The Quick Answer above is the generic definition. What follows is the model-specific detail for the BMW models that log P0340.
DTC/P0340·BMW
P0340 on BMW: Causes, Symptoms and Fix Cost
Quick Answer
High SeverityNot safe to driveBMW
P0340 on a BMW is the Camshaft Position Sensor Circuit Malfunction code: the engine computer is not getting a valid signal from the camshaft position (CMP) sensor, which it needs to time fuel injection and ignition to the right cylinder. The most common cause is a failed CMP sensor itself. Typical symptoms are hard starting, no-start, or sudden stalling. A replacement sensor and labour usually runs about 40 to 180 euros.
Typical repair cost, all makes€45 - €270
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BMW 3 Series
2006-2024BMW inline-6 and four-cylinder engines (N52, N55, B48, B58) run intake and exhaust CMP sensors, and P0340 usually points to the intake cam sensor. On the N52 it sits accessibly on top of the valve cover, while on N55, B48, and B58 turbo engines it can be partly buried under turbo plumbing. Because BMW uses VANOS variable cam timing, a worn timing chain or VANOS solenoid problem can produce an erratic CMP signal that mimics a bad sensor. Bosch is the OEM supplier.
What causes P0340 on a BMW?
Beyond the generic causes listed on the main P0340 page, these are the patterns noted for BMW models:
BMW 3 SeriesVANOS and timing-chain wear producing an erratic CMP signal on N52/N55
BMW 3 SeriesTurbo plumbing restricting access on N55/B48/B58, raising labour
BMW 3 SeriesValve cover gasket oil leaks contaminating the sensor connector
How to diagnose P0340 on a BMW with OBD2
Follow these steps to pinpoint the root cause of P0340:
- Scan for companion codes (P0016, P0341, P0345). P0016 alongside P0340 points toward timing chain or cam timing issues rather than a simple sensor failure
- Inspect the CMP sensor connector and tip for oil contamination, corrosion, bent pins, or a loose lock tab
- Check the sensor harness for chafed, melted, or broken wires between the connector and the ECU, and wiggle-test for an intermittent fault
- With the key on and engine off, confirm sensor supply voltage (typically 5V or 12V) and a good ground at the connector
- Measure sensor resistance with a multimeter on magnetic types and compare to the manufacturer spec (often 200-2000 ohms); Hall-effect types are tested by watching the signal on a scope or scan tool while cranking
- Inspect the sensor mounting and the reluctor (tone) ring on the camshaft for looseness, damage, or debris that would distort the signal
- If the sensor, wiring, and reluctor ring all test good, check timing chain stretch and cam timing as the root cause
How much does P0340 cost to fix on a BMW? (EUR)
Estimated repair costs for P0340 in EUR, compiled across makes. Expect BMW parts and labour towards the upper end of each range.
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
Codes related to P0340
These codes are often seen alongside P0340 or point to related issues, on any make:
Looking for the full P0340 reference (all makes, full diagnosis flow, complete repair cost matrix)?
See the main P0340 guideSkanyx · BMW
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