2012 Ram 3500HD 6.7L 4WD Auto
Have acquired this truck on the condition that it will go through batteries like a flashlight. Have 2 brand new batteries in it at the moment and they will be dead by morning. Once the new batteries were installed the CEL, service 4WD and traction control lights came on. Scanned and have multiple U codes. U011A - Lost comms with Exhaust Gas Sensor Module. U0102 - Lost comms with Transfer Case Control Module. U0126 - Lost comms with Steering Angle Sensor. U0212 - Lost comms with Steering Control Module. Aaaaaaannnnnnd....U0137 - Lost comms with Trailer Brake Control Module.
Have done a parasitic draw test and have found almost 600mA draw and minimal (like 50mA) is being drawn from aftermarket accessories, but there doesn't seem to be a fuse that will pinpoint the circuit the draw is coming from.
Want to lean towards a new TIPM, but not everyone has that kinda money kicking around. Any help would be appreciated, just looking for a direction to start heading in. TIA

 

Does your truck have an IOD fuse? (Ignition Off Draw) Might be as simple as a light staying on. Glove box, ashtray, under hood.....

As for the loss of comms.... Given the number of modules that are whining about it, gotta be something near the PCM.....

 

yes to the IOD, no to the lights, most have been removed because the previous owner was thinking the same thing. Will have a look at the wiring harnesses, have done wiggle tests to no avail, will open up any damaged harnesses and go from there I guess.

 

Is there an isolator between the batteries??