P0340 What does it mean?
Can you drive, what causes it and how it shows.
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Common codes
P0340
Camshaft Position Sensor "A" Circuit (Bank 1 or Single Sensor)
The camshaft position (CMP) sensor signal is missing or implausible. The ECU uses CMP together with CKP to identify cylinder phase for sequential injection and coil-on-plug ignition; without CMP the engine may run on group injection or fail to start.
Can you drive?
“You can drive, but see a mechanic soon”. The engine may stall on the road or fail to start.
9,533trouble codes explained in plain words, free.
What causes it
The most likely cause comes first. Some you can fix yourself.
- 1Sensor failed
- 2Timing chain stretched, throwing off sensor timing
- 3Wiring fault
How it shows
Usually it shows like this.
- Check engine light on
- Power loss especially in mid-rpm range
- Possible rough idle or stalling
- Increased fuel consumption
In the app
Partly freeExplaining a trouble code is free: 9,533 codes, offline. With an adapter the app reads the code itself and tells you whether you can drive. A sample scan is free; unlimited scans come with VINARI+.
Common questions
What does P0340 mean?
P0340: Camshaft Position Sensor "A" Circuit (Bank 1 or Single Sensor). The camshaft position (CMP) sensor signal is missing or implausible. The ECU uses CMP together with CKP to identify cylinder phase for sequential injection and coil-on-plug ignition; without CMP the engine may run on group injection or fail to start.
Can I drive with P0340?
“You can drive, but see a mechanic soon”. The engine may stall on the road or fail to start.
What causes P0340?
Most often: Sensor failed, Timing chain stretched, throwing off sensor timing, Wiring fault.
How do I find out which code my car has?
Plug an ELM327 OBD adapter into the OBD-II port under the steering wheel and tap “Scan” in VINARI. The app reads the code, explains it and tells you whether you can drive.
Do I still need a mechanic?
Yes. The app tells you what is going on and how urgent it is; the final word belongs to the mechanic.
Other topics
Source: OBDex (CC0), VINARIUpdated 2 November 2026
