4X4 Transfer Case Control Module Problems

My 1999 Jimmy was acting like it was hesitating when I took off from a stop. My neighbor works for a dealer and diagnosed the problem for me with the help of some Tech II gaget. It appears that the Transfer Case Control Module was signalling the transmission that it was in 4LO and thus was shifting from 1st to 4th gear before I reached 35MPH. This made it feel like the engine was missing. I bought a use salvage yard module for $100(vs the dealer price of $380) and so far it seem to be working.
Does anyone know if this is a common problem? I called GM Parts line and was told these were on back order and most salvage yards seemed to not be able to keep them in stock!

My 1999 Jimmy was acting like it was hesitating when I took off from a stop. My neighbor works for a dealer and diagnosed the problem for me with the help of some Tech II gaget. It appears that the Transfer Case Control Module was signalling the transmission that it was in 4LO and thus was shifting from 1st to 4th gear before I reached 35MPH. This made it feel like the engine was missing. I bought a use salvage yard module for $100(vs the dealer price of $380) and so far it seem to be working.
Does anyone know if this is a common problem? I called GM Parts line and was told these were on back order and most salvage yards seemed to not be able to keep them in stock!


I was having the same trouble. The GM dealer diagnosed the problem as a bad Transfer Case Control Module and wanted $700 to fix it. I went to a salvage yard and got the part for $75. I hooked the new Control Module up and when I started the Jimmy the "Service 4X4" light came on. Did you have to do any reprogramming of the new controller or did you just hook up the wiring harnesses?

I was having the same trouble. The GM dealer diagnosed the problem as a bad Transfer Case Control Module and wanted $700 to fix it. I went to a salvage yard and got the part for $75. I hooked the new Control Module up and when I started the Jimmy the "Service 4X4" light came on. Did you have to do any reprogramming of the new controller or did you just hook up the wiring harnesses?

You shouldnt have to reprogram it, try clearing it, two ways disconnect the battery for 15 - 30 minutes then hook it back up and start it. If that does not clear it try, with battery connected, removing the 4wd and crt lp fuses for like a minute replace them and cycle the key from off to run to off 5 times. I have been reading on this for mine and these are the methods to clear the tccm as far as I know. If it still comes on I would say you have another issue to look at.

I was having the same trouble. The GM dealer diagnosed the problem as a bad Transfer Case Control Module and wanted $700 to fix it. I went to a salvage yard and got the part for $75. I hooked the new Control Module up and when I started the Jimmy the "Service 4X4" light came on. Did you have to do any reprogramming of the new controller or did you just hook up the wiring harnesses?
All I did was plug in the module and all worked fine. Perhaps I was lucky. There are some very knowledgeable folks in this Forum and perhaps they can help you.

I'm Having the same problem, and told the same as I'm hearing here. I will try a salvage yard to get the module. I'm sure its as easy as plugging the new one in, but where is it located? Thanks in advance.