[bikestuff]

Ditto on Richard’s idea on the fast idle switch. If Fast Idle Switch is on the transmission will not do anything. (I am repeating in case it got lost above).

Bill

[cfree3]

Richard:

Would it be possible to talk to you today to see if you could walk us through what to check at the override switch and/or relay that it is wired to?

If so let us know your phone number.

Thanks

[Richard]

Sure, we are back from hiking. My number is 817 223 2056. We have talked before, it may be in your phone.

[Richard]

Rick,

Here is a link that will walk you through how to read the error codes on the transmission.

https://cdn.mpparts.com/pdfs/Trans%20Codes.pdf

What error code(s) do you get?

[cfree3]

So after searching the internet for help on this subject I found a tread on a Foretravel forum where someone was having the same problem as we were and he found an Allison Service Dealer that could go into the ECU (computer) programming for the transmission and disable the inhibit parameter on wire #155. We had to drive 2 hours with our ECU in hand to someone that could actually do that. Took him all of 5 min. I will update when we know it solved the problem.

[Richard]

And for future searchers of this thread.

Here are two pieces of info that may help.
On my coach, 99 year, look at the second from bottom wire exit from the big silver HWH box. You are looking for two black wires that terminate in a double packard connector. Here are two pics, one of the connector, and one of the label which says PGTL Neutral Hold. Ignore all the colored tie wraps. That was my way of quickly identifying the gazillion connections to the HWH box when I sent it for repair.

       

On later coaches with HWH rooms, you are looking for wires labeled 9955 and 9961.

I did not take the time to unplug it, and figure if unplugging disabled the Neutral hold, or shorting it together disabled.

[cfree3]

We’re on our way!!

[Richard]

Woo Hoo !!!!!!!!

[Latitude 28]

Wonderful news! I have to wonder what happened to cause a working ECM to all of a sudden not work? Would a preemptive disabling the inhibit parameter on wire #155 be something to do?

[cfree3]

You never know when a slide out might jam up. You can try your override switch when your slides are out and see if you can get in gear. If so everything is working for you. If not then you may want to have that parameter for wire 155 disabled to be proactive. But then all safety mreasures are gone.