P1417
P1417-CYLINDER 7 REACTIVATION CONTROL PERFORMANCE
For a complete wiring diagram refer to: Electrical Diagrams
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 active and take place for cylinder 7.
Possible Causes
- (K454) MDS SOLENOID NO.7 CONTROL SHORT TO GROUND
- (K454) MDS SOLENOID NO.7 CONTROL OPEN
- (Z904) GROUND CIRCUIT OPEN
- INSUFFICIENT OIL PRESSURE ACTING ON THE LIFTER LOCKING PINS
- OIL PASSAGES RESTRICTED
- LIFTER
- MDS SOLENOID NO.7
- PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.
Diagnostic Test
1. ACTIVE DTC
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.
Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
2. MDS SOLENOID NO.7
Turn the ignition off.
Gain access to the MDS Solenoid No. 7.
Disconnect the MDS Solenoid No.7 harness connector.
Ignition on, engine not running.
Turn off all accessories.
Using a 12-volt test light connected to the (Z904) Ground circuit, probe the (K454) MDS Solenoid No.7 Control circuit.
With a scan tool, actuate the MDS Solenoid 7.
Does the 12-volt test light flash on and off?
Yes >> Go To 7
No >> Go To 3
3. (Z904) GROUND CIRCUIT OPEN
Turn the ignition off.
Using a 12-volt test light connected to the 12-volts, probe the (Z904) Ground circuit in the MDS Solenoid No.7 harness connector.
Does the test light illuminate brightly?
Yes >> Go To 4
No >> Repair the open in the (Z904) Ground circuit.
Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
4. (K454) MDS SOLENOID NO.7 CONTROL CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Disconnect the PCM harness connector.
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.
Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
No >> Go To 5
5. (K454) MDS SOLENOID NO.7 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 (K454) MDS Solenoid No.7 Control circuit from the MDS Solenoid No.7 harness connector to the appropriate terminal of special tool #8815.
Is the resistance below 5.0 ohms?
Yes >> Go To 6
No >> Repair the open in the (K454) MDS Solenoid No.7 Control circuit.
Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
6. 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 POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
No >> Replace and program the Powertrain Control Module per Service Information.
Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
7. MDS SOLENOID 7
Turn the ignition off.
Remove the Intake Manifold per Service Information.
Reconnect the Solenoid harness connector. Turn the ignition on.
With the scan tool actuate the MDS Solenoid 7.
Can you feel and hear the Solenoid Actuating?
Yes >> Go To 8
No >> Remove the Solenoid and check for any debris that may be blocking the oil passages to the Solenoid. If the passages are clogged, clean the pas sages and replace the MDS Solenoid 7. If the passages are not clogged with debris, replace the MDS Solenoid 7.
8. OIL PASSAGES RESTRICTED
Turn the ignition off.
Remove both Solenoids on Bank 1 of the engine block.
Remove the Bank 1 Cylinder Head per Service Information.
Remove the Lifters from the left engine bank.
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.