How a Faulty TCM Makes Your Mercedes Unsafe

If you’re a Mercedes owner, whether that’s a sedan, roadster, coupe, cabriolet, or SUV, you will already know that it is the perfect blend of luxury and performance that makes a Mercedes-Benz such a great drive. But, if you’re noticing your car’s performance lagging, acceleration is not as good as it should be, gear changes become rough and/or inconsistent, or you notice your vehicle is not as fuel efficient as it once was, these could be a sign that your car’s TCM is running into trouble. If your check engine light is also illuminated, it is a clear red flag that you should get your TCM checked as soon as possible.

What exactly is the TCM?

The TCM, or Transmission Control Module of your Mercedes is the electronic mechanism responsible for the regulation of your car’s transmission. The transmission, in very basic terms, is how your car transfers the power of the engine to the car’s wheels, making your car move.

If you imagine the TCM as the brain and the transmission system as the muscles, the TCM is busy collecting data from your car, relaying messages and making the necessary calculations to allow the automatic transmission to choose the best gear to engage to suit the specific circumstances. The TCM receives and interprets signals from the car about the throttle and brake positions, the transmission fluid, the turbine speed and other transmission elements and has the ability to send codes to alert the driver of any potential issues encountered by your car’s automatic transmission system.

Generally, the TCM remains quietly and efficiently working away in the background for the lifetime of your Mercedes, but if you are unlucky enough to run into problems with your TCM, these must be addressed promptly.

If your TCM becomes faulty, your car will ultimately not be able to change gears when required, which could cause further serious problems for your motor’s transmission system and lead to irregular gear shifting, which can potentially make your Mercedes unsafe to drive.

So how do you know if your Mercedes TCM is faulty? Here are the most common symptoms that you may encounter.

Common symptoms of a faulty TCM

• Erratic shifts in gear: If your Mercedes suddenly shifts into a different gear or into neutral unpredictably, it’s a sure sign your TCM is in trouble. In this scenario, your transmission could potentially shift into neutral without warning in any circumstances, even at high speeds. This symptom of a faulty TCM can prove dangerous and you should discontinue driving and bring your car to a motor mechanic immediately.
• Losing acceleration: If your Mercedes engine seems to roar loudly, while your RPM continues to rise without an increase in your actual speed when you accelerate, this is a sign that the transmission is struggling to shift into a higher gear.
• Trouble downshifting: If your Mercedes is struggling to drop down in gear, this can lead to dangerous problems that can cause your engine to over-rev. You will need to have your car towed into a service center if it will not downshift.
• Gears are stuck: In this scenario your gears can become fixed in one gear position or in neutral. Obviously, if you are stuck in park or reverse, this can also become problematic and require a tow.
• Fuel economy lowers: A faulty transmission control module can often manifest in a reduced fuel efficiency in your Mercedes, and this can be one of the indicators that it is time to get your TCM checked out.
• Check Engine Light: This one is obvious but is worth mentioning twice. Never ignore the check engine light on your dashboard. It could prove more costly to do so in the long run. The TCM can diagnose potential problems with your car’s transmission systems and send up a code to alert you of these. If your check engine light is illuminated in conjunction with any of the other above symptoms, the TCM could be encountering problems. Your best step is to take your motor to a garage for diagnosis and repair.

Driving your Mercedes with a faulty TCM is potentially dangerous and can be damaging to your car’s transmission system in the long run, so don’t delay. Get your TCM the help it needs today.

Euro Plus Automotive Can Fix Your Faulty TCM

Euro Plus Automotive, the trusted auto repair shop in Canoga Park since 1984, has highly skilled ASE certified technicians with Mercedes expertise on hand to diagnose and repair any issues with your car’s transmission control module. Call or visit Euro plus Automotive in Canoga Park, Woodland Hills, San Fernando Valley, Los Angeles County, CA. We look forward to earning your patronage!