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·Honda
P0340 on Honda: Causes, Symptoms and Fix Cost
Quick Answer
High SeverityNot safe to driveHonda
P0340 on a Honda 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 Honda€41 - €243
What does P0340 mean on a Honda?
Honda Civic
2006-2024The Honda Civic CMP sensor on the R18A is a simple two-wire magnetic pickup. On the 1.5T, it is a three-wire Hall-effect sensor located near the intake camshaft. Both are accessible without major disassembly. Denso or Genuine Honda sensors recommended.
What causes P0340 on a Honda?
Beyond the generic causes listed on the main P0340 page, these are the Honda-specific patterns we see most often:
Honda CivicMagnetic pickup degradation on R18A at high mileage
Honda CivicConnector corrosion from underhood heat and moisture on 1.5T
How to diagnose P0340 on a Honda 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 Honda? (EUR)
Estimated repair costs on a Honda (Honda parts and labour typically run 10% below 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 Honda
These codes commonly cluster with P0340 on Honda vehicles:
FAQ: P0340 on Honda
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 · Honda
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