A faulty crankshaft position sensor (CPS) is a grave issue. Your Mercedes could very easily stop running. In this article, we’ll explain why this is so. We will also touch upon why this critical component could fail and how to tell if you have a faulty CPS. We’ll give you some pointers on what you should look out for and what to do in case of a failure.

What is a Crankshaft Position Sensor (CPS) and What Does It Do?

The crankshaft position sensor (CPS) is an extremely important part of your car, as it monitors critical data from the crankshaft and relays it to the engine control module (ECM). Without this little component, modern cars would not be able to run. First, we need to understand what a crankshaft is.

• Crankshaft: All internal combustion engines (ICE) have a crankshaft. It is an exceptionally fatigue-resistant piece of metal inside the engine that is connected to the engine’s pistons. The pistons move up and down in a linear motion, while the crankshaft moves rotationally. It receives the linear motion power and converts it into rotational motion power, which is distributed throughout the vehicle.
• Crankshaft Position Sensor (CPS): The CPS is a compact electronic gadget that is attached to the crankshaft. Its job is to monitor the motion and position of the rotating crankshaft and send that data to the onboard computer of your car. There is a magnet inside the sensor that enables it to know the position of the crankshaft. Once the computer receives the data, it analyzes this information and regulates the different engine functions, such as speed, fuel injection, ignition timing, and more.

Why do Crankshaft Position Sensors Go Bad?

There could be several reasons the CPS of your Mercedes could malfunction. Some typical reasons are listed below.

• Damaged Sensor: Overheating can cause the sensor to fail. In this case, your only option is to replace it.
• Faulty Wiring: Often, the wires become loose or frayed, causing communication between the sensor and the onboard computer to be disrupted.
• Wear and Tear: The sensor magnet could slowly lose its strength, which would lead to inaccurate readings.
• Debris: Any kind of foreign matter, like dirt, debris, oil, etc., on the sensor, will block the sensor from properly reading or relaying vital information.

Symptoms That the Crankshaft Position Sensor (CPS) in Your Car is Not Working

These are some signs that you may have a problem with the crankshaft position sensor (CPS).

• Misfiring Engine: If the engine misfires, that means there is something not right with the engine. There could be several reasons, one being a damaged CPS. A professional mechanic will be able to find out the exact problem.
• Rough Idling: If your Mercedes jerks and lurches during idling, that could be a sign of a problematic CPS
• Stalling: Your car stalls during the ignition cycle or, worse yet, while driving. This needs to be checked out immediately to see if there is a problem with the crankshaft position sensor.
• Sluggish Engine: If you notice your Mercedes doesn’t respond promptly when you accelerate, that could imply an issue with the CPS.
• Bad Gas Mileage: It is not surprising you may experience poor fuel efficiency as a side effect of a failing CPS.
• Check Engine Light (CEL): If there is a CPS issue in your car, this light will definitely turn on. You’ll see it lit on your dashboard. Although, keep in mind the CEL may light up for other reasons too. A professional mechanic will be able to tell what is exactly wrong by reading the error codes your Mercedes is throwing. This is done by hooking up a scanner to your Mercedes, which reads and deciphers the error codes.

Driving With a Faulty Crankshaft Position Sensor (CPS)

It is a bad idea to drive around with a malfunctioning CPS. It is dangerous because you could stall in the middle of the road. You could also do irreparable damage to your engine, which is an immensely expensive fix. Bring your car to us so that we can help you with this issue.

At Woodinville Sports Cars, we are the European and import auto specialists. Let our trained mechanics help you keep your car in excellent running condition. Call us or book an appointment to visit us. We are in Washington, with locations in Bothell, Kenmore, Kirkland, Mill Creek, Monroe, Redmond, Snohomish, and Woodinville.