C15 acert mxs ecm wiring. 2006 KW

There is a relay(at least in my truck) in the inner part of the frame above the starter area that has a push button to reset it if all power is lost, mine had loose connectors and it should low voltage as I kept turning on power inside the cab, like the headlights, a/c blower motor, etc, and when it got around 12 volts, the truck just shutted of on the spot. That's why I mentioned Low Voltage to the ECM will shut the truck off

 

I really think pins 52 and 53 are battery power. Pins 65 and 67 are ground. Pin 70 is key power. But I am not looking at the diagram that's shooting from the hip and can't be sure. So if you are missing one or the other there please don't run a jumper to see if that fixes it lol

 

Snowman I found this thread you might want to look over. It is a bxs acert but should be similar to yours. Kurt has some good posts in there and one guy was saying check the same pins @wore out stated. Good luck

http://www.thetruckersreport.com/tr...rt-bxs-shuts-off-throws-no-codes-help.225719/

 

If the power feed and ground is not directly off the batteries look for it to come off a relay or breaker. Some KW,s had some in the battery box and there is one here thats in the left frame rail behind the cab.

 

@snowman_w900. Let me know if your still chasing that gremlin. I have a mxs block. I had the same issue I replaced the economy harness found a broken pin and couple wires down stream from ecm.

 

If I remember, you have a mxs. Dont compare to a bxs. Different ecm. Check relay in battery box you may have bumped a wire loose. Do you have the plastic covers on the plugs that go on ecm? If so pull them off and look at wires. They have a tendency to rub through wires. Either it is a bad connection or ecm issue.

 

You are correct Superhauler, the The BXS has a 70 pin engine harness. The MXS has a 120 pin harness.