Transmission Control Module Programming

The transmission control module (TCU, or TCM) decides when and how an automatic or dual-clutch gearbox shifts. On many modern vehicles it is built into the gearbox itself as a mechatronic unit. A failed or uncoded TCU causes harsh or slipping shifts, limp mode, a gearbox warning on the dash, or a car that will not select drive at all.

Signs of a transmission module problem

• Harsh, delayed or flared gear changes
• Stuck in one gear or in limp mode
• Transmission or gearbox warning light, often with communication faults
• Problems that started after water damage, a jump-start or electrical work

Replacement and programming

A replacement TCU must be programmed to the vehicle and matched to the gearbox it is controlling. We program new units online with genuine manufacturer software and code them to the vehicle's specification.

Cloning a TCU

Where the original unit can still be read, we can clone its software and data onto a replacement on the bench or online. This keeps the original calibration and is often the quickest way to get the car moving again.

Adaptations and relearns

After a module replacement, a transmission repair or a fluid service, many gearboxes need their adaptations reset and relearned. Skipping this step is a common cause of poor shifting after a repair, so we complete it as part of every TCU job.

Mail-in for selected units

Selected modules can be posted to us from anywhere in Australia for cloning or programming on the bench. Not every module can be done this way, so send us the part number and we will confirm before you post anything.

Working on a Mercedes-Benz? See our Mercedes-Benz XENTRY online coding and programming service.

See all our module programming and coding services.