System Operation Description:
The intake valve actuator allows the engine to vary the amount of time that the intake valves are open. The intake valve actuator is a hydraulic system that uses the engine oil to operate. Oil is allowed to flow in and out of the intake valve actuator when the intake valve actuator is not activated. The solenoid is activated to trap the oil and and allow the actuator to hold the rocker arm down.
Test Step 1. Inspect Electrical Connectors and Wiring
A. Inspect the J2/P2 ECM connector, the front valve cover connector, the rear valve cover connector, and the wiring associated with the intake valve actuator solenoids.
B. Perform a pull test on all of the wires that are associated with the suspect solenoid.
Expected Result:
All the connectors and wiring are OK.
Results:
• OK – Proceed to Test Step 2.
• Not OK
Repair: Repair the connectors and/or the wiring.
STOP.
Test Step 2. Perform the “Intake Valve Actuator Solenoid Test”
A. Connect the Caterpillar Electronic Technician (Cat ET) to the data link connector.
B. Turn the key switch to the ON position.
Note: Do not start the engine.
C. Access the “Intake Valve Actuator Solenoid Test” in the “Special Tests” under the “Service” menu.
D. Activate the test.
Expected Result:
The “Intake Valve Actuator Solenoid Test” indicates an “Open” or a “Short” for one or more of the intake valve actuator solenoids.
Note: If two solenoid that share a common wire have faults, the source of the problem is most likely due to the common wire.
Results:
• “Open” – One or more of the solenoids is open during the “Intake Valve Actuator Solenoid Test”.
Proceed to Test Step 3.
• “Short” – One or more of the solenoids is shorted during the “Intake Valve Actuator Solenoid Test”.
Proceed to Test Step 6.
Test Step 3. Create a Short Circuit at the Valve Cover
A. Turn the key switch to the OFF position.
B. Disconnect the valve cover connector for the suspect solenoid.
C. Inspect the terminals on the valve cover and the valve cover connector for damage.
Note: Refer to the Figure 119 and Figure 120.
D. Fabricate a jumper wire in order to short the two wires for the suspect solenoid on the harness.
E. Turn the key switch to the ON position.
F. Start the “Intake Valve Actuator Solenoid Test” on Cat ET.
Note: Disconnecting the valve cover connector will cause the other solenoids to be “Open” during the “Intake Valve Actuator Solenoid Test”.
Expected Result:
The “Open” changes to a “Short” when the jumper wire is installed.
Results:
• OK – The “Open” changes to a “Short”.
Reconnect the valve cover connector. Proceed to Test Step 5.
• Not OK – There is still an “Open”. Leave the valve cover connector disconnected. Proceed to Test Step 4.
Test Step 4. Create a Short Circuit at the ECM
A. Turn the key switch to the OFF position.
B. Disconnect the J2/P2 ECM connector.
C. Inspect the terminals on the J2 and P2 ECM connectors for damage.
Note: Refer to the Figure 121 for pin locations.
D. Remove the return wire and the common wire for the suspect solenoid from the P2 ECM connector.
E. Fabricate a jumper wire in order to short the two pins for the suspect solenoid at the ECM. Crimp a socket to each end of the jumper wire. Insert the jumper wire into the P2 ECM connector.
F. Reconnect the J2/P2 ECM connector.
G. Turn the key switch to the ON position.
H. Start the “Intake Valve Actuator Solenoid Test” on Cat ET.
Expected Result:
The “Open” changes to a “Short” when the jumper wire is installed.
Note: Disconnecting the common wire for the suspect solenoid will cause an “Open” in the solenoid that shares the common wire with the suspect solenoid.
Results:
• OK – The “Open” changes to a “Short”. There is a problem in the harness between the ECM and the valve cover.
Repair: Repair the harness.
Verify that the repair eliminates the problem.
STOP.
• Not OK – There is still an “Open”.
Repair: Temporarily connect a test ECM.
If the test ECM repairs the problem, reconnect the suspect ECM.
If the problem returns, replace the ECM.
Verify that the repair eliminates the problem.
STOP.
