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HELP please. Trans issues

807 views 3 replies 2 participants last post by  jrmat1 
#1 ·
I have an 01 2500 hd. This is my first diesel and love it. I have three codes showing up...

P0700 malfunction indicator lamp circuit malfunction (TCM)

P1781 transmission control module (TCM) MIL request circuit

P0708 transmission range sensor circuit high input.

I just put a new NSBU which I was told was the same as the range sensor and since I just changed it, it's going to take some time to clear itself. That only seemed to fix part of the issue. I did get back the gear indicator square on the dash but still stays in, I believe, 3rd gear once I shift into drive. PRN all work but shift with a clunk when I shift in and out of D.

Will a new TCM fix my issue or should I save that money and go right for a new/rebuild?
 
#2 ·
I wouldn't replace TCM without first condemning it. I would find a diagnostic flow chart for the codes listed and do the proper test. You never want to replace parts because of codes alone. However, we all know certain codes are generally a known problem like an 02 heater circuit code. 99% of time, it will be an 02 sensor issue. I'm not sure your codes are cut and dry like that and proper diagnostics need to be performed to determine the root problem. Hope this helps.


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#3 ·
Thank you jrmat1. I dropped it off at a trans shop and they hooked it up to their scanner and figured out the order of appearance, cleared it, drove it, and everything shows to have the proper range and shifting normally and no codes returned. He was saying that sometimes it takes a bit for the computer to recognize a new part. Thank you for responding so quickly.
 
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