Allison problems

#21
OK good! While you're checking the trimmer valves, also take a look at the trimmer regulator. also take a look at the trim boost accumulator if it has one.
 
#23
Re: Allison problems

I have a 1993 American Eagle with MD3060 transmission and have the exact same problem. I worked on it all day yesterday trying to trace out wiring, etc. If I knew where any of this equipment (ECU, TCM, etc) was located, it would make things easier. I have all of the manuals and books and none show where the ECU is at and I'm not even sure what a TCM is. Having been an electrician by trade, I believe there is a loose ground somewhere. When I turn the key on, the shifter will flicker a little and then go out with no display except the "Do NOT Shift" light is on. If I wait and come back in ten minutes, the shifter will light up with an "N" for about 3 seconds and then go out again. After about three hours of looking at connections, etc., I turned the key and all was normal. Then I put it into Reverse and the shifter went blank and the "Do NOT Shift" light came on. Of course, did shift it back to Neutral and turned everything off. I went back 30 minutes later and it all worked again. This time it even shifted without going out and I managed to back it out and get it turned around and parked where it has an electrical source to plug into. Everything worked perfectly for many more attempts and I quit for the night thinking it might have been a ghost or something! Went out this morning and it worked great and I got it started and the air pressure built up. Just as the air pressure turned the buzzers off, the shifter started to flicker a little and then went off and on and the OFF! There are no diagnostic buttons on my shifter to even get a code and if there was a code, I wouldn't see it because the shifter is blank and appears to have no power. The nearest RV shop is over 50 miles from me and I am on a fixed income with very little cash on hand. Does anyone have a 1993 American Eagle, Cummins engine, Allison transmission, that knows the location of the ECU, etc.? I sent Spartan (the Chassis Manufacturer) an e-mail with the chassis model & serial number and ten minutes later, they sent me the wiring schematic of my motorhome. Now that's service! Unfortunately, it ends in with an arrow that says "ECU" that direction. I guess the chassis maker didn't wire the transmission.
I have a 1993 Pace Arrow 250hp diesel with MD3060 transmission and have almost the same problem. Has anyone had the same issues and if so, what was the fix? Any help with this problem would be appreciated. Thanks
 
Last edited:
#24
I have a 1993 Pace Arrow 250hp diesel with MD3060 transmission and have almost the same problem. Has anyone had the same issues and if so, what was the fix? Any help with this problem would be appreciated. Thanks
After reading about several people having this same issue, I was fairly sure the trouble was in my ECU. It turned out that was correct. I sent the ECU to Transmission Instruments in Flower Mound Texas 1-866-439-9779 and had the ECU repaired. They did a great job by the way. I got the unit back, installed it and yea! fixed! Thanks David V
 
#25
I recently brought a 1994 diesel pusher (1994 contentinal 3.8 with push button allison tranny). We went to the lake and the next morning the do not shift light was on and it would not go into gear. Finally was able to hit the drive the same time as the engine started and got it home. I went out several times and started it and it worked fine then the next time the do not shift came on the display on the push button panel flickered a little. I took the unit out and had it checked out and was told it was fine but there was a code for a power interuption. Put it back in and it worked great. I went out and drove it around yesterday all was well. Went out this morning and it is dead there is no power to the push buttons not a fliker. Sometimes in starting the engine I can turn the key but it does nothing. If I do it several times it starts. My senses tell me its a relay or something.

Any thoughts or ideas would be appreciated.
I agree with the first reply you got. Low Power to the TCM will give you this exact problem. After 2200 miles of intermittent similar problems, two towing jobs and Two service calls, Technician found low voltage on the IGNITION ON line. could not find the point of loss so he wired around it and Waa Laa, next 35000 miles were trouble-free (from this problem).
 
Top