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Topic: Allison Keypad: Lost Reverse  (Read 683 times) previous topic - next topic

Allison Keypad: Lost Reverse

Today I started the move for underground electric and all seemed normal, but when shifting into reverse, nothing on keypad for Reverse. Neutral and Drive functions, as well as Mode. The temp is high thirties, level and good battery connections.

I tried restart without any Reverse response. Shot keypad? Any ideas? Thanks.
Paul & Kathleen
1995 U320c SE 40'
Build 4681 --Cummins M11 /17511
"That Irish Girl"
Red MINI " 40"

Re: Allison Keypad: Lost Reverse

Reply #1 –
Paul,

Try the hairdryer trick.  Aim a hairdryer at the Allison brain box for a few minutes to warm it up, then try it again.  Might help - can't hurt anything.

If that doesn't work, try warming up the touch pad with the hair dryer.

If that doesn't work, you can try unseating and reseating the electrical plugs on brain box and touch pad.

That's all I got...
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Allison Keypad: Lost Reverse

Reply #2 –
You might try disconnecting the chassis batteries and see if it will reset.
Bruce, Linda, and Macy
Zoey RIP 1/20/19
1999 U295 40' build #5400
2017 silver Jeep Wrangler, 1260 watts of solar on top
Moving around the country

Re: Allison Keypad: Lost Reverse

Reply #3 –
Chuck & Bruce—By the time I got my hair dryer ready to go, I hit the R button one more time: Bingo. I'm (temporarily) back in business. This concern won't fix itself I suspect, so I need to get after the replacement of a 22 year old pad.

Thanks for the rapid responses. More to come. Paul
Paul & Kathleen
1995 U320c SE 40'
Build 4681 --Cummins M11 /17511
"That Irish Girl"
Red MINI " 40"

Re: Allison Keypad: Lost Reverse

Reply #4 –
You may want to disconnect the ground from the chassis batteries and unplug the trans computer and key pad and inspect for anything like corrosion. A lot of times just unplugging and plugging connections will fix an issue.
Bruce, Linda, and Macy
Zoey RIP 1/20/19
1999 U295 40' build #5400
2017 silver Jeep Wrangler, 1260 watts of solar on top
Moving around the country

Re: Allison Keypad: Lost Reverse

Reply #5 –
My Alison Keypad did the same thing a couple years ago (just when cold).
I removed it and dismantled it, then cleaned the contacts with methanol and sanded the black pads with 1000 grit sand paper.
It has worked perfectly since, hot or cold.
Wyatt
96 U320 40 WTFE, build 4943
84 Toyota Supra towd
2015 Jeep Wrangler towd
Victoria, BC, Canada

Re: Allison Keypad: Lost Reverse

Reply #6 –
Quote from: Old Knucklehead –
This concern won't fix itself I suspect, so I need to get after the replacement of a 22 year old pad.
If you are fortunate, this was just a temporary one-time glitch.  OR, it might be a early warning sign of more serious trouble ahead.

You might check to see if any Allison trouble codes are stored.  For this procedure, see below:

Allison Transmission Codes Manual

Depending on what you find, plan your next move.  If, for any reason, you think some component might be failing, try these trouble shooting steps:

http://www.transmissioninstruments.com/troubleshooting.html

If interested in my long-winded tale of Allison woes, see the thread below.  Spoiler:  It DOES have a happy ending!

No start, with Allison "snake eyes" (Problem Solved)
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"