2014 RAM 1500 SLT 5.7L Eng VIN T
MDS Cylinder #1 Shutdown at Idle
The diagnostic scanner shows MDS #1 shutdown is always active and code P1411 is set.
The lock pin in the MDS lifter was not locking in and returning the lifter to normal operation, when the lifter was removed it was visible that the pin was not locked in or even visible. After the repair, the PCM removed power to the solenoid on its own. Even though there is nothing in the diagram that I can find, on this particular truck the PCM when detecting a failure to disengage the MDS on a cylinder, will lock that cylinder out electronically to prevent excessive clearance in the valve train.
Replaced the MDS lifter, allowing oil pressure from the solenoid to push the locking pin in place and free the lifter to collapse and regulate pressure to the valves.
SureTrack® is a powerful value-added feature available with select Snap-on diagnostics tools. It offers an exclusive combination of expert knowledge and detailed parts replacement records, all wrapped in an interactive community.
Want more? Click here for more information on using SureTrack.
Looking for diagnostic tools? Click here to request more information on Snap-on diagnostic tools.
New or Expired SureTrack users: Click here for authorization key instructions.