Operation CHARM: Car repair manuals for everyone.

P3426






P3426-CYLINDER 4 DEACTIVATION CONTROL PERFORMANCE





For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

When all criteria has been met, power is supplied to each MDS Solenoid when the engine is making a transition from 8 cylinder mode to 4 cylinder mode. By actuating the solenoid, oil pressure is raised to the pair of lifters that coincide with each particular solenoid. The oil pressure pushes in the locking pins that allows the lifter to collapse, decoupling the valves and camshaft.

- When Monitored:
Transition from 8 to 4 cylinder mode.

- Set Condition:
The MDS fails to engage for cylinder 4.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. ACTIVE DIAGNOSTIC TROUBLE CODE (DTC)

NOTE: Diagnose any Misfire DTCs before continuing.

1. Turn the ignition on.
2. With a scan tool, read DTCs.

Is the DTC active at this time?

Yes

- Go To 2

No

- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test

2. CHECKING MDS SOLENOID CIRCUIT FROM THE PCM SIDE OF THE C101 INLINE CONNECTOR

NOTE: The DTC must not be active for the actuator test to operate properly, clear all DTC before continuing.





1. Turn the ignition off.
2. Disconnect the C101 harness connector located behind the left side cylinder head.
3. Using a 12-volt test light, jump from the Ground circuit to the (K452) MDS Solenoid No.4 Control circuit in the C101 harness connector (PCM side).
4. Turn the ignition on.
5. Using the scan tool, actuate the MDS Solenoid No.4.

Does the 12-volt test light flash on and off?

Yes

- Go To 3

No

- Go To 7

3. MDS SOLENOID RESISTANCE




1. Turn the ignition off.
2. Measure the resistance between the Ground circuit and the (K452) MDS Solenoid No.4 Control circuit in the C101 harness connector (MDS side).

NOTE: It is important to follow the below temp/resistance values to ensure an accurate reading.





Is the resistance within an acceptable range?

Yes

- Go To 10

No

- Go To 4

4. GROUND CIRCUIT OPEN (MDS SIDE)




1. Turn the ignition off.
2. Gain access to the MDS Solenoid. Multiple Displacement Solenoid - Removal
3. Disconnect the MDS harness connector.
4. Measure the resistance of the Ground circuit between the C101 harness connector and the MDS 4 harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 5

No

- Repair the open in the Ground circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

5. (K452) MDS SOLENOID NO.4 CONTROL CIRCUIT SHORTED TO GROUND (MDS SIDE)




1. Turn the ignition off.
2. Measure the resistance between ground and the (K452) MDS Solenoid No.4 Control circuit in the MDS Solenoid 4 harness connector.

Is the resistance below 100 Ohms?

Yes

- Repair the short to ground in the (K452) MDS Solenoid No.4 Control circuit between the C101 harness connector and the MDS harness connector.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Go To 6

6. (K452) MDS SOLENOID NO.4 CONTROL CIRCUIT OPEN (MDS SIDE)




1. Measure the resistance of the (K452) MDS Solenoid No.4 Control circuit from the MDS Solenoid No.4 harness connector to the C101 harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Replace the MDS Solenoid. Multiple Displacement Solenoid - Removal
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Repair the open in the (K452) MDS Solenoid No.4 Control circuit between the C101 harness connector and the MDS harness connector.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

7. GROUND CIRCUIT OPEN BETWEEN THE C101 INLINE CONNECTOR AND THE PCM




1. Turn the ignition off.
2. Using a 12-volt test light connected to the 12 Volts, probe the Ground circuit in the C101 harness connector (PCM side).

Does the test light illuminate brightly?

Yes

- Go To 8

No

- Repair the Ground circuit between the C101 connector and PCM C2 harness connector.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

8. (K452) MDS SOLENOID NO.4 CONTROL CIRCUIT SHORTED TO GROUND (PCM SIDE)




1. Measure the resistance between ground and the (K452) MDS Solenoid No.4 Control circuit in the C101 harness connector (PCM side).

Is the resistance below 100 Ohms?

Yes

- Repair the short to ground in the (K452) MDS Solenoid No.4 Control circuit between the PCM harness connector and the C101 harness connector.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Go To 9

9. (K452) MDS SOLENOID NO.4 CONTROL CIRCUIT OPEN (PCM SIDE)




1. Measure the resistance of the (K452) MDS Solenoid No.4 Control circuit from the C101 harness connector to the PCM C2 harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Replace and program the Powertrain Control Module. Powertrain Control Module - Removal.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Repair the open in the (K452) MDS Solenoid No.4 Control circuit between the C101 harness connector and the PCM C2 harness connector.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

10. MDS SOLENOID 4




1. Turn the ignition off.
2. Remove the Intake Manifold. Intake Manifold - Removal
3. Reconnect the PCM C2 harness connector.
4. Turn the ignition on.
5. With the scan tool actuate the MDS Solenoid 4.

Can you feel and hear the Solenoid Actuating?

Yes

- Go To 11

No

- Remove the Solenoid (1) and check for any debris that may be blocking the oil passages (3) to the Solenoid. If the passages are clogged, clean the passages and replace the MDS Solenoid 1. If the passages are not clogged with debris, replace the MDS Solenoid 4.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

11. OIL PASSAGES RESTRICTED
1. Turn the ignition off.
2. Remove both Solenoids on Bank 2 of the engine block.
3. Remove the Bank 2 Cylinder Head.
4. Remove the lifters from the left engine bank.
5. Inspect the oil passages to the Solenoids and from the Solenoids to the lifters.

Are the passages blocked?

Yes

- Clean the oil passages as necessary. If the entire engine is restricted disassembly of the entire engine block may be necessary.

No

- Replace both sets of lifters if no other possible causes remain.