Important: If it is found that one or more of the active fuel management (AFM) lifters are not operating properly and needs replacing, replace all 6 AFM lifters and the lifter guide as an assembly.

Tools Required

Important: 

The Cylinder Deactivation (AFM) Valve Lifter Oil Manifold Diagnosis and Testing procedure consists of two basic tests.

The Fuel Injector Wiring Harness Power and Resistance Test will test for the following conditions:

The LOMA air bench test provides a maximum 206 kPa (30 psi) of filtered shop air to the manifold and will test each solenoid/valve for the following conditions:

In this test you will individually depress buttons 1 through 3 on the EN-46999 in order to activate each of the solenoid/valves. When activating each solenoid/valve, a clicking noise should be heard from each of the solenoid valves in the LOMA. If a clicking noise is not heard when activating each solenoid/valve, use the J 39200 to measure and record a resistance reading which will be used in the diagnosis.

Important: In order to accurately diagnose the AFM system, it is necessary to use the J 39570 to detect the audible clicks when cycling the valves in the LOMA. Failure to do so may result in the misdiagnosis of a properly functioning system.

1. Connect the 12 volt power supply connectors (7) of the EN-46999 to a 12 volt power supply.
2. Verify the power light (8) on the tool is illuminated.

•	If the light on the tool intermittently goes out when connected to a 12 volt power supply, verify that your connections are good.

•	If the light on the tool is not illuminated when connected to a 12 volt power supply, test and/or replace the 3 amp fuse.




3. Disconnect the 16-way fuel injector harness from the engine harness, and connect the power lead on the EN-46999-10 cable to the fuel injector harness connector.
4. Depress button number 1 on the tool to activate solenoid/valve for cylinder number 1. You should hear a clicking sound from the solenoid/valve, indicating that the solenoid/valve is working properly.
5. Depress button number 2 on the tool to activate solenoid/valve for cylinder number 3. You should hear a clicking sound from the solenoid/valve, indicating that the solenoid/valve is working properly.
6. Depress button number 3 on the tool to activate solenoid/valve for cylinder number 5. You should hear a clicking sound from the solenoid/valve, indicating that the solenoid/valve is working properly.
7. If after testing, it has been determined that one or more of the solenoid/valves is not functioning properly, continue to step number 9.
8. If after testing, it has been determined that the solenoid/valves are functioning properly, reevaluate the vehicle for active fuel management (AFM) functional or DTC concerns before proceeding. Refer to Cylinder Deactivation (Active Fuel Management) System Diagnosis for the 3.9L engine.



9. Connect the resistance lead on the EN-46999-10 cable to the 16-way fuel injector harness connector.
10. Connect the leads on the J 39200 to the EN-46999 .
11. With the J 39200 connected, depress buttons 1, 2, and 3 on the EN-46999 . Record the resistance reading for each solenoid/valve.
12. Remove the upper intake manifold to gain access to the LOMA connector. Refer to Upper Intake Manifold Replacement .

Important: The power lead on the EN-46999-10 is a one way connector. Ensure proper alignment prior to installing the connector into the LOMA to avoid damaging the connector or the LOMA.

13. Connect the power lead on the EN-46999-10 to the LOMA connector.



14. Depress button number 1 on the tool to activate solenoid/valve for cylinder number 1 (3). You should hear a loud clicking sound from the solenoid/valve, indicating that the solenoid/valve is working properly.
15. Depress button number 2 on the tool to activate solenoid/valve for cylinder number 3 (2). You should hear a loud clicking sound from the solenoid/valve, indicating that the solenoid/valve is working properly.
16. Depress button number 3 on the tool to activate solenoid/valve for cylinder number 5 (1). You should hear a clicking sound from the solenoid/valve, indicating that the solenoid/valve is working properly.
17. If all solenoids/valves are found to be operating properly, proceed to step number 19.
18. If one of more of the solenoid/valves are not working properly, replace the LOMA. Refer to Valve Lifter Oil Manifold Replacement .




