I have a Allison 4000 transmission that is not sending some info to my VMSpc. Talked with Roger and he did some troubleshooting and determined no info is being sent. Can someone point me to where the brain of transmission so I can try to clean the connections as a place to start. I get the transmission temp but no retarder temp, gear indication, economy indication. Just would like everything to work if possible. Haven't had a chance to go to talk to an Allison shop yet. Hope it is something I can fix so my wallet won't suffer. My coach budget has taken a beating this year.
Thanks
Keith
Keith,
If you look first in the basement mounted on the wall or ceiling behind the HWH compressor. If not there then it should be behind the kick panel that runs from the steering column over to the drivers side wall. If hid here it will be mounted on the drivers side wall framing.
Here is a good pic. that George took as to where the ECU is if mounted in the basement and what you are looking for.
Flickering display on Allison shift pad (https://www.foreforums.com/index.php?topic=36206.msg343214#msg343214)
Here is a link to a pic if it is hid under the dash like ours is.
No crank, no start: 1995 M-11 in Plainview TX (https://www.foreforums.com/index.php?topic=31323.msg275770#msg275770)
Sometime in the '99/20 time frame is when they moved location so it will be like hunting Easter eggs.
Mike
Mine is in the wet bay above the water pump!
I found it, in the bay with the 12v compressor on the wall. Now I just need some time to take it apart and clean the connections.
Thanks
Keith
I will be very surprised if you find any corrosion problem on the pins. The connectors are VERY tightly sealed. In the two posts linked below, you'll see photos of our Allison ECU and the wiring harness connectors, taken when I had ours out for a rebuild. Yours should be similar.
No start, with Allison "snake eyes" (Problem Solved) (https://www.foreforums.com/index.php?topic=25783.msg205110#msg205110)
No start, with Allison "snake eyes" (Problem Solved) (https://www.foreforums.com/index.php?topic=25783.msg205167#msg205167)
Well if those are clean, and yes they are tight, any suggestions? I guess it's not really hurting anything but I'm kinda anal and like to have things working if they should... those 2 ?? on the VMSpc for the gear selection just stare at me going down the road.....
Keith
Maybe call Allison and see if there is a re-boot feature.
Pins seem to get surface corrosion. The instrument guy said work the plug ten times
Keep in mind coatings on pins on electronics are rated for a finite number of "wipes". Don't practice this method as "routine maintenance" or you will wear through the plating.
Don't know if he is familiar with this issue, but John is in Flower Mound, TX and is the guru on shift pads and Allison ECU's:
Transmission Instruments (http://www.transmissioninstruments.com/)
John is the one who recommended the multiple plug ins to me for my 97
Talked to John, he was no help for my problem
Keith
Guess Stewart and Stevenson, the Allison dealer up on I 10 just inside 610 on the east side of Houston is the next contact.