Your Mercedes offers you comfort and reliability. You have peace of mind that you and your family are always safe. If your car has a faulty PCM, it will affect the operating of your vehicle. If you recognize the symptoms of a faulty PCM, you should seek the services of a Mercedes repair shop to get the issue resolved. Let’s take a closer look.
What is a PCM?
The Powertrain Control Module (PCM) manages the engine, transmission, and other systems based on the information it receives from various sensors around your Mercedes Benz. It is one of the dozens of microprocessors on modern vehicles that run everything from the climate control system to the power windows. Older vehicles used to have a separate system that operated the engine called the Engine Control Module (ECM.)
A vehicle simply cannot function without a PCM, so it goes without saying that it is an integral part of the car and often referred to as the brain. If this fails, the car will be rendered inoperable.
7 Common PCM Failure Symptoms
- The check engine light is on: The check engine light can come on for a variety of issues. A professional will diagnose the code so you’re one step closer to getting your Mercedes If you have multiple warning lights flashing then seek immediate help.
- Your Mercedes won’t start or it starts roughly: Vehicles usually have a rough start during colder weather, but if the car does not start when you turn the key or has a jerk, then you should immediately get an appointment at a repair center. Even if it is not a PCM issue, this can lead to a costly repair if not treated quickly.
- Sudden loss of gas mileage: Some Mercedes models are known for their fuel economy. If you find that your vehicle unexpectedly has high fuel consumption, then it could be an indication of a Faulty PCM.
- Your Mercedes failed the emissions test: This is caused by a rich air/fuel mixture and is usually a result of a defective oxygen sensor or faulty injectors. So, if you fail emissions, have these components inspected and changed if necessary. You have a loose or leaking gas cap.
- The engine stutters or stalls: Although this could be the sign of a small issue, you rather err on the side of caution and get your car checked by our repair center.
- Erratic or random shifting: The problem will begin with hesitation when changing gears. This happens because of a faulty sensor or because water has seeped into your PCM. If left unchecked, it will then begin grinding or shaking when shifting gears. At this point, it is best to bring your Mercedes to our professionals who will correctly diagnose the problem.
- Receiving a PCM-related error code: The P0606 fault code means that there’s an error with your power control module.
Reprogramming the PCM
If the PCM is faulty, then a replacement is necessary. If there is a software issue, the fault will be rectified with a software update. The PCM uses software to control the systems in the vehicle. For example, it knows that when you’re driving up a steep incline and you need more power.
As with your laptop computer, downloading an update is an essential part of keeping your car running optimally. Mercedes manufacturers will sometimes release updates for your model. Bring your car to our professional mechanics to get the updates done correctly.
If you purchased a used PCM as a replacement, you will need to have it reprogrammed for it to be able to work with your vehicle. This is why it is best to avoid shadetree technicians and instead come to certified professionals who know Mercedes models inside and out.
The Best Repair Shop in Mountain View
Bavarium Autoworks is located at 2232 Old Middlefield Way in Mountain View, CA. When you visit our shop, we want your experience to be as positive as possible. We’re committed to providing you with the highest-quality services while also following all the guidelines and practices related to the COVID-19 pandemic.
Our ASE certified mechanics are equipped with the finest tools to service your Mercedes and get you back on the road as quickly as possible. Located in Mountain View, the mechanics at Bavarium Autoworks also help drivers from surrounding areas like Cupertino, Palo Alto, San Jose, Santa Clara, and Saratoga. Give us a call today to set up an appointment!