Test Step 5. Create a Short Circuit at the Solenoid
A. Turn the key switch to the OFF position.
B. Remove the valve cover.
C. Disconnect the connector on the suspect solenoid.
D. Inspect the terminals on the solenoid connector for damage.
E. Fabricate a jumper wire in order to short the two wires for the suspect solenoid on the solenoid connector. Crimp a pin to each end of the jumper wire.
F. Make sure that the solenoid connector securely holds the jumper wire.
Note: Worn and/or damaged terminals on the solenoid connector could cause an intermittent “Open”.
G. Turn the key switch to the ON position.
H. Start the “Intake Valve Actuator Solenoid Test” on Cat ET.
Expected Result:
The “Open” changes to a “Short” when the jumper wire is installed.
Results:
• OK – The “Open” changes to a “Short”. There is a problem with the solenoid.
Repair: Temporarily connect a new intake valve actuator unit.
If the new intake valve actuator unit repairs the problem, reconnect the suspect intake valve
actuator unit.
If the problem returns, replace the intake valve
actuator unit.
Verify that the repair eliminates the problem.
STOP.
• Not OK – There is still an “Open”. There is a problem in the harness between the solenoid and the valve cover.
Repair: Repair the harness.
Verify that the repair eliminates the problem.
STOP.
Test Step 6. Create an Open Circuit at the Valve Cover
A. Disconnect the valve cover connector for the suspect solenoid.
B. Check the valve cover connector for moisture.
C. Turn the key switch to the ON position.
D. Start the “Intake Valve Actuator Solenoid Test” on Cat ET.
Note: Disconnecting the valve cover connector will cause some of the other solenoids to be open during the “Intake Valve Actuator Solenoid Test”.
Expected Result:
The “Short” changes to a “Open” when the valve cover connector is disconnected.
Results:
• OK – The “Short” changes to a “Open” when the valve cover connector is disconnected. Proceed to Test Step 8.
• Not OK – There is still a “Short” when the connectors on the valve cover are disconnected.
Proceed to Test Step 7.
Test Step 7. Create an Open Circuit at the ECM
A. Turn the key switch to the OFF position.
B. Disconnect the J2/P2 ECM connector.
C. Check the J2/P2 ECM connector for moisture.
D. Remove the return wire for the suspect solenoid from the P2 ECM connector.
E. Reconnect the J2/P2 ECM connector.
F. Turn the key switch to the ON position.
G. Start the “Intake Valve Actuator Solenoid Test” on Cat ET.
Expected Result:
The “Short” changes to an “Open” when the return wire is removed from the P2 ECM connector.
Results:
• OK – The “Short” changes to an “Open” when the return wire is removed from the P2 ECM connector. There is a problem in the harness between the ECM and the valve cover.
Repair: Repair the harness.
Verify that the repair eliminates the problem.
STOP.
• Not OK – There is still a “Short”.
Repair: Temporarily connect a test ECM.
If the test ECM repairs the problem, reconnect the suspect ECM.
If the problem returns, replace the ECM.
Verify that the repair eliminates the problem.
STOP.
Test Step 8. Create an Open Circuit at the Solenoid
A. Turn the key switch to the OFF position.
B. Remove the valve cover.
C. Disconnect the connector on the suspect solenoid.
D. Inspect the solenoid connector for damage.
E. Turn the key switch to the ON position.
F. Start the “Intake Valve Actuator Solenoid Test” on Cat ET.
Expected Result:
The “Short” changes to a “Open” when the solenoid connector is disconnected.
Results:
• OK – The “Short” changes to an “Open” when the solenoid connector is disconnected. There is a problem with the intake valve actuator solenoid.
Repair: Temporarily connect a new intake valve actuator unit.
If the new intake valve actuator unit repairs the problem, reconnect the suspect intake valve actuator unit.
If the problem returns, replace the intake valve actuator unit.
Verify that the repair eliminates the problem.
STOP.
• Not OK – There is still a “Short”. There is a problem with the harness between the solenoid and the valve cover.
Repair: Repair the harness.
Verify that the repair eliminates the problem.
STOP.