Mercedes-Benz Camshaft Position Sensor Replacement: Symptoms and DIY
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Need to replace your Mercedes-Benz camshaft position sensor? Following the procedures below, you will learn how to remove and install the camshaft position sensor. This guide will show step-by-step instructions with photos of replacing a Mercedes-Benz camshaft position sensor.
At a Glance
- Applies to most Mercedes V6 and V8 engines with four cam sensors, such as the M272 and M273.
- Passenger side sensors are easy; the driver side needs the power steering reservoir moved.
- Tools: E8 Torx with T handle, small flat screwdriver, rags.
- Fit one new O ring per sensor, lightly oiled, and remove the old one.
- P0016 or P0017 on M272 and M273 often means timing chain or balance shaft wear, not sensors; check cam timing first.
Replacing the camshaft position sensor on most Mercedes-Benz is relatively easy. The passenger side sensors are straightforward to replace. However, the driver’s side camshaft position sensors are more challenging and require removing the power steering reservoir. You can replace just the faulty sensor, but it is recommended to replace all four sensors simultaneously.
Symptoms
- A failing camshaft position sensor will start losing its ability to transfer data quickly. As a result, mismatched fuel delivery and ignition timing will cause your engine to sputter, accelerate poorly, lack power, stall, or fail to start.
- Check Engine Light will throw a P0016 or P0017 code via OBD-II Scanner.
Be careful with those two codes on M272 and M273 engines. P0016 and P0017 are crank to cam correlation codes, and on these engines they often mean a stretched timing chain or a worn balance shaft or idler sprocket, which is a far bigger job. Sensor circuit codes such as P0340 to P0349 or P0365 to P0369 point at the sensors themselves. With correlation codes, check the cam timing values in live data before buying sensors.
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What you will need
Parts
- New Mercedes Benz Cam Position Sensor
Tools
- E8 screwdriver with T handle
- Small flat-head screwdriver
- Micro-fiber towels or rags
Procedure
- Put the transmission in Park. Set the parking brake.
- Allow the engine to cool down.
- Pop the hood by pulling the hood release under the dashboard.
- Remove the engine cover and power steering fluid reservoir to access the cam sensors. You may find the procedure for this at our Mercedes-Benz power steering reservoir guide.
- Using an E8 Torx socket with a T handle, remove retaining bolts on intake and exhaust cam position sensors.
- Disconnect the electrical connectors using a flat-head screwdriver.
- Remove the electrical connectors and wires out of the way.
- Pull the cam position sensors out.
- Clean the cam position sensor slots using a towel to avoid oil leaks after installing new sensors.
- Lubricate the o-ring of each new sensor.
- Place new sensors, ensure only one o-ring on each sensor, and remove the old o-rings.
- Install retaining bolts for each sensor.
- Torque the bolts to specs.
- Reconnect electrical connectors to cam position sensors.
- Reinstall the power steering reservoir.
- Reinstall the engine cover.
Frequently Asked Questions
How does the cam position sensor work?
The Camshaft Position Sensor detects camshaft rotation and is mounted near the cylinder head so that the sensor is opposite to the timing rotor attached to the engine camshaft. The engine ECU detects the camshaft angle and performs cylinder recognition based on the signals detected by the camshaft position sensor.
What’s the difference between the camshaft and crankshaft position sensor?
The crankshaft position sensor is the main sensor for ignition timing and engine speed. The camshaft position sensor tells the engine control unit which cylinder is on its firing stroke, so injection and ignition can be synchronized, and on engines with variable cam timing it also confirms where each camshaft actually is.
How much does it cost to replace the camshaft position sensor?
To replace a camshaft position sensor, you can expect to pay anywhere from $95 to $200. Parts alone will run about $25 to $100. Labor costs will range from $70 to $100 for professional replacement. Expect to pay more if you have a luxury vehicle or have your local car dealership perform the replacement.
Check these troubleshooting and repair guides for more help on your Mercedes-Benz.