Important: The resistance lead on the EN-46999-10 is a one way connector. Ensure proper alignment prior to installing the connector into the LOMA to avoid damaging the connector or the LOMA.

19. Connect the resistance lead on the EN-46999-10 cable to the LOMA connector, making sure to establish a solid connection.
20. With the J 39200 still connected, depress buttons 1, 2, and 3 on the EN-46999 . Record the resistance reading for each solenoid/valve.
21. Compare the two resistance values taken in steps number 11 and 20 with the resistance values contained in the AFM LOMA specifications chart. Refer to Engine Electrical Specifications.

•	If the resistance values recorded for the LOMA are greater or less than the allowable limits, replace the LOMA. Refer to Valve Lifter Oil Manifold Replacement .

•	If the resistance values recorded for the LOMA while connected inline with the fuel injection wiring harness are greater or less than the allowable limits, replace fuel injection wiring harness. Refer to Fuel Injector Wiring Harness Replacement.

•	If all the resistance values recorded are within specifications, proceed to the LOMA Air Bench Test.

In this test you will individually depress buttons 1 through 3 on the EN-46999 in order to activate each of the solenoid/valves. When activating each solenoid/valve, a loud click should be heard from the solenoid and an increased amount of air will exit the outlet ports.

1. Remove the LOMA from the vehicle. Refer to Valve Lifter Oil Manifold Replacement .
2. Install the EN-46999-6  (1) to the manifold, ensuring that the original oil manifold gasket and filter are in place, and that the air passage holes on the EN-46999-6 are lined up properly with the air passages in the gasket as well as the LOMA. Failure to do so will result in incorrect test results.

Notice: Refer to Fastener Notice in the Preface section.

3. Install two of the manifold bolts (2) to the EN-46999-6 .

Tighten
Tighten the bolts to 25 N·m (18 lb ft).




4. Connect the air out hose (2) of the EN-46999  (5) to the EN-46999-6  (1). Verify the air supply switch (4) is in the OFF position.
5. Connect the air in hose (6) of the EN-46999 to a shop air source.
6. Ensure that the 12 volt power supply connectors (7) of the EN-46999 are properly connected to a 12 volt power supply.
7. Verify the power light (8) on the tool is illuminated.

•	If the light on the tool intermittently goes out when connected to a 12 volt power supply, verify that your connections are good.

•	If the light on the tool is not illuminated when connected to a 12 volt power supply, test and/or replace the 3 amp fuse.

Important: The power lead on the EN-46999-10 is a one way connector. Ensure proper alignment prior to installing the connector into the LOMA to avoid damaging the connector or the LOMA.

8. Connect the power lead of the EN-46999-10 cable (3) to the LOMA, making sure to establish a good connection.

Important: Some air leakage around EN-46999-6  (1) during testing is normal.

9. Turn the air supply switch (4) on the EN-46999 to ON.



10. Depress button number 1 on the tool to activate solenoid/valve number 1. The solenoid/valve for cylinder number 1 should open, allowing air to exit the outlet ports (1) of the manifold.
11. Depress button number 2 on the tool to activate solenoid/valve 2. The solenoid/valve for cylinder number 3 should open, allowing air to exit the outlet ports (2) of the manifold.
12. Depress button number 3 on the tool to activate solenoid/valve 3. The solenoid/valve for cylinder number 5 should open, allowing air to exit the outlet ports (3) of the manifold.
13. When the test is completed, turn the air source switch on the EN-46999 to the OFF position and disconnect the tool from the 12 volt power supply, shop air source, and the LOMA.
14. Remove the EN-46999 from the LOMA.
15. If after testing, it has been determined that one or more of the solenoid/valves is not functioning properly, replace the LOMA as an assembly. Refer to Valve Lifter Oil Manifold Replacement .
16. If after testing, it has been determined that the solenoid/valves are functioning properly, replace all the valve lifters as an assembly. Refer to Valve Lifter Replacement .