P3497

P3497-MDS RATIONALITY BANK 2





For a complete wiring diagram Refer to the Wiring Information.

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:
O2 sensor readings on Bank 2 side indicate a lean condition while in 4 cylinder mode. One trip fault.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceedingPre-Diagnostic Troubleshooting Procedure.

1. ACTIVE DTC

NOTE: Diagnose any Misfire DTCs before continuing.

1. Ignition on, engine not running.
2. With a scan tool, select View DTCs.

NOTE: Diagnose any Deactivation or Oil Pressure DTCs before continuing with this test.

Is the DTC Active at this time?

Yes

- Go To 2

No

- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Intermittent Condition Test.

2. MDS SOLENOID 4
1. Turn the ignition off.
2. Remove the Intake Manifold.
3. Turn the ignition on.

NOTE: The DTC needs to be cleared before actuating the Solenoid, if the DTC is not cleared, the Solenoid may not be allowed to actuate.

4. With the scan tool actuate the MDS Solenoid 4.

Can you feel and hear the Solenoid Actuating?

Yes

- Go To 3

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 passages and replace the MDS Solenoid 4. If the passages are not clogged with debris, replace the MDS Solenoid 4.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

3. MDS SOLENOID 6
1. With the scan tool actuate the MDS Solenoid 6.

NOTE: The DTC needs to be cleared before actuating the Solenoid, if the DTC is not cleared, the Solenoid may not be allowed to actuate.

Can you feel and hear the Solenoid Actuating?

Yes

- Go To 4

No

- Remove the Solenoid and check for any debris that may be blocking the oil passages to the Solenoid. If the passages are restricted, clean the passages and replace the MDS Solenoid 6. If the passages are unable to be cleaned out, replacing the engine block may be necessary. If the passages are not clogged with debris, replace the MDS Solenoid 6.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

4. OIL PASSAGES RESTRICTED
1. Turn the ignition off.
2. Remove both Solenoids on Bank 2 of the engine block.
3. Remove the Bank 2 Cylinder Head.
4. Remove the each pair of lifters for Cylinders 4 and 6.
5. 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. Powertrain Verification Test.

No

- Replace both sets of lifters if no other possible causes remain.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.