Our reliable Mercedes-Benz transmission control module mend or replace service

We know if you have a bad transmission control module, you need it put right safely and quickly.

Same-day turnaround

Our technical know-how and large stock mean MercKeys can either fix your TCM so it’s as good as new or replace it the same day (in most cases), saving you time and money.

Courier service

We offer a postal service too, so if you live outside the Auckland area you can still send the part to us by post, and we will return it to you as soon as possible.

Quality that’s second to none

The transmission control module is the brain of your Mercedes-Benz’s transmission, telling it when to change gears and how fast to go. It’s an essential component which is why our technicians are fully trained and we only source parts from reputable suppliers.

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Some words from our happy customers

Being a Merc owner with a W202 97 C class c230, my old key was beginning to die a slow death until it packed up 2 days ago, at a shopping center. Not able to get back into the car, i asked the Merc dealership down the road to assist, and they told me a new key would cost 3900 and 3 weeks to arrive. With no such time on my hands, I found Merc keys and had such great customer service and assistance from them. 2 hours later my car was up and running with a new key. Thanks again.

Greg G.


What does a TCM do?

A transmission control module (or transmission control unit) is an electronic component typically used in automatic gearboxes to process information within the transmission.

How can I tell if my TCM is broken?

A major sign that your transmission control module may be faulty is if you’re having trouble accelerating or your Mercedes-Benz is slow to get up to speed.

Other indicators are if your vehicle gets stuck in neutral, jumps out of gear whilst you’re driving, or refuses to switch up or down gears.

This is generally accompanied by an increase in fuel consumption as the engine must work harder than usual, meaning a drop in fuel economy.

Is it essential to get my TCM fixed?

If you suspect a fault with your transmission control module, we recommend taking care of it as soon as possible. This will prevent further damage within the module, potentially saving you added expenses down the road. Also, there is a significant risk of it failing whilst you’re driving, affecting your ability to control the vehicle safely.

Our full guarantee

We're so confident of the quality of our electronic car and key repairs that we fully guarantee all our electronic parts and electrical repair work for one year.

Reach out to our team today.

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