Your 68RFE Cummins is a great jack-of-all-trades transmission that might need tuning to get the most out of it while helping ...

Transmission Control Module (TCM) faults are not unknown on these early Mazda 3s. Symptoms usually involve erratic shifting, a failure to select gear at all and having the car go into limp-home mode.

GM has issued a service update to address an issue related to the transmission control module (TCM) in certain 2020 Chevy Silverado HD and GMC Sierra HD models.

From there, the aftermarket transmission control module (TCM), which is mounted in the car like any normal ECU, can control the shifting based on just a few easily inputted signals such as ...

A faulty or malfunctioning transmission can trigger the check engine light for a handful of reasons, including things like an overheating gearbox or issues with the transmission control module (TCM).