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lavamanz · 01-30-2019, 04:16 PM

Since first of October I’ve experienced sporadic display issues with my Allison WTEC III pushbutton touchpad/display. The symptom generally has occurred just after stopping when I go to put the transmission in Neutral. Of last 8-9 times we have travelled an hour or more the display has gone blank. If I press the Drive or Neutral the transmission goes in gear & operates nominally with the display blank. It eventually comes back but before it does the display will show the “cateyes@ on the touch pad and it will also show all segments lit when this occurs after shutdown. It seems like after sitting a couple days it’ll start up normal and go to N on the display after briefly showing the all segments lit momentarily.

I Was finally able to read the codes once it came back to a normal display, and the code came up as 23 16 which is “Shift Selector display line fault” So far I’ve disconnected the connectior at the touchpad & reconnected it and I’ve also disconnected the + and - battery leads and reconnected them. The code has now come back each time and I’ve cleared it. I know

I can send it to John at Transmission Instruments to check it out but I don’t won’t to miss a wiring, ground, issue. Has anyone had the opportunity to run across this problem on their coach?

LJowdy · 01-31-2019, 10:28 AM

Years ago, on a 1,000 mile trip home from St. Anthony's sand dunes in Idaho, I had a similar problem.

The Cat's eye symbol appeared and then disappeared on several occasion. In St. George Utah, I stopped for Diesel and after filling up, the coach wouldn't start. The starter wouldn't engage.

Eventually with the help of my roadside service and after 5 hours of trying to start the coach, it ran and I made to Las Vegas at 2:00 AM. The next morning I called Allison in Las Vegas and they suggested that if the coach would start to take it home and have it checked out more local to my home.

Ultimately and after 5 days of trying to find the problem, Colton Truck Terminal, (authorized warranty station) discovered, by accident, that the wire bundle from the gear shift selector was rubbing against the generator enough to wear away insulation and cause a short circuit

They repaired the wires, zip tied the wire loom so it didn't touch anything and the problem was solved.

lavamanz · 01-31-2019, 03:17 PM

Thanks, sounds like I need to look at the harness wires closely. It is interesting how my problem isn’t affecting the operation of the RV

LJowdy · 01-31-2019, 03:34 PM

My problem may not be the same as your's but it's a place to start looking.

BillandLiz · 01-31-2019, 04:45 PM

Hi I had the cateye problem and with some help from a retired Allison guy traced it to the low speed sensor mounted on the out put shaft side of the transmission. If I recall the sensor is a hall effect (magnet spinning) that generates a 5vdc milliamp signal that must travel to the front of the coach (trans ecm) to confirm a run condition. There is also a high speed sensor that works the same and can be a problem. The issue for me was the terminals at the sensor were corroded and once cleaned solved the problem. Hope this helps.