Allison md 3060

[transpro0104]

I have an Allison MD 3060 behind a Cummins 8.3 in a Country Coach on a Gillig chassis. The keypad shift selector went blank while driving, trans went into neutral momentarily and the exhaust braake indicator light blinked on and off and the speedometer went dead. This happened several times, but then immediately started working normally. I was able to get code(s) (d1-2312) and ( d2 3500) initially which indicated a no voltage to ECU. After parking at home for several days, I tried to start the coach but now there is no display on the touchpad, and the start solenoid won't engage, indicating the ECU isn't sensing neutral. I've cleaned all the battery terminals, checked the solenoids, and haven't found the problem. Any suggestions from here?

 

[dbarton291]

Re: Allison md 3060

Do you have a wiring diagram, so you can check and see if the ECU is getting 12V when the ignition key is turned on?

 

[transpro0104]

Re: Allison md 3060

After studying the wiring diagram to the ECU, I traced the 12v ignition power which was OK, but had lost the constant 12v power, probably somewhere in a bulkhead connector which I could not find. The fix was a jumper from a 12v feed directly to the ECU (protected of course.)