01 2500hd tranny gauge issue

[caton1911]

Help! I am new to forum...here's my problem: transmission temp gauge shows hot but the fluid is actually not hot which causes tranny to go into limp/safe mode. I took to Allison repair facility, and they say tranny is fine, the fluid is actually at norml temp., cooler is fine and pressure switch is fine. Chevy dealer initially said instrument cluster is bad, so I changed it and it still does it.

I can only drive 30 miles or so before it gives me trouble...I am $900 into troubleshooting, but no one knows what's going on...

 

[20chevy04]

same issue im having just havnt replaced my cluster yet becuase i dont have money to get it fixed yet so idk if thats the problem

 

[THEFERMANATOR]

Help! I am new to forum...here's my problem: transmission temp gauge shows hot but the fluid is actually not hot which causes tranny to go into limp/safe mode. I took to Allison repair facility, and they say tranny is fine, the fluid is actually at norml temp., cooler is fine and pressure switch is fine. Chevy dealer initially said instrument cluster is bad, so I changed it and it still does it.

I can only drive 30 miles or so before it gives me trouble...I am $900 into troubleshooting, but no one knows what's going on...

When you say limp mode, is it going into 3rd gear or is it raising the shift points and keeping the converter locked up? Limp mode for a trans problem will give you 3rd and reverse only whereas an overheat should send it into a mode like tow/haul first. A simple check with a scan tool when this is happening will tell what is going on. As for your cluster, 01-02 clusters don't often fail like teh 03-05 clusters do. They go out every once in awhile, but not often. And a failed cluster shouldn't send you into limp mode as it is pretty much a 1 way device on teh vehicle bus whereas it only receives data and doesn't really send anything back for the ECM or TCM to use. You need to figure out what it is doing first thing.

 

[caton1911]

Limp/safe mode may not be correct term. The tranny seems to shift hard on downshift when stopping and takes a while to shift when starting...however, it shifts properly when gauge shows normal range.

 

[THEFERMANATOR]

Limp/safe mode may not be correct term. The tranny seems to shift hard on downshift when stopping and takes a while to shift when starting...however, it shifts properly when gauge shows normal range.

This sounds like the TCM is sensing an overheat in the trans. You need to have a scanner on it when it is doing it and see what the TCM is seeing, then check the actual temp of the trans fluid and see if they are the same. If it isn't, then you may have a bad pressure switch or a bad internal trans harness.