P0340: the camshaft position sensor circuit has a fault
The camshaft position sensor tells the engine control unit exactly where the camshaft, the rotating shaft that opens and closes the valves, is at any instant, which the computer uses alongside the crankshaft signal to time each injection correctly. This code means the electrical circuit for bank 1's sensor isn't behaving the way the computer expects. It covers the wiring and connector as much as the sensor itself.
You might notice
- The engine may struggle to start, run roughly, or stall
- The engine warning light comes on
- camshaft position sensor
- — a sensor that tells the computer exactly where the camshaft is at any instant
- camshaft
- — the rotating shaft that opens and closes the engine's valves
- bank 1
- — the side of the engine that has cylinder number 1
What the code itself says
P0340 is a powertrain (engine, gearbox and drive system) code, and the 0 after the letter means it is a generic code with a standard meaning.
Grouped here as: Engine running, fuelling and misfires — Air metering, fuelling, ignition, misfire, idle, boost, knock, oxygen sensors and the catalyst, all working together in the running engine. That grouping is ours, to help explain the code. The code's official family is the letter at the start.
This page is generic. Your car isn't.
A code on its own only tells you what the sensor saw, not what's actually wrong — and that changes next to your other codes. Read this one together with the rest of your scan and we'll work out what's really going on.
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