P0340: Camshaft Position Sensor Circuit Malfunction
High SeverityNot safe to driveIgnition
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.
What does P0340 mean?
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.
P0340 is a ignition-related diagnostic trouble code classified as high severity. When your vehicle's ECU detects this condition, it stores P0340 and illuminates the check engine light.
What are the symptoms of P0340?
If your vehicle has triggered P0340, you may notice one or more of these symptoms:
Check engine light illuminated
Engine cranks but won't start (no-start condition)
Intermittent stalling while driving
Rough running or misfires
Hard starting, especially when warm
Loss of power or hesitation
What causes P0340?
Here are the most common causes of P0340, ranked by how likely they are to be the culprit:
highFailed camshaft position sensor (internal circuit failure)
mediumDamaged or corroded wiring/connector at CMP sensor
lowSensor air gap too large (sensor moved or reluctor wheel damaged)
lowTiming chain stretch causing erratic signal (often with P0016)
lowFaulty ECU input circuit (rare)
Is it safe to drive with P0340?
No - address this immediately. May cause no-start, stalling, or intermittent shutdown. If the engine starts and runs, drive only short distances to a shop. If it stalls unpredictably, do not drive. Have it towed.
How do you diagnose P0340?
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?
Repair costs for P0340 vary depending on the root cause and your vehicle. Here are typical estimates:
Repair
Parts Cost
Labor Cost
Total Estimate
DIY Difficulty
Replace camshaft position sensor
€20–€80
€30–€120
€50–€200
Moderate
Repair wiring or connector
€5–€20
€40–€150
€45–€170
Moderate
Replace camshaft position sensor (OEM)
€40–€150
€30–€120
€70–€270
Moderate
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
P0340 on specific vehicles
P0340 behaves differently depending on your vehicle. Select your car below for model-specific causes, known issues, and adjusted cost estimates:
P0340 on Toyota Camry
Toyota Camry • 2007-2024
The CMP sensor on the Camry 2AR-FE is located on the cylinder head near the camshaft sprocket. It is a Hall-effect type sensor. Access is straightforward from the engine bay. Denso OEM sensors are reliable. Oil leaks from the valve cover gasket can contaminate the sensor connector.
What causes P0340 on a Toyota Camry?
Toyota CamryValve cover gasket oil leak contaminating CMP sensor connector
Toyota CamryStandard sensor degradation at 150,000+ km
P0340 on Honda Civic
Honda Civic • 2006-2024
The 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 Civic?
Honda CivicMagnetic pickup degradation on R18A at high mileage
Honda CivicConnector corrosion from underhood heat and moisture on 1.5T
P0340 repair cost for Honda Civic
Estimated costs for Honda Civic ownersadjusted lower than average due to Honda-specific parts pricing
Repair
Parts Cost
Labor Cost
Total Estimate
DIY Difficulty
Replace camshaft position sensor
€18–€72
€27–€108
€45–€180
Moderate
Repair wiring or connector
€5–€18
€36–€135
€41–€153
Moderate
Replace camshaft position sensor (OEM)
€36–€135
€27–€108
€63–€243
Moderate
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
P0340 on Volkswagen Golf
Volkswagen Golf • 2005-2024
VW uses Hall-effect CMP sensors on TSI/TFSI engines. On the EA888, the sensor is located at the back of the cylinder head and can be awkward to access. Oil leaks from the upper timing cover are a common cause of sensor contamination and connector corrosion.
What causes P0340 on a Volkswagen Golf?
Volkswagen GolfUpper timing cover oil leak contaminating sensor on EA888
Volkswagen GolfRear cylinder head mounting makes access difficult
P0340 repair cost for Volkswagen Golf
Estimated costs for Volkswagen Golf ownersadjusted higher than average due to Volkswagen-specific parts pricing
Repair
Parts Cost
Labor Cost
Total Estimate
DIY Difficulty
Replace camshaft position sensor
€23–€92
€35–€138
€57–€230
Moderate
Repair wiring or connector
€6–€23
€46–€173
€52–€195
Moderate
Replace camshaft position sensor (OEM)
€46–€173
€35–€138
€81–€311
Moderate
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
P0340 on BMW 3 Series
BMW 3 Series • 2006-2024
BMW 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 3 Series?
BMW 3 SeriesVANOS system interaction causing erratic CMP signal on N52/N55
BMW 3 SeriesTurbo plumbing access restrictions on N55/B48
P0340 repair cost for BMW 3 Series
Estimated costs for BMW 3 Series ownersadjusted higher than average due to BMW-specific parts pricing
Repair
Parts Cost
Labor Cost
Total Estimate
DIY Difficulty
Replace camshaft position sensor
€28–€112
€42–€168
€70–€280
Moderate
Repair wiring or connector
€7–€28
€56–€210
€63–€238
Moderate
Replace camshaft position sensor (OEM)
€56–€210
€42–€168
€98–€378
Moderate
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
Related diagnostic codes
These codes are often seen alongside P0340 or indicate related issues:
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.
