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 DTC




Is the DTC Active at this time?

Yes
  • Go To 2


No

2.MDS SOLENOID NO.4











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

Yes


No
  • Go To 3

3.(Z42) GROUND CIRCUIT OPEN






Does the test light illuminate brightly?

Yes
  • Go To 4


No

4.(K452) MDS SOLENOID NO.4 CONTROL CIRCUIT SHORTED TO BATTERY VOLTAGE







Is the voltage above 1.0 volt?

Yes


No
  • Go To 5

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






Is the resistance below 100 ohms?

Yes


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.




Is the resistance below 5.0 ohms?

Yes
  • Go To 7


No

7.PCM

NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.




Were there any problems found?

Yes


No