P0343 means the camshaft position sensor signal voltage is higher than the ECU expects. This usually happens when the signal wire is open (broken), the sensor coil has failed open, the connector has lost contact, or the signal wire has shorted to a 12 V power source. P0343 is the inverse of P0342 and points to wiring or sensor faults rather than mechanical timing problems.
DTC/P0343·Audi
P0343 on Audi: Causes, Symptoms and Fix Cost
Quick Answer
Moderate SeverityNot safe to driveAudi
P0343 on a Audi means the camshaft position sensor signal voltage is higher than the ECU expects. This usually happens when the signal wire is open (broken), the sensor coil has failed open, the connector has lost contact, or the signal wire has shorted to a 12 V power source. P0343 is the inverse of P0342 and points to wiring or sensor faults rather than mechanical timing problems.
Repair cost on Audi€31 - €438
What does P0343 mean on a Audi?
Audi A4
2008-2024B8 A4 with 2.0 TFSI sometimes logs P0343 after a heat-soak start. The cam sensor fails intermittently when hot and recovers when cold. Replacement with the updated part number is the proper fix; cleaning the connector alone often does not resolve the fault.
What causes P0343 on a Audi?
Beyond the generic causes listed on the main P0343 page, these are the Audi-specific patterns we see most often:
Audi A4Heat-soak intermittent open on 2.0 TFSI cam sensor
Audi A4Wiring chafe on harness clip near the cam adjuster
How to diagnose P0343 on a Audi with OBD2
Follow these steps to pinpoint the root cause of P0343:
- Read freeze-frame data and confirm whether P0343 sets at cranking, at idle, or only after warm-up. Heat-soak-only failures often indicate a degrading sensor
- Inspect the sensor connector for full seating and signs of oil or coolant intrusion
- Unplug the sensor and check resistance across its terminals if magnetic, or verify 5 V reference and ground if Hall-effect. An infinite resistance reading confirms an open coil
- Check continuity of the signal wire from the sensor connector to the ECU pin. An open in the wire produces P0343 even with a healthy sensor
- With ignition on and sensor unplugged, measure voltage on each pin. A constant 12 V reading on the signal pin indicates a wire shorted to power
How much does P0343 cost to fix on a Audi? (EUR)
Estimated repair costs on a Audi (Audi parts and labour typically run 25% 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 P0343 on Audi
These codes commonly cluster with P0343 on Audi vehicles:
FAQ: P0343 on Audi
What does cam sensor circuit high mean?
It means the ECU is reading a voltage on the cam sensor signal wire that is higher than design. This usually happens when the wire is broken, the sensor has failed open, or the wire has shorted to a 12 V source. The ECU cannot detect cam pulses, so the engine struggles to start or run.
Why does the engine eventually start but run badly?
Most modern ECUs have a backup mode that runs the engine on the crankshaft signal alone, with batch fuel injection instead of sequential. The engine starts but with degraded fuel efficiency, no VVT control, and reduced power.
Is P0343 always a sensor problem?
No. Wiring is just as common. Always test the wiring with the sensor unplugged before paying for a replacement sensor. A simple continuity check from the sensor connector to the ECU pin can save the cost of an unneeded sensor.
Can a recent cam cover service cause P0343?
Yes. Removing and reinstalling the cam cover can disturb the sensor harness, and an unseated connector or pinched wire is a common source of a sudden P0343 right after a service. Recheck connectors first.
Looking for the full P0343 reference (all makes, full diagnosis flow, complete repair cost matrix)?
See the main P0343 guideSkanyx · Audi
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