The camshaft position sensor on a BMW 328i is mounted to the cylinder head near the timing chain cover. Its exact seat varies by engine code and generation, but you’ll typically find it at the top of the engine with a small connector plugged into a short wiring harness.
Engine codes and typical locations
E46 328i (M54/M52 engines)
In the E46 328i, the camshaft position sensor is mounted on the cylinder head, close to the timing chain cover at the top of the engine. It connects via a compact three-pin (or multi-pin) plug that leads toward the ECU. Access often requires lifting the engine cover and could involve tilting nearby components for clearance.
E90/E91/E92 328i (N52 engine)
For the N52-powered 328i, the camshaft position sensor is also mounted on the cylinder head but tends to sit toward the rear of the engine near the firewall. The sensor uses a small connector that may be partially obscured by the intake manifold, so you may need to remove portions of the intake plenum to reach it.
F30 328i (N20 engine)
In the F30 generation with the N20 engine, the camshaft position sensor sits on the front side of the cylinder head near the timing chain cover. It typically offers easier access from the top once the intake system is removed or loosened for clearance.
How to locate and access the sensor
To locate the CMP sensor on your specific car, start with the following general approach: open the hood, remove any engine covers if present, and visually scan the top of the engine where the cylinder head meets the valve cover. Look for a small plastic sensor with a short electrical connector and a two- or three-pin plug. Trace the wiring back toward the ECU or harness tree. If you cannot spot it, consult your vehicle’s service manual or a VIN-specific diagram, as exact placement can differ by model year and trim.
What to do if you can’t locate it
If the sensor isn’t easily visible, consider these steps:
- Check for nearby components that may obscure access (intake manifold, throttle body, or accessory brackets) and temporarily remove or loosen them as needed to gain a clear view.
- Compare your engine code with factory diagrams or a repair guide specific to your model year to confirm the exact location.
- If in doubt, contact a BMW technician or dealer to confirm the precise location for your VIN.
Summary
The camshaft position sensor on a BMW 328i is mounted to the cylinder head near the timing chain cover. Exact placement varies by engine code and generation (E46 M54/M52, E90/N52, F30/N20), but all versions place the sensor on the head with a small connector. For precise location, reference your VIN-specific service manual or diagrams, and consider temporarily removing related components (engine cover, intake parts) to gain access.