Allison 2000 Range inhibitor

[Lorenzofoto]

Allison 2000 Range inhibited

I have 2002 International 3800 short bus t444e with Alison 2000. I got “range inhibited” and it won’t go into drive or reverse.

The day before the speedometers, tachometer, gas gauge, and trans temp stopped working in the instrument cluster (everything else worked). I watched videos and tried to solder it. Still didn’t work but next day they did. Then it stoped again and that’s when it went into limp mode . My question before I start throwing sensors as it. Can a bad cluster cause this? Or is it maybe getting bad signals from the wires going into the cluster? My fluid is topped off and fine. And I should know this but does a standard OBD2 code reader work on these? Where should I start my diagnosis? Also I can’t find the location of my PCM. Thanks for your time!

 

[ewo1]

First thing to do is to check the fuse for the TCM. It might be right at the battery or might be somewhere else.

On a friend of mine bus, we found the fuse under the brake pedal sandwiched between the bus body and bus frame.

 

[Lorenzofoto]

Thanks! I’ve been googling and trying to find its location but to no avail. It’s definitely not above the batteries. Thanks for trying to help.

 

[ewo1]

Thanks! I’ve been googling and trying to find its location but to no avail. It’s definitely not above the batteries. Thanks for trying to help.

what you need to do then is to visually & physically follow that power wire and somewhere along the line you might find that fuse. There is no sense in checking for anything else until you find that fuse.

Troubleshooting 101 = verify VCC - supply power

Where you batteries are, not the thick black and red wires, do you see any other wire on the positive terminals?

One should be for the ECM and the other for your TCM.

 

[cadillackid]

the TCM is often on the firewall.. it will have 2 connectors going into it .. its like a 4 inch by 6 inch silver box.



your ECM is the mionster size computer hanging off the passenger valve cover with really large connectors going to it..



if the TCM is elusive.. you can crawl underneath and follow the fat harness that comes out of the transmission.. a few of the wires will go off into other places. but the biggest part of the harness goes from the transmission directly to the TCM..

 

[musigenesis]

Sometimes you'll get the "Range Inhibited" light if you try to shift without having the brake pedal firmly pressed. I get this a few times a week in the bus I drive for work; the fix is to stomp the brake pedal, then shift to N and then shift to D.

 

[Flipmode-SKO]

I have a 2003; my TCM fuse was located about center on the firewall above the engine. From my battery compartment I have ~8ga set of wires going to power the ecm and TCM. Right around the bellhousing there’s a factory splice in the those power wires where the transmission harness taps into to get its power. My TCM is on the driver side frame rail next to the transmission.

 

[Flipmode-SKO]

Just reread your post; to answer the obd2 question: no it’s a j1939 setup. You would need a Nexiq or clone to read it running the Allison program. I went through this a while back(still going through it actually) and got the clone to make it work. Same thing with the software but it was a bit difficult for me to navigate that without technical help. Allison values their software quite a bit as their prices show…same for their service calls.