P3449

P3449-MDS SOLENOID 7 CIRCUIT





For a complete wiring diagram consult Diagrams/Electrical.

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.







Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Initial Inspection and Diagnostic Overview.


Diagnostic Test


1. ACTIVE DTC
NOTE: Diagnose any Misfire DTCs before continuing.

Ignition on, engine not running.
With a scan tool, read DTCs.
Is the DTC active at this time?

Yes


- Go To 2


No


- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Checking For An Intermittent DTC
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test




2. CHECKING PCM CONTROL SIDE FOR THE MDS SOLENOID
NOTE: The DTC must not be active for the actuator test to operate properly, clear all DTC before continuing.





Turn the ignition off.
Disconnect the C100 harness connector.
Using a 12-volt test light, jumper from the (Z904) Ground Circuit and the (K454) MDS Solenoid No.7 Control Circuit in the C100 harness connector (PCM side).
Turn the ignition on.
With the scan tool, actuate the MDS Solenoid No.7.
Does the 12-volt test light flash on and off?

Yes


- Go To 3


No


- Go To 4




3. MDS SOLENOID RESISTANCE




Turn the ignition off.
Measure the resistance between the (Z904) Ground Circuit and the (K454) MDS Solenoid No.7 Control Circuit in the C100 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 12


No


- Go To 8




4. (Z904) GROUND CIRCUIT OPEN (PCM SIDE)




Turn the ignition off.
Using a 12-volt test light connected to the 12-volts, probe the (Z904) Ground circuit in the C100 harness connector (PCM side).
Does the test light illuminate brightly?

Yes


- Go To 5


No


- Repair the open in the (Z904) Ground circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test




5. (K454) MDS SOLENOID NO.7 CONTROL CIRCUIT SHORTED TO BATTERY VOLTAGE (PCM SIDE)




Disconnect the PCM harness connector.
Ignition on, engine not running.
Measure the voltage on the (K454) MDS Solenoid No.7 Control circuit in the C100 harness connector.
Does the voltmeter indicate voltage present?

Yes


- Repair the short to battery voltage in the (K454) MDS Solenoid No.7 Control circuit between the PCM harness connector and C100 harness connector.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test


No


- Go To 10




6. (K454) MDS SOLENOID NO.7 CONTROL CIRCUIT SHORTED TO GROUND (PCM SIDE)




Turn the ignition off.
Measure the resistance between ground and the (K454) MDS Solenoid No.7 Control circuit in the C100 harness connector.
Is the resistance below 100 ohms?

Yes


- Repair the short to ground in the (K454) MDS Solenoid No.7 Control circuit between the PCM harness connector and the C100 harness connector.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test


No


- Go To 7




7. (K454) MDS SOLENOID NO.7 CONTROL CIRCUIT OPEN (PCM SIDE)





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 (K454) MDS Solenoid No.7 Control circuit from the C100 harness connector to the appropriate terminal of special tool #8815.
Is the resistance below 5.0 ohms?

Yes


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


No


- Repair the open in the (K454) MDS Solenoid No.7 Control circuit between the C100 harness connector and the PCM harness connector.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test




8. (Z904) GROUND CIRCUIT OPEN (MDS SIDE)




Turn the ignition off.
Gain access to the MDS Solenoid.
Disconnect the MDS harness connector.
Measure the resistance of the (Z904) Ground Circuit between the C100 harness connector and the MDS harness connector.
Is the resistance below 5.0 ohms?

Yes


- Go To 9


No


- Repair the open in the (Z904) Ground circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test




9. (K454) MDS SOLENOID NO.7 CONTROL CIRCUIT SHORTED TO BATTERY VOLTAGE (MDS SIDE)




Ignition on, engine not running.
Measure the voltage on the (K454) MDS Solenoid No.7 Control circuit in the MDS Solenoid No.7 connector.
Does the voltmeter indicate voltage present?

Yes


- Repair the short to battery voltage in the (K454) MDS Solenoid No.7 Control circuit between the C100 harness connector and the MDS connector.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test


No


- Go To 10




10. (K454) MDS SOLENOID NO.7 CONTROL CIRCUIT SHORTED TO GROUND (MDS SIDE)




Turn the ignition off.
Measure the resistance between ground and the (K454) MDS Solenoid No.7 Control circuit in the MDS Solenoid No.7 harness connector.
Is the resistance below 100 ohms?

Yes


- Repair the short to ground in the (K454) MDS Solenoid No.7 Control circuit between the C100 harness connector and the MDS harness connector.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test


No


- Go To 11




11. (K454) MDS SOLENOID NO.7 CONTROL CIRCUIT OPEN (MDS SIDE)




Measure the resistance of the (K454) MDS Solenoid No.7 Control circuit from the MDS Solenoid No.7 harness connector to C100 harness connector.
Is the resistance below 5.0 ohms?

Yes


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


No


- Repair the open in the (K454) MDS Solenoid No.7 Control circuit between the C100 harness connector and the MDS harness connector.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test




12. CHECKING HARNESS CONNECTOR C101 AND GROUND CONNECTION G102




Inspect the C101 harness connector.
Ensure the Ground terminal and Control terminal are fastened securely into the connector and there are no signs of corrosion or damage.
Check wiring to terminal connection. Look for an internal broken wire under the insulation.
Inspect the G102 Ground for a tight, clean connection.
Were any problems found?

Yes


- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test


No


- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Checking For An Intermittent DTC
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test