P0340 means the ECU is not receiving a valid signal from the camshaft position (CMP) sensor. The ECU needs this signal to time fuel injection and ignition. Without it, the engine may not start, may run rough, or may stall intermittently.
DTC/P0340·BMW
P0340 on BMW: Causes, Symptoms and Fix Cost
Quick Answer
High SeverityNot safe to driveBMW
P0340 on a BMW means the ECU is not receiving a valid signal from the camshaft position (CMP) sensor. The ECU needs this signal to time fuel injection and ignition. Without it, the engine may not start, may run rough, or may stall intermittently.
Repair cost on BMW€63 - €378
What does P0340 mean on a BMW?
BMW 3 Series
2006-2024BMW inline-6 engines (N52, N55, B58) have intake and exhaust CMP sensors. P0340 typically refers to the intake cam sensor. On the N52, the sensor is easily accessible on top of the valve cover. On N55/B48 turbo engines, the sensor may be partially obscured by turbo plumbing. Bosch sensors are OEM.
What causes P0340 on a BMW?
Beyond the generic causes listed on the main P0340 page, these are the BMW-specific patterns we see most often:
BMW 3 SeriesVANOS system interaction causing erratic CMP signal on N52/N55
BMW 3 SeriesTurbo plumbing access restrictions on N55/B48
How to diagnose P0340 on a BMW with OBD2
Follow these steps to pinpoint the root cause of P0340:
- Check for companion codes (P0016, P0341, P0345). P0016 alongside P0340 suggests timing chain issues rather than sensor failure
- Inspect the CMP sensor connector for corrosion, oil contamination, or bent pins
- Measure sensor resistance with a multimeter (compare to manufacturer spec, typically 200-2000 ohms)
- Check sensor supply voltage (usually 5V or 12V depending on type) with key on, engine off
- Inspect the sensor mounting for looseness and the reluctor wheel/tone ring for damage or debris
- If sensor and wiring test good, check for timing chain stretch as the root cause
How much does P0340 cost to fix on a BMW? (EUR)
Estimated repair costs on a BMW (BMW parts and labour typically run 40% above the average for this code).
Prices estimated as of May 2026. Costs vary by region, vehicle, and shop.
Related codes that often appear with P0340 on BMW
These codes commonly cluster with P0340 on BMW vehicles:
FAQ: P0340 on BMW
Can a bad camshaft sensor cause a no-start?
Yes. The ECU needs the CMP signal to time fuel injection. Without it, many vehicles won't start at all. Some will start using only the crankshaft position sensor but run very poorly.
Is P0340 expensive to fix?
Usually not. The sensor itself costs 20-80 euros and labour is 30-120 euros. Total 50-200 euros on most vehicles. The sensor is typically accessible on the cylinder head.
Can P0340 cause stalling while driving?
Yes. An intermittently failing CMP sensor can cause the engine to stall without warning. If your car stalls unpredictably, do not drive it. Have it towed.
What is the difference between P0340 and P0345?
P0340 is the camshaft position sensor on Bank 1 (or the only bank on inline engines). P0345 is Bank 2 (V6/V8 engines). Same type of failure, different sensor location.
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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