Error code on Allison 3000 in 2015 Dutch Star

[rg neumann]

We have 8000 miles on our motor home, the transmission symbol on dash came on and said check transmission. The error code, obtained by pushing "up" "down" buttons said transmission fluid 1 quart too high. Never added any fluid to transmission. Pushing buttons again said PO883 inactive, then PO 881 & PO 880 both inactive. No other codes displayed. An authorized Allison Transmission shop said there was a electrical fault somewhere but it might cure itself. Any thoughts as to what the problem is?

[Skip426]

Questions ?
When the light came on and the code was set , had you been stuck in traffic and idling for an extended time in gear ? Pulling a long grade ?
Is this the only time the light has come on.

[dbarton291]

Originally Posted by rg neumann

We have 8000 miles on our motor home, the transmission symbol on dash came on and said check transmission. The error code, obtained by pushing "up" "down" buttons said transmission fluid 1 quart too high. Never added any fluid to transmission. Pushing buttons again said PO883 inactive, then PO 881 & PO 880 both inactive. No other codes displayed. An authorized Allison Transmission shop said there was a electrical fault somewhere but it might cure itself. Any thoughts as to what the problem is?

Those codes all relate to a problem with the TCM power input signal. The TCM is detecting a large variation (4 volts or more) in input power.

[rg neumann]

These symptoms all occurred in our driveway as I was attempting to reorient the RV. Had recently returned from Cleveland (175 miles) during an exceptionally raining period. Yesterday, I started the RV and neither the "wrench" symbol on the console nor the icon on the dashboard came on. Could this all be due to moisture getting into a connection? A local Allison technician said it could be difficult to trace if the symptoms are no longer present. Will these symptoms result in a shutdown of the RV at some point in time?

[dbarton291]

Originally Posted by rg neumann

These symptoms all occurred in our driveway as I was attempting to reorient the RV. Had recently returned from Cleveland (175 miles) during an exceptionally raining period. Yesterday, I started the RV and neither the "wrench" symbol on the console nor the icon on the dashboard came on. Could this all be due to moisture getting into a connection? A local Allison technician said it could be difficult to trace if the symptoms are no longer present. Will these symptoms result in a shutdown of the RV at some point in time?

Yes, moisture could definitely cause what you saw, especially if there is a loose connection in the power feed to the TCM somewhere and moisture got in the circuit.

If it's a loose connection and it gets worse, or if it's a corroded connection and it gets worse, and the power fluctuation to the TCM gets below the minimum required input voltage to the TCM to function properly, it would go into limp mode.

The way I would look at it is, those codes are a warning that something is going on in there. Before I went on a long trip, I'd have the power circuit for the TCM looked at for loose connections, chafed wires, corroded terminals, etc. Just my two cents.


Just an old man story - Electrical intermittents can be hard to find. I bought a 2008 Corvette new. When I took it through a car wash, it would power down to three cylinders and the service lights would come on.
Drove it to the dealer, they let it sit out, it dried out and of course nothing was wrong. Must be my imagination.
I got out my Genisys scan tool and my service manual and drove to the car wash again. Same result. Drove immediately to the dealer with my scan tool plugged in and the service manual open to the circuit the trouble code identified. "now do you guys think you can fix it? Do I need to leave you my scan tool and service manual?" I had to apologize for being a smart aleck.
They found a loose connector in the throttle circuit underneath the battery right where water would drain from the lip around the hood.