Engine Camshaft Position Sensor Guide for the 2001-2005 Mercedes-Benz C320
If your C320 is running rough, stalling, or won't start, the camshaft position sensor is a likely culprit and an easy fix.
- A failing camshaft position sensor on your C320 will cause a Check Engine Light, hard starting, stalling, and poor performance.
- For this specific part, it is strongly recommended to use an OE-supplier brand like Bosch to ensure reliability and avoid repeat failures.
- The sensor is located on the front, passenger side of the engine and is easy to replace with an E8 Torx socket, making it a great DIY job.
- Be careful not to confuse symptoms with a failing crankshaft position sensor, which typically causes the engine to stall only when hot.
Symptoms of a Failing Camshaft Position Sensor
A bad camshaft position sensor on a 2001-2005 C320 will usually make itself known through several distinct symptoms. You won't be left guessing for long that something is wrong with your engine.
Common Failure Symptoms:
- Check Engine Light: This is often the first and most common sign. A diagnostic scan will likely show codes like P0340 or P0341. 🎬 See how to diagnose sensor issues by testing connector voltage.
- Difficulty Starting: The engine may crank for a long time before it starts, or it might not start at all. This problem can get progressively worse.
- Engine Stalling: The car might stall unexpectedly while idling or driving, which can be a serious safety risk.
- Poor Drivability: You may experience engine hesitation, stumbling, misfires, rough idling, and a general lack of power during acceleration.
- Reduced Fuel Economy: Inaccurate sensor data can cause the engine to use more fuel than necessary.
Choosing the Right Aftermarket Sensor
When it comes to electronic sensors for German vehicles like your Mercedes-Benz, brand choice is very important. While saving money is tempting, a cheap, low-quality sensor can fail quickly, leaving you with the same problem and forcing you to do the job twice.
For the C320, it's highly recommended to use a sensor from an Original Equipment (OE) manufacturer. These are the companies that supply parts directly to Mercedes-Benz for factory assembly.
- Tier 1 (Best Choice): Bosch. Bosch is a well-known OE supplier for Mercedes-Benz. Choosing a Bosch sensor is the closest you can get to buying a genuine part from the dealer, but at a lower price. It's the safest bet for reliability and proper function.
- Tier 2 (Good Alternatives): Hella, Delphi, Vemo. These are reputable European brands known for making quality electronic components. They are generally considered reliable alternatives if a Bosch part is not available.
- Tier 3 (Budget Options): Brands like Dorman, Standard Ignition (SMP), and others fall into this category. While they offer a significant cost saving, their long-term reliability on a sensitive European engine can be a gamble. Owner and mechanic experiences suggest sticking with OE suppliers for critical sensors to avoid premature failure.
Installation and Known Issues
The camshaft position sensor on the M112 engine in the W203 C320 is located on the front of the engine, on the passenger's side (right side), just below the valve cover. It is held in place by a single E8 Torx bolt. The replacement is considered relatively easy and can be done by a DIY mechanic with basic tools in under an hour.
🎬 Watch this step-by-step guide to replacing the sensor yourself.Pro Tip: The plastic electrical connector can become very brittle over time due to heat. Be extremely careful when unplugging it to avoid breaking the clip. Also, make sure the old rubber O-ring comes out with the old sensor. If it stays in the engine, you must remove it before installing the new sensor to prevent oil leaks.
There are no specific recalls from the NHTSA for the camshaft position sensor on the 2001-2005 C320. However, there is a known Technical Service Bulletin (TSB) related to oil leaking from the camshaft adjustment solenoids and wicking into the wiring harness, which can sometimes be misdiagnosed as a sensor issue. It's wise to inspect the area for oil leaks when replacing the sensor.
| Part Type | Estimated Cost |
|---|---|
| New Aftermarket | $17 - $96 |
| New OEM (Dealer) | $63 - $250 |
| Shop Labor | $37 - $140 |
Frequently Asked Questions
Where is the camshaft position sensor located on my C320?
The sensor is on the front of the engine on the passenger's side (Bank 1), just below the valve cover. It is secured by one E8 Torx bolt. The M112 V6 engine only has one camshaft position sensor.
Can I drive with a bad camshaft position sensor?
It is not recommended. A failing sensor can cause the engine to stall unexpectedly in traffic, which is a significant safety hazard. You should get the vehicle inspected and repaired as soon as possible.
Do I need to reset the computer after replacing the sensor?
After replacing the sensor, the Check Engine Light may turn off on its own after a few drive cycles. However, it is best practice to use an OBD-II scanner to clear the fault codes from the engine computer's memory.
My C320 stalls when it gets hot. Is that the cam or crank sensor?
While both sensors can cause stalling, the symptom of stalling only when the engine is hot and then refusing to restart until it cools down is a classic sign of a failing crankshaft position sensor, not the camshaft sensor. 🎬 Learn the differences between camshaft and crankshaft sensor failures. The camshaft sensor failure is more likely to cause rough running, hard starting, and a persistent Check Engine Light.
Helpful Videos
Technical Specifications
OEM Part Numbers: A0041530028 A0041536928 A0031539728
This is a Hall Effect sensor with a 3-pin connector. It is held in place by one E8 Torx bolt and sealed with a rubber O-ring.
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The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- Mercedes-Benz C320: