I have a 2013 Chevy Impala with close to 180k miles on it. The Chevy dealer did a diagnostic and came back with codes P0872 P0877 and P0879. The dealership is saying “tech checked for common issues and found the TEHCUM bc of possible torn membrane switches. Will need further diagnosis” My possible charges would be 300-400 to open up the Trans and possibly 800-1k for part if there are no other issues. My question is should I replace the module? Are there normally other issues that are associated with this problem? Is there anything else I need to research to protect myself from the dealership?
Thanks for your help.
Transmission Electrical Hydraulic Control Unit (...) TEHCUM
That's what GM calls the TCM when sold with the valve body on their 6 speed transmissions.
codes P0872 P0877 and P0879
GM won't sell you just the TCM with the pressure sensors integrated - go to someone that knows how to work on these.
But make sure they actually have a clue as to what they're doing, GM ain't the kind of company to make a reasonable transmission that would be easy to test, they won't label the parts as you'd expect, etc.
Although I can't find much info on the 6T70, on the smaller versions of the same gearbox - and there are a lot of nuances and it's a real pain to do it correctly with the required programing etc.
But if GM's TEHCUM replacement quote is similar to what the TCM costs, maybe just replace the whole TEHCUM with that 2 year GM warranty - these go out all the time due to millage and wear.
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Research NOT going to a dealership. You'll get ripped off.
