Anyone who works with transmission control units on a daily basis will be familiar with this pattern: The Mercedes 9G-Tronic gearbox control unit (VGS-NAG3, 725 series) rarely fails without warning – gear-changing problems, jerking or a loss of power are the classic warning signs. Revonik repairs your control unit at circuit board level, in 2–4 working days and for up to 70 % less than a new part. No reprogramming is required after the repair – simply fit it in and carry on driving.
Typical fault patterns in the 9G-Tronic transmission control unit
- Gear-changing problems, jerky gear changes or rough gear changes
- Severe gear-shift shocks and jerky gear changes
- The engine stalling, particularly when setting off
- Fluctuations in engine speed whilst driving
- The gearbox won’t change gear or gets stuck in one gear
- It is no longer possible to move forward or change gear
- Error message on the instrument cluster or emergency mode active
Why the Revonik? Our technicians have been repairing Mercedes transmission control units for over 12 years – at component level, not simply by replacing them. The original unit is retained and the vehicle-specific coding remains stored.
- Up to 70 % cheaper than a new part from the manufacturer
- Plug & Play – no reprogramming required
- Repair within 2–4 working days of receipt of the device
- 24-month warranty on the repair work
Frequently Asked Questions
Will the coding remain intact after the repair? Yes. We repair the original unit at component level. The vehicle-specific coding remains fully intact – no reprogramming is required.
What happens if the control unit cannot be repaired? We will let you know once the diagnosis has been carried out and, in this case, will only charge the flat-rate diagnosis fee of €69.00 (including VAT). The unit will be returned to you on request.
How long does the repair take? A standard repair takes 2–4 working days from the date the device is received. An express option is available for standard faults (repair within 48 hours, plus €149.00 incl. VAT).
