Camshaft Position Sensor

Replacement of the camshaft position sensor on the M275 6.0L BiTurbo V12 engine to restore proper engine timing signal and resolve fault codes or performance issues.

Warnings

Tools required

Parts

• Camshaft Position Sensor × 1 — A2759050100 or A2759050200 (verify bank location)
• O-ring seal for camshaft position sensor × 1 — Usually included with sensor

Preparation

1. Park vehicle on level surface and engage parking brake
2. Allow engine to cool completely (minimum 1 hour after last operation)
3. Disconnect negative battery terminal and wait 5 minutes for system capacitors to discharge
4. Use scan tool to document specific fault codes for camshaft position sensor
5. Note which sensor position has failed: right bank intake, right bank exhaust, left bank intake, or left bank exhaust

Procedure

1. 1

   Remove engine covers
   Remove the upper engine cover by pulling upward firmly on the rear section to release the rubber mounting grommets. Then remove any secondary plastic covers over the valve covers by releasing the clip fasteners. The M275 V12 has multiple layered covers that must be removed to access the camshaft area.
2. 2

   Access affected cylinder bank
   For right bank sensors, access is from the right side of the engine bay. You may need to remove the air intake components or ducts for better clearance. For left bank sensors, access may require removal of additional components depending on sensor position (intake vs exhaust camshaft).
3. 3

   Locate camshaft position sensor
   The camshaft position sensor is mounted on the front of the cylinder head near the timing chain end. It is a small cylindrical sensor with an electrical connector on top. Each bank has two sensors (one for intake cam, one for exhaust cam). Verify you have located the correct sensor based on your fault code diagnosis.
4. 4

   Disconnect electrical connector
   Press the release tab on the electrical connector and carefully pull the connector straight back from the sensor. Do not pull on the wiring harness. If connector is stubborn, gently rock it side-to-side while pulling. Inspect connector pins for corrosion or oil contamination.
5. 5

   Remove sensor mounting bolt
   Using a 10mm socket or E8 Torx socket (depending on bolt type), remove the single bolt securing the camshaft position sensor to the cylinder head. Place bolt in a secure location to avoid dropping into engine bay.
   Torque spec

   Camshaft Position Sensor10 Nm (7 lb-ft)
6. 6

   Extract sensor from cylinder head
   Carefully pull the sensor straight out from the cylinder head bore. The sensor may be held in place by the O-ring seal. If stuck, gently rotate while pulling. Do not pry against the sensor body or cylinder head. Use a magnetic pick-up tool if sensor falls into the engine bay.
7. 7

   Clean sensor bore and inspect
   Clean the sensor mounting bore in the cylinder head using electrical contact cleaner and shop towels. Remove any oil residue, debris, or old O-ring material. Inspect the bore for damage or metal shavings which could indicate internal engine wear. The bore should be clean and smooth.
8. 8

   Prepare new sensor
   Remove new camshaft position sensor from packaging and verify it matches the old sensor design. Ensure the new O-ring seal is properly seated in the groove on the sensor body. Lightly lubricate the O-ring with clean engine oil to ease installation and prevent damage during insertion.
9. 9

   Install new sensor
   Carefully insert the new camshaft position sensor into the cylinder head bore, ensuring proper alignment. Push firmly until the sensor seats completely flush against the cylinder head mounting surface. The sensor should slide in smoothly without binding. Do not force.
10. 10

    Install and torque mounting bolt
    Install the sensor mounting bolt and hand-tighten initially. Using a torque wrench, tighten the bolt to the specified torque value. Over-tightening can crack the sensor housing; under-tightening can cause sensor misalignment and false readings.
    Torque spec

    Camshaft Position Sensor10 Nm (7 lb-ft)
11. 11

    Reconnect electrical connector
    Clean the electrical connector with electrical contact cleaner if any oil or debris is present. Push the connector firmly onto the sensor until you hear and feel a positive click indicating the locking tab has engaged. Gently tug on the connector to verify secure connection.
12. 12

    Reinstall engine covers and components
    Reinstall all removed air intake components, ducts, and covers in reverse order of removal. Ensure all mounting grommets are properly seated and all clips are fully engaged. The engine covers should sit flush without gaps.
13. 13

    Reconnect battery and clear fault codes
    Reconnect the negative battery terminal. Using the Mercedes-Benz Star Diagnostic tool or compatible scan tool, clear all stored fault codes related to the camshaft position sensor. This ensures a clean baseline for verification testing.

Reassembly

1. Ensure all engine covers are properly seated and secured before operating vehicle
2. Verify no tools or materials have been left in the engine bay
3. Double-check that the electrical connector is fully engaged with an audible click

Verification

• Start the engine and allow it to idle. Listen for smooth operation without misfires or rough running
• Use scan tool to verify no camshaft position sensor fault codes return after 30 seconds of idling
• Monitor live data on scan tool to confirm camshaft position sensor signal is present and correlates properly with crankshaft position
• Test drive vehicle through various RPM ranges and loads to ensure proper sensor operation under all conditions
• Perform final scan after test drive to confirm no fault codes have returned
• Verify engine starts promptly on subsequent cold and hot starts over the next few days

Related trouble codes on this vehicle

Codes that commonly send this job to the bay — tap one for symptoms, causes, and diagnostic steps.

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