 kPa (65 psi), both gages should display the same pressure reading. If the readings are not the same and the lower pressure gage (2) has a higher reading, the oil pressure relief valve is stuck in the open position or the valve lifter oil manifold filter is plugged.
* With the engine running and the lower pressure gage (2) measuring above 448 kPa (65 psi), the upper gage (1) should display no greater than 448 kPa (65 psi). If the reading on the upper pressure gage (1) is greater than 448 kPa (65 psi), the oil pressure relief valve is stuck in the closed position.

6. Repair, as required.