Detroit Diesel DD ECM and Controller Locations

To tune a Detroit Diesel DD the MCM, ACM and CPC must be couriered to J-Ball.

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Detroit Diesel DD ECMs can’t be programmed online so your MCM, ACM and CPC must be sent to J-Ball Electronics. To ensure the fastest turnaround we’ve created this article to help you locate and identify the three components you need to courier to us:

  1. MCM (Motor Control Module) – will be bolted onto the side of the engine (size: 11.5″ wide x 8″ deep by 2″ tall).
  2. ACM (Aftertreatment Control Module) – the ACM looks just like the MCM and will be located near the emission control equipment on the frame rail or a mounting bracket. The ACM can be difficult to find and may even be located inside the frame rail in a hard to access location (size: 11.5″ wide x 8″ deep by 2″ tall)
  3. CPC (Common Powertrain Controller) – a VHS tape size black plastic box (size: 7″ wide x 4.5″ deep by 1.5″ tall) will be somewhere inside the cab and is often located under the dash or under the passenger seat (but this can vary from truck to truck).

Once you’ve located and removed the MCM, ACM and CPC call┬áJ-Ball Electronics toll-free at 1-855-326-8863 for important shipping instructions.

7 thoughts on “Detroit Diesel DD ECM and Controller Locations”

    • Hi Vernell,

      It seems to depend on the dealer if they require the truck when reprogramming a new CPC. Did your CPC fail? We’ve received numerous calls in the last few months from people trying to find CPCs because they are in short supply and on back order for several months.

    • Hi Sal, unfortunately we don’t sell harnesses for CPC or any other ECM related wiring. We tune ECMs, can’t even think if anyone aside from the dealership or a salvage yard for replacing wire harnesses.

    • Hi Dan,

      Unfortunately there is no way that we are aware of to track the CPC. If someone tries to use the CPC without having it VIN matched to the truck they are going to have a Check Engine Light. We don’t know if you can drive indefinitely with this CEL or if it escalates to a derate at some point.

      Authorized Detroit Diesel dealers will require proof of purchase of the vehicle for the VIN stored in the CPC to perform the VIN sync, at least that’s the process we’ve been through a few times lately with replacement CPC modules.


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