Another shift range inhibit....

Budneeds2beers

Aka Mike Honcho....
Aug 25, 2016
497
4
18
Cali
So on my way to Phoenix today i noticed the cruise control would downshift an it would slam into gear. Then i get stuck at a fatal accident in the desert so i put the truck into park. Then when we were signaled to go, nothing truck wouldnt shift into anything. I cycled the ignition and the shifter then truck went into gear. The shifter did feel kinda stiff to shift. When i made it to havasu I stopped for a few min and had the same issue but i noticed that this time when the trans would shift it would slam into gear and roll back. I applied the brake and then i felt it engage. I also noticed that the indicator flashes under reverse now and i get a range inhibit and it is in limp and will only go into first or sec. gear. So needless to say im stuck and have only basic hand tools. Tonight i crawled under it and checked nsbu connection and cleaned. Fallowed wiring looked for rub and breaks to no unveil. No codes on the dash and i dont have a scanner. I need help if anyone is around.
 

036.6turbo

Active member
Jan 17, 2014
747
92
28
The last time I had that issue, it was the seal at the rear of the trans. Trans fluid was leaking past it, into the transfer case. Sometimes the Allision would check low on fluid, the next day it was high.

I found the problem by pulling the fill plug on the T case, it was extremely overfull.

Not sure this helps.

Others have talked about the main wiring harness at the right rear of the trans. Pull the connector off, if there is trans fluid in it, the internal harness is bad.

Mine did have fluid, I changed the harness, but my issue persisted.

Good luck.
 

Budneeds2beers

Aka Mike Honcho....
Aug 25, 2016
497
4
18
Cali
Levels checked fine, color is good. I looked at the plugs and no oil seeping. I dont have a meter but anyone know a way to check ignition switch? It is a older (2004.5) truck with just under 250k...
 

Mike L.

Got Sheep?
Staff member
Vendor/Sponsor
Aug 12, 2006
15,681
233
63
Fullerton CA
Tech2 would tell you right away if voltage was low at the trans. Just because you don't have a CEL does not mean you don't have any codes.
 

Budneeds2beers

Aka Mike Honcho....
Aug 25, 2016
497
4
18
Cali
Well its working now. I blindly fixed it. I changed the ignition switch and now it works just fine. $40 and 15 minutes later i was back on the road. Thanks for any input and mike, i will be a future customer. Thankyou