Automatic Transmission Control Module problems of the 2011 Chevrolet Silverado 2500

The transmission control module (tcm) began acting erratic. At times the transmission will not shift but several times it has gone into park( with no warning) when slowing down causing the wheels to lock and the truck skids to a stop. I was nearly in 2 accidents when this happened. Both time I was hauling a load and caused the traffic behind me have to swerve to not run into me. In looking into the issue I found that in 2011 gm had put out a shop notice that they had a known problem with the tcm and they thought it might be caused by a non-oem fan belt causing electrical discharge that might impact the tcm. A second shop notice from gm stated that the issue was due to heat and since they has mounted the unit on the fan shroud it should be moved. But none of the shops I went to knew about these shop notices from gm. Thousands of tcms have failed but no recall. Gm has now greatly reduced production of replacement modules and the cost of a new tcm has gone from $400 to $5000 ( plus programing ) and a long wait time to get one. You can get one refurbished for $1200.

The vehicle started to shift on its own mostly between the upper gears even though terrain or load had not changed. At slower speeds the vehicle started to automatically shift into park and lock up the wheels. This caused a very serious risk of injury to me and the people behind me when it would lock up. After stopping the vehicle sometimes does not move when in drive. There are no warning lights took it to a shop and they checked it over. I was informed that there is a known issue with the electronic transmission control unit (tcm) for the allison transmission. The issue is with the location of the tcm. Gm has developed a new unit to replace the original tcm that is engineered to no be affected by this. But due to the demand gm has a back order on the new tcm. The cost to get a tcm has risen from $800 dollars to $5000 dollars if you can find one.

The contact owns a 2011 Chevrolet Silverado 2500. The contact stated that while his wife was driving at an undisclosed speed, she made a mid-left turn and heard a low sound coming from the engine. The contact then stated that as his wife depressed the accelerator pedal, the engine revved but the vehicle failed to respond. The service stabilitrak, abs, and check engine warning lights illuminated. The vehicle was towed to an independent mechanic where it was diagnosed that the transmission control module needed to be replaced. The vehicle was not repaired. The dealer was notified of the failure and the contact was informed that the parts to do the repair were on back order. The manufacture was notified of the failure and the contact was provided a case number but no further assistance was provided. The failure mileage was approximately 61,000.

My truck has been at a dealership since may 31st , 2022. It needs a tcm. While researching , plus calling aftermarket parts suppliers(auto zone and others) , and also calling auto recycling/salvages yards , there are zero tcm's available unless you get lucky at a auto salvage yard minutes after a wrecked truck shows up. There is a huge issue with the tcm's failing on these 10 year old trucks , and gm refuses to allow their supplier to make replacement tcm's. I have lost the use of my truck for almost 6 months at this point. I would also like to know how many other customers are waiting for a tcm.

The contact owns a 2011 Chevrolet Silverado 2500. While the vehicle was idling at a red light, the contact depressed the accelerator pedal, but the vehicle failed to accelerate. The contact had to place the gear shifter in park to restart the vehicle on several occasions. The stabilitrak and traction control indicators illuminated. The vehicle was taken to sands Chevrolet glendale (623-931-9331, 5418 grand Ave, glendale, az 85301) where it was diagnosed that the transmission control module failed and needed to be replaced. The vehicle was repaired. The manufacturer was notified of the failure, but did not assist. The approximate failure mileage was 77,000.

Transmission control module and egr valve needs replaced at 61,000 miles.