This is going to be a long story, so please be patient....


Tuesday last week I picked up my new 5th wheel, and they installed the Prodigy brake controller with it. On the way home, both the tow/haul and overdrive disable buttons worked properly, although my overdrive disable light has never lit up, but I know it works as the tranny shifts to 4th from 5th when I hold the button in. On Wednesday, I had my tranny fluid replaced along with both the filters. I noticed my problem today, coming home from the bay area, not towing anything, when I tried to enable the tow/haul - I got no light on the dash and nothing happened to the shift points. Just for the hell of it, I tried to disable the Overdrive, and got nothing again. This is the first time I have tried these buttons since I got the tranny fluid changed. I shut down and restarted the truck, then tried them again with no luck.


So here are my questions.......


1. Does the Allison tranny have some connection for the T/H and OD to work? In other words, could the shop who changed the tranny fluid have left something disconnected?


2. Is there a fuse for the T/H and OD functions? I looked in the manual with no luck.


3. Now that the Prodigy is hooked up, is the T/H and OD button only available when the trailer is plugged in?


4. Are the lights in the dash hard to change? I would like to get the OD Disable light to work again.


Sorry if these questions seem ignorant, I am lost when it comes to this stuff.


Thanks for any info.


HD


PS - My truck was originally manufactured for Canada. I know the Headlight auto off function is disabled, so I don't know if there is anything else different with the truck that might cause this problem.Edited by: HD4fun

1. don't know


2. don't know


3. Mine work at any time


4. don't know


Sorry I don't have any other answers for you but I thought I'd at least give you one of them.

Terrain Twister,


Thanks for the help. I'm leaning toward something not being connected at the tranny.


Anyone else out there have any info?

1. Does the Allison tranny have some connection for the T/H and OD to work? In other words, could the shop who changed the tranny fluid have left something disconnected? No. The T/H button is only a momentary switch that sends a signal to the BCM which sends the signal to the TCM. The TCM makes the adjustments to shifts, TCC apply, etc.


2. Is there a fuse for the T/H and OD functions? I looked in the manual with no luck. No, there is no fuse for that circuit. It is powered by the BCM.


3. Now that the Prodigy is hooked up, is the T/H and OD button only available when the trailer is plugged in? No, it should work all the time.


4. Are the lights in the dash hard to change? I would like to get the OD Disable light to work again. The T/H and OD lights are LEDs. If they need to be replaced, the whole cluster needs to be sent to an AC Delco service center. Most likely there is a problem in the switch or the circuit.

GMCSID,


Thanks for the reply. So it looks like I'll be making a trip to the dealer, although I'm a little nervous based on the amount of mods I have done to the truck. Does this sound like something that might be an easy fix, where I might be able to take somewhere else and it won't cost me an arm and a leg?


To be honest, there is NO one in this town who seems to have any idea how to work on this truck. The tranny shop was clueless, didn't even know there was an Overdrive disable button, and some of the other shops I have talked to tell me they're two years behind the technology. I don't want to believe I will be taking this truck to the dealer for every little problem. http://www.dieselplace.com/forum/smileys/Cry.gif


Anybody know a good shop around here? Even somewhere around Sacramento wouldn't be too far to make sure I'm getting quality work done.





One last thing......Could the Juice/Attitude have anything to do with this?Edited by: HD4fun