P3425-MDS SOLENOID 4 CIRCUIT
For a complete wiring diagram Refer to Section 8W.
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:
When the PCM recognizes a problem with the Solenoid Control circuit. One trip fault.
| Possible Causes |
| (K452) MDS SOLENOID NO.4 CONTROL SHORT TO BATTERY VOLTAGE |
| (K452) MDS SOLENOID NO.4 CONTROL SHORT TO GROUND |
| (K452) MDS SOLENOID NO.4 CONTROL OPEN |
| (Z42) GROUND CIRCUIT OPEN |
| MDS SOLENOID NO.4 |
| PCM |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
Diagnostic Test
1. ACTIVE DTCIgnition on, engine not running.
With a scan tool, select View DTCs.
Is the DTC Active at this time?
Yes
- Go To 2
No
- Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2. MDS SOLENOID NO.4
Turn the ignition off.
Gain access to the MDS Solenoid No. 4.
Disconnect the MDS Solenoid No.4 harness connector.
Ignition on, engine not running.
Turn off all accessories.
Using a 12-volt test light connected to the (Z42) Ground circuit, probe the (K452) MDS Solenoid No.4 Control circuit.
With a scan tool, actuate the MDS Solenoid 4.
Does the 12-volt test light flash on and off?
Yes
- Replace the MDS Solenoid No.4.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No
- Go To 3
3. (Z42) GROUND CIRCUIT OPEN
Turn the ignition off.
Using a 12-volt test light connected to the 12-volts, probe the (Z42) Ground circuit in the MDS Solenoid No.4 harness connector.
Does the test light illuminate brightly?
Yes
- Go To 4
No
- Repair the open in the (Z42) Ground circuit.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
4. (K452) MDS SOLENOID NO.4 CONTROL CIRCUIT SHORTED TO BATTERY VOLTAGE
Disconnect the C1 PCM harness connector.
Ignition on, engine not running.
Measure the voltage on the (K452) MDS Solenoid No.4 Control circuit in the MDS Solenoid No.4 harness connector.
Is the voltage above 1.0 volt?
Yes
- Repair the short to battery voltage in the (K452) MDS Solenoid No.4 Control circuit.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No
- Go To 5
5. (K452) MDS SOLENOID NO.4 CONTROL CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Measure the resistance between ground and the (K452) MDS Solenoid No.4 Control circuit in the MDS Solenoid No.4 harness connector.
Is the resistance below 100 ohms?
Yes
- Repair the short to ground in the (K452) MDS Solenoid No.4 Control circuit.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No
- Go To 6
6. (K452) MDS SOLENOID NO.4 CONTROL CIRCUIT OPEN
CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.
Measure the resistance of the (K452) MDS Solenoid No.4 Control circuit from the MDS Solenoid No.4 harness connector to the appropriate terminal of special tool #8815.
Is the resistance below 5.0 ohms?
Yes
- Go To 7
No
- Repair the open in the (K452) MDS Solenoid No.4 Control circuit.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
7. PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.
Were there any problems found?
Yes
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No
- Replace and program the Powertrain Control Module per Service Information.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)