Diagnostic Test

WARNING: This page is about a different car, the 2005 Jeep Grand Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

1) ACTIVE DTC
Ignition on, engine not running.

With a scan tool, read DTCs.

Is the DTC active at this time?

Yes
1. Go To step 2).
No
1. Refer to INTERMITTENT CONDITION .
2. Perform POWERTRAIN VERIFICATION TEST .
2) MDS SOLENOID NO.1 CONTROL CIRCUIT

Fig 1: Checking Multi Displacement System Cylinder 1 Solenoid Control Circuit
Courtesy of DAIMLERCHRYSLER CORP.

Turn the ignition off.

Disconnect the MDS Solenoid No.1 harness connector.

Ignition on, engine not running.

Turn off all accessories.

Using a 12-volt test light connected to ground, probe the (K451) MDS Solenoid No.1 Control circuit.

Does the 12-volt test light illuminate?

Yes
1. Go To step 3).
No
1. Go To step 4).
3) (K451) MDS SOLENOID NO.1 CONTROL CIRCUIT SHORTED TO VOLTAGE

Fig 2: Checking Multi Displacement System Cylinder 1 Solenoid Control Circuit
Courtesy of DAIMLERCHRYSLER CORP.

Turn the ignition off.

Disconnect the C3 PCM harness connector.

Turn the ignition on.

Measure the volage on (K451) MDS Solenoid No.1 Control circuit in the MDS Solenoid No.1 harness connector.

Is voltage present?

Yes
1. Repair the short to voltage in the (K451) MDS Solenoid No.1 Control circuit.
2. Perform POWERTRAIN VERIFICATION TEST .
No

NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.
1. Replace and program the Powertrain Control Module per Service Information.
2. Perform POWERTRAIN VERIFICATION TEST .
4) MDS SOLENOID 1

Fig 3: Checking Multi Displacement System Cylinder Solenoids
Courtesy of DAIMLERCHRYSLER CORP.

Turn the ignition off.

Remove the Intake Manifold per Service Information.

Turn the ignition on.

With the scan tool actuate the MDS Solenoid 1.

Can you feel and hear the Solenoid Actuating?

Yes
1. Go To step 5).
No
1. 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 1. If the passages are not clogged with debris, replace the MDS Solenoid 1.
2. Perform POWERTRAIN VERIFICATION TEST .
5) 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
1. Clean the oil passages as necessary. If the entire engine is restricted disassembly of the entire engine block may be necessary.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Replace both sets of lifters if no other possible causes remain.
2. Perform POWERTRAIN VERIFICATION TEST .