2006 z71 shifts from 2wd to 4HI while moving

[dwest52]

While driving my suburban shufts from 2Hi to 4Ht. I have replaced the switch. I do not get any service 4wd message so I am reading no codes. I just had to replace the transmission.

 

[zora]

Did you replace the transmission yourself or a shop did it? This link explains how the TCCM system works and brings up the question of when the transmission was changed was the encoder changed or the TCCM? Do you have the diagnostic tools necessary to connect to the TCCM?

http://repairpal.com/transfer-case-control-module

 

[dwest52]

I had a shop replace the transmission, but the problem was happening before the transmission went out. I only have a cheap code reader and am reading no codes, nor am I getting any message like service 4WD.

 

[zora]

Your code reader sounds like it is for engines only, go back to the shop assuming they have the proper equipment to do more than just replace the transmission.