Mercedes-Benz Transmission Malfunction Stop

Mercedes-Benz vehicles such as GLA or CLA models will display a Transmission Malfunction Stop when the Engine Control Unit (ECU) detects a problem that could potentially damage the transmission.

Mercedes-Benz Transmission Malfunction Stop can be caused by:

• faulty transmission control unit (TCU) firmware,
• low changing system voltage,
• low transmission fluid level,
• faulty transmission,
• or faulty engine control unit (ECU).

In most cases, pulling over, turning off the engine, and waiting a few minutes will reset the ECU and clear the transmission malfunction error.

Symptoms

• Transmission Malfunction Stop
• Check the engine light on.
• Vehicle stuck on limp mode
• Transmission shifts to position N automatically.
• Transmission shifts hard between cars.
• Transmission lurches when placed in the Drive
• Clunk when shifting from P to D.

Reset Transmission

If restarting the engine doesn’t work, reset the transmission adoption values following the procedure below.

1. Turn the engine off.
2. Turn the key to position II. All dashboard lights will turn on, but the engine should stay off. You can accomplish this by pressing the start button twice without pressing the brake pedal.
3. Press the accelerator (throttle) pedal to the floor to activate the kick-down switch.
4. Hold the throttle pedal pressed down for 30 seconds.
5. Take your foot off the throttle pedal and turn off the ignition by pressing the start/stop button once.
6. Wait for ten seconds, then restart the engine.

If the transmission malfunction error message returns, have the vehicle diagnosed as soon as possible. Do not continue to drive with the transmission malfunction light on.

Mercedes-Benz constantly provides software updates to fix problems that cause the Transmission Malfunction Stop problem. If resetting the transmission doesn’t fix the problem, call the dealer to check if a software update is available for your transmission.

The next step in troubleshooting is to read the fault codes from the transmission control module. Reading the transitions module codes is easy; you can perform them at home. Follow this guide to learn how to read Mercedes-Benz fault codes. 

One good example of a multi-system scanner is the YOUCANIC Full Systems Scanner. This scanner can read and clear fault codes from all the systems in your Mercedes-Benz. It can also perform bi-directional tests, maintenance and repair resets, etc.

We hope you find the Mercedes-Benz Transmission Malfunction Stop guide helpful. Check these troubleshooting and repair guides for more help on your Mercedes-Benz.