The Quick Answer above is the generic definition. What follows is the model-specific detail for the Hyundai models that log P0340.
DTC/P0340·Hyundai
P0340 on Hyundai: Causes, Symptoms and Fix Cost
Quick Answer
High SeverityNot safe to driveHyundai
P0340 on a Hyundai 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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Hyundai i30
2007-2024On Hyundai engines (i30, Tucson, Santa Fe with the Gamma, Nu and Theta units), P0340 usually means the camshaft position sensor has failed or its connector and wiring are corroded, sometimes after an oil leak soaks the sensor. A failed CMP sensor causes long cranking and stalling, so check the sensor and its harness before suspecting the timing chain.
What causes P0340 on a Hyundai?
Beyond the generic causes listed on the main P0340 page, these are the patterns noted for Hyundai models:
Hyundai i30Failed camshaft position (CMP) sensor
Hyundai i30Oil-soaked or corroded CMP sensor connector and wiring
Hyundai i30Timing-chain stretch on high-mileage GDI engines altering cam timing
How to diagnose P0340 on a Hyundai 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 Hyundai? (EUR)
Estimated repair costs for P0340 in EUR, compiled across makes. Hyundai costs typically sit in the middle 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 · Hyundai
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