Mercedes Start/Stop Not Working

There may come a day when the Start/Stop function on your Mercedes-Benz no longer works. This article reviews possible causes that can prevent you from starting the engine with the Start/Stop button.

In case of an emergency

To get your Mercedes started manually, grab the Start/Stop button and pull it out. Make sure the transmission gear is in Park  (you should see the P gear on the dashboard) and you are pressing the brake pedal. Insert the key into the ignition and start the car.

Possible Causes

Smart Key Fob Battery

A weak battery in the key fob is one of the most common problems that prevent the Start/Stop button from working. As the battery in the key start gets old, it will unlock/lock the doors, but it will not have enough power to send a signal to the car for the Engine Start function.

If your Mercedes push start does not work, change your key fob’s batteries first. Follow this guide to learn how to change the Mercedes key fob battery. 

Note that sometimes new batteries don’t solve the problem. This can be because the “new” batteries may have sat on the shelf of your local store for years and are also discharged. Check the production date on the battery packing before you install them.

Press the brake pedal.

Your Mercedes-Benz will not start when you press the START button without pressing the brake pedal. Only the dashboard lights will turn on. Make sure you are pressing the brake pedal firmly.

Vehicle is locked

If you are inside the car and have pressed the lock button on the keyfob, you won’t be able to start the car. Press the unlock button on the keyfob. This will unlock the car and allow you to start the engine with the Start/Stop button.

Interference

Mercedes Start/Stop engine function can also stop working when there is interference. This could happen if you are parked near high-voltage power lines or a TV or radio station.

Move to a new location and check if your Start/Stop is operating properly.

Further diagnostics

If none of the above tips didn’t get your Start/Stop function to work, you could check the fuse for the ignition start circuit. Also, check the brake light switch, as it can prevent the car from starting and is often the culprit if the ignition turns on but the engine doesn’t start.

If the fuse is good and the brake light switch is not the problem, the next step would be to diagnose the car with an MB OBD2 Scanner.

Also note that if you are getting a “key not recognized” message on the dashboard, try a different key. The key is not working or is the wrong key.

What is the Best Scanner to Use for Troubleshooting Mercedes-Benz Problems/Issues?

If your Mercedes-Benz is experiencing problems, the YOUCANIC full system diagnostic scanner can be an invaluable tool to help you troubleshoot issues. By connecting to your vehicle’s onboard computer, the scanner can read fault codes and provide information about any issues with your car’s engine, transmission, brakes, or other systems. The scanner can also perform diagnostic tests on various systems, including the ABS, airbag, and steering systems, which can help you pinpoint the root cause of any issues.

Not only does the YOUCANIC scanner provide diagnostic information, but it can also help you save time and money on repairs by allowing you to perform simple fixes yourself. For example, if you see the check engine light on, the scanner can help you diagnose the problem and determine if it’s a simple issue you can fix at home or if you need to take it to a mechanic. You can save time and money by avoiding unnecessary trips to the repair shop.

Overall, the YOUCANIC full system diagnostic scanner is a powerful tool to help you maintain and troubleshoot your Mercedes-Benz. Whether a DIY mechanic or a professional technician, this tool can help you diagnose and solve even the most complex automotive problems easily, saving you time and money on costly repairs.