Allison code list, tq. specs, and other info

[More Power]

Thanks for your informative post! Good stuff!

Jim

[fost2u]

i am reading codes saying that my shift solenoid "c" is malfunctioning? i took off the trans pan to replace but all shift solenids seem to be the same w no markings? how do i find out which one is "c" or the bad one? i am looking up into bottom of trany w truck on a lift facing the front of truck??? which one is "c" from left to right?------------- thanks mark

[77TransAm]

See the two larger solenoids that are side-by-side? Those are A and B. C is hiding up above them. If it looks like it's the hardest one to get to, that's because it is.

[hrsedrvr]

my 01 duramax is stuck in 4wd low electronic shift control hit the 2 or 4 high button and just clicks and flashes a couple times then goes back to low. showing a code U 1026

any ideas?

[crashz]

You'll have to check that specific code first. However, its most likely a transfer case issue, and a common problem on electronic shift transfer cases is the the encoder motor that shifts the case. But don't start throwing parts at it until you pin-point the problem. Other common issues with the transfer case are speed sensors, dash switches and sometimes the transfer case control mondule. The only "cheap" thing in that list is the dash switch and even then its about $70. The encoder motor is about $500 last time I checked.

[rashworth]

We have a 2002 Duramax automatic four wheel drive short wheel base 3/4 ton truck that we took to the shop to have a gasket or (seal) replaced with the transmission when we took it out of the shop and brought it home it started not shifting...the shift light would flash but would not go into gear...they reset the codes and it worked for a bit, but then started having problems again...they replaced the harness...shift sensor and I believe a couple other things, but the truck got worse and it don't shift at all know...they gave up on it. I spoke with a friend of mine, she said her truck did the same thing (not leaking transmission oil though) just not shifting and the mechanic said it was the solenoid in the transmission...I spoke to the mechanic that was working on the truck they indicated they did not look at this...any ideas...is this a good spot to start looking for problems, is there a way we can check them?
Thanks in advance for your help...

[tcat10001]

Could you please tell me what the problem ended up being on your chevy when this happened to you MINE IS A 02 DURAMAX 2500 HD