LED Display

[CaptMark]

Sorry if this is a remedial question, we have been searching our manual collection as well as the internet...

We just purchased a 2012 Fleetwood 42P with 450HP Cummings and Allison 3000 transmission with automatic selector switch.

We did a 400 mile run on Friday and during that, the LED display at times showed 65, 61, 21 and 25.

We scowered the owners manual thinking that it may be throwing out an error code, but find no reference to those numbers.

Our display is two digit, it seems like the diag codes and error codes are longer.

The coach drove perfectly for almost 7 hours, so don't think we have a problem, but would like to understand things better.

Are the displayed numbers representative of a gear position?

We also have an economy button, which we have not engaged. We are seeing about 8MPG, is that average?

[R.Wold]

I believe you are seeing the forward range selections. Diagnostic codes are four digit and have primary and secondary codes (main codes and sub-codes), primary being a 2 digit code that gives you the general function, and secondary 2 digit giving the specific fault. When you looked these codes over you saw they don’t use the 2 digit “codes” you listed because these indicate your gear range selections. That would cause all manner of confusion.

Your ranges are the gears the transmission will use (Selected by the up and down arrows) unless you go under or over the rpm limits at which point it will decide you are in the wrong range and shift anyway. So 2-1 is locked between 1st and 2nd unless you exceed maximum limits. Same with 5-2, 6-1, and 6-5. Although they used to be displayed in the opposite order which I think made more sense. Guess it depends on the model.

The purpose is to keep the transmission from shifting through a bunch of gears you don’t want to use for the conditions. So for instance 5-2 would be used when you don’t need to shift into 1st to get started, and you don’t want it to upshift to 6th because you’ll be driving in hills and it would be constantly shifting back and forth (shift cycling). I don’t know why they don’t explain it this way in the manual, but there is probably a operators tutorial out there somewhere.

Here’s the only reference I found in the manual but there are probably more:

6* 5* 4* 3 2
Occasionally, road conditions, load, or traffic conditions will make it desirable to restrict automatic shifting to a lower range. Lower ranges provide greater engine braking for going down grades (the lower the range, the greater the braking effect).
The pushbutton selector utilizes arrow buttons to select individual forward ranges. Push the �� (Up) or �� (Down) arrow to the desired range. The digital display will show your choice of range. Even though a lower range was selected, the transmission may not downshift until vehicle speed is reduced (this prevents excessive engine speed in the lower range).
* Actual ranges available depend on programming by vehicle manufacturer.

And by the way, their engine braking discussion is a bit lacking as well. All it needs to say is that the engine brake depends on exhaust pressure so it works better at higher rpm when more exhaust is produced. So translated “lower ranges provide greater engine braking” means lower ranges produce higher rpm and thus more exhaust to create more back pressure.

The way they explain it is like a syllogism that’s missing the middle term.

And I’d say 8mpg is doing pretty good for a rig that size.

[Pigman1]

I ran an internet search and found https://truckmanualshub.com/allison-...ult-code-list/

Clicking on the 5th selection brings up https://drive.google.com/file/d/1ifle5lQCPbZk_9vv_zcIjYPxiFoNSs2h/view
which may be iof some help.

Although the numbers appear to be shift info, if your rig was not shifting when these came up, they are not gear selections or gear limits as might be normally expected.

[RKins]

I'll take a shot at this. You have the 2 digit display. When using the transmission normally the left digit is usually 6 and the right digit is the gear that the tranny has selected to use. Lets say you see a incline ahead, you could "down shift" by pressing the down arrow and you see the left digit change to 5 or 4 or whatever you want it to be in. The left digit shows the maximum gear it can shift to. The right digit will always display what the tranny is using and is usually equal or less than the left digit.

There is a caveat to this and is the "25" you typed above. When you have the exhaust brake enabled and lift your foot off the accelerator, the tranny will seek 2nd gear (left digit) (this can be programmed by Allison) and then you'll see the right digit try to get to 2nd and you'll feel the breaking happening as the tranny downshifts.


Economy mode delays the downshifts trying to save you fuel. You can try it on flat lands.

Hope this helps.