The transmission control module decides when the transmission shifts, and when it fails the vehicle is stuck in one gear, shifts harshly, or will not move at all. TCMs are one of the modules we source most, and the two questions that decide the order are where it lives and whether it needs programming. Both depend on the vehicle.
Where the module lives
On many GM six-speed automatics from 2007 on, the TCM sits inside the transmission on the valve body, so replacing it means dropping the pan. On Ford, Chrysler, Nissan, Mazda and Mitsubishi vehicles it is usually a separate box under the hood or under the dash, which is a simple swap. Older GM and Ford transmissions have no separate TCM at all; the engine computer runs the transmission.
Programming
Most TCMs built after 2008 need to be programmed to the vehicle with the manufacturer's tool, and some need the transmission's adaptive values reset afterward. Some older units are plug-and-play with a matching part number. We check the exact vehicle and say on the quote whether a shop visit is needed.
Before you replace it
Low or burnt transmission fluid, a failing shift solenoid, or a broken wiring connector at the transmission set the same codes as a failed module and cost far less. A P0700 code alone means the TCM has stored a fault, not that the TCM has failed; read the transmission-specific codes behind it first.
Transmission Control Modules by make
- GMC — Yukon and Sierra 6L80 TCMs inside the transmission; a frequent order.
- Chevrolet — Silverado, Tahoe and Traverse TCMs; 6T70 units on Traverse and Equinox.
- Nissan — CVT TCMs on Altima, Rogue and Sentra, usually programmed to the VIN.
- Ram and Dodge — Ram and Grand Caravan modules, VIN-locked on 2009 and newer.
- Ford — Focus and Fiesta PowerShift TCMs, Explorer and F-150 PCM-controlled transmissions.
- Mercedes-Benz — 7G-Tronic conductor plates, which carry the transmission electronics and need coding.
Read before you buy
Transmission Control Modules FAQ
Yes when the part number matches and either the vehicle does not require programming or you have a shop that can program it. We state which applies before quoting.
No. The powertrain control module runs the engine and, on some vehicles, the transmission too. On vehicles with a separate TCM the two talk to each other, and a fault in either can show as a shifting problem.
That is limp mode, the transmission's self-protection when the module sees a fault. It can be the module, a solenoid, a sensor or the fluid. A scan tool reading the stored codes narrows it fast.