Mercedes 7-Speed & 9-Speed TCU Repair
Gearbox warning, harsh shifts or stuck in one gear? We diagnose and repair the transmission control unit (TCU) on Mercedes 7G-Tronic and 9G-Tronic automatics.
About this service
On the Mercedes 7-speed automatic (7G-Tronic, gearbox code 722.9), the transmission control unit sits inside the gearbox, on the conductor plate of the valve body. Because it lives in hot gearbox oil, faults in this unit can cause gear changes to go wrong even when the mechanical parts of the gearbox are fine.
We read the fault codes first, then work on the TCU and conductor plate. When the gearbox pan is off, we fit a new filter, pan gasket and gearbox oil on the same job. We also work on the TCU of the 9-speed 9G-Tronic.
What we do
- 7G-Tronic (722.9) TCU and conductor plate
- 9G-Tronic TCU
- Fault code reading and diagnosis
- New filter, pan gasket and gearbox oil fitted on the same job
Signs you may need this
Not sure? WhatsApp us the fault code and we’ll tell you.
Gearbox warning
A transmission warning or message appears on the dashboard.
Limp mode
The car stays in one gear and will not shift up.
Harsh or late shifts
Gear changes feel rough, jerky or delayed.
Gear display problems
The gear indicator flashes, is blank, or shows the wrong gear.
How it works
- WhatsApp us the details. Send your car model, chassis number and the fault code to 9893 1923. A photo of the scan tool screen or warning light helps.
- We check and advise. We tell you what we can do: repair your unit, or supply a recon, used or new one.
- Drop off or pick-up. Bring the car or part to us at Premier @ Kaki Bukit, or use our pick-up and delivery service.
- Fixed, with warranty. Your car is back on the road, and the repair comes with a 6-month warranty.
Questions
Which Mercedes gearboxes do you work on?
Do you change the gearbox oil too?
Is there a warranty?
Related articles
Mercedes 7G-Tronic (722.9) TCU Problems: Signs and Repair
How a gearbox control fault shows up on the Mercedes 7-speed, and why the fault code comes first.
Mercedes “Active Brake Assist Functions Limited”: What It Means
Why this message appears on a Mercedes dashboard, and when it is more than a dirty sensor.
ABS or brake light on?
WhatsApp us the fault code, chassis number and car model. We’ll tell you what we can do.