I replaced the engine and since then I can’t get the mds to work I’m getting nothing out of all 4 of them. I checked the ohms and all 4 was between 9.3 to 9.5 and also tested the harness that connects them and it was getting power so I’m stuck. Any suggestions?
HemiBoyzz
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5,328 Posts
If MDS is not working and the car is not logging any MDS error codes, with the check engine light On, then MDS has been disabled in the engine tune. Does not matter if you have MDS lifters, solenoids, etc... if MDS has been disabled in the engine tune ... MDS will not be active.
When checking the ohm value of the MDS solenoids (measure the resistance between the ground circuit and the MDS solenoid control circuit; on the MDS side of the harness connector) and compare with the following table. Resistance will vary according to temperature.
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When checking the ohm value of the MDS solenoids (measure the resistance between the ground circuit and the MDS solenoid control circuit; on the MDS side of the harness connector) and compare with the following table. Resistance will vary according to temperature.
.
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5,328 Posts
The MDS system is failing to deactivate the cylinders (transition from 8 cyl mode to 4 cyl mode). Reason can be electrical or mechanical. There's two codes for each cylinder for deactivation problems. Example: Cyl-1 has P3401 and P3402
P3401 is set when the Powertrain Control Module (PCM) recognizes an open or shorted condition with the Solenoid Control circuit.
P3402 is set when the MDS fails to engage (deactivate) for cylinder 1.
P3401 can be the control circuit shorted to battery voltage, shorted to ground, or open; or the ground circuit is open. It can also be the MDS solenoid but you said you installed new solenoids. All four solenoids share the same ground circuit so it may be the ground.
P3402 can be the same problems listed for P3401 but includes additional problems with low oil pressure (not able to push in the lifter locking pins) or the lifters themselves.
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P3401 is set when the Powertrain Control Module (PCM) recognizes an open or shorted condition with the Solenoid Control circuit.
P3402 is set when the MDS fails to engage (deactivate) for cylinder 1.
P3401 can be the control circuit shorted to battery voltage, shorted to ground, or open; or the ground circuit is open. It can also be the MDS solenoid but you said you installed new solenoids. All four solenoids share the same ground circuit so it may be the ground.
P3402 can be the same problems listed for P3401 but includes additional problems with low oil pressure (not able to push in the lifter locking pins) or the lifters themselves.
.
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5,328 Posts
If you're getting P3401 for Cyl-1 then I'm guessing the other MDS codes are P3425 (Cyl-4), P3441 (Cyl-6) and P3449 (Cyl-7).
P0013 is set when the PCM detects that the actual voltage of the Variable Cam Timing (VCT) Solenoid Control circuit does not match the intended state.
P0016 is set when the PCM detects that the deviation between the camshaft position and the crankshaft position has exceeded the maximum acceptable value.
What P0013 has in common with the MDS codes is that they share the same ground circuit. The VCT solenoid is located under the intake manifold in front of the MDS solenoids (attached to the VCT phaser assembly)
P0016 may be getting set because of P0013.
Check the wiring harness/connectors and ground connections.
![Image]()
VCT electrical connector (1)
VCT solenoid (3)
![Image]()
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P0013 is set when the PCM detects that the actual voltage of the Variable Cam Timing (VCT) Solenoid Control circuit does not match the intended state.
P0016 is set when the PCM detects that the deviation between the camshaft position and the crankshaft position has exceeded the maximum acceptable value.
What P0013 has in common with the MDS codes is that they share the same ground circuit. The VCT solenoid is located under the intake manifold in front of the MDS solenoids (attached to the VCT phaser assembly)
P0016 may be getting set because of P0013.
Check the wiring harness/connectors and ground connections.
VCT electrical connector (1)
VCT solenoid (3)
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