P1417
P1417-CYLINDER 7 REACTIVATION CONTROL PERFORMANCE
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 4 to 8 cylinder mode.
- Set Condition:
The MDS fails to disengage for cylinder 7.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.
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. PCM Verification Test
2. (K454) MDS SOLENOID NO.7 CONTROL CIRCUIT SHORTED TO VOLTAGE
Turn the ignition off.
Disconnect the PCM harness connector.
Disconnect the C101 harness connector.
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.
Turn the ignition on.
Measure the voltage on (K454) MDS Solenoid No.7 Control circuit in the appropriate terminal of special tool #8815.
Is voltage present?
Yes
- Repair the short to voltage in the (K454) MDS Solenoid No.7 Control circuit.
- Perform the POWERTRAIN VERIFICATION TEST. PCM Verification Test
No
- Go To 3
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 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 4
No
- Visually and Physically inspect the wiring harness between the C101 connector and the MDS Solenoid connector. Repair as necessary. If OK, replace the MDS Solenoid.
4. PCM CONTROL
NOTE: The DTC must not be active for the actuator test to operate properly, clear all DTC before continuing.
Turn the ignition off.
Reconnect the PCM harness connector.
Disconnect the C100 harness connector.
Ignition on, engine not running.
Using a 12-volt test light connected to the (Z904) Ground circuit, probe the (K454) MDS Solenoid No.7 Control circuit in the C100 harness connector.
With a scan tool, actuate the MDS Solenoid.
Does the 12-volt test light flash on and off?
Yes
- Go To5
No
- Replace and program the Powertrain Control Module.
Perform the POWERTRAIN VERIFICATION TEST. PCM Verification Test
5. MDS SOLENOID 7
Turn the ignition off.
Remove the Intake Manifold.
Turn the ignition on.
With the scan tool actuate the MDS Solenoid 1.
Can you feel and hear the Solenoid Actuating?
Yes
- Go To 6
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 7. If the passages are not clogged with debris, replace the MDS Solenoid 7.
- Perform the POWERTRAIN VERIFICATION TEST. PCM Verification Test
6. OIL PASSAGES RESTRICTED
Turn the ignition off.
Remove both Solenoids on Bank 1 of the engine block.
Remove the Bank 7 Cylinder Head.
Remove the Lifters from the right 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.
- Perform the POWERTRAIN VERIFICATION TEST. PCM Verification Test
No
- Replace both sets of lifters if no other possible causes remain.
- Perform the POWERTRAIN VERIFICATION TEST. PCM Verification Test