Truck came to my shop, it's a 97 2500 with a 02 lb7/Allison. Someone put this together and never got it to work. New owner messed with it and gave up and brought it to me. Truck runs fine, will backup fine, but when you put it in drive you can feel it kinda go in gear but won't drive forward, then after 3-4 secs it drops completely out of gear.
First it had communication issues, which iv fixed. Then I found it had a 03 tcm in it, I replace that with one from a 02. Fixed a few issues.
Had a 03 OS in the ECM, reflashed with a 02 Os.
It now has absolutely no codes in the TCM, and has 1 in ECM for fuel level sender, which isn't hooked up to ECM.
Iv been over all the wiring buddy did, and all is good.
Iv pinned out the entire trans harness, and wiring between ECM and TCM.
Verified power and grounds to each modual.
Replaced nsbu
Owner Replaced trans with a used unit, before he brought it to me, no change
Iv spent an hour looking at scanner and can't see anything weird, it knows what gear it's in. Has input and our speed readings
Iv driven it around yard in reverse to "spin the internals"
.
Iv done a stationary taps fast learn,
Nothing has changed anything.
I'll take any ideas
First it had communication issues, which iv fixed. Then I found it had a 03 tcm in it, I replace that with one from a 02. Fixed a few issues.
Had a 03 OS in the ECM, reflashed with a 02 Os.
It now has absolutely no codes in the TCM, and has 1 in ECM for fuel level sender, which isn't hooked up to ECM.
Iv been over all the wiring buddy did, and all is good.
Iv pinned out the entire trans harness, and wiring between ECM and TCM.
Verified power and grounds to each modual.
Replaced nsbu
Owner Replaced trans with a used unit, before he brought it to me, no change
Iv spent an hour looking at scanner and can't see anything weird, it knows what gear it's in. Has input and our speed readings
Iv driven it around yard in reverse to "spin the internals"
.
Iv done a stationary taps fast learn,
Nothing has changed anything.
I'll take any ideas
