P0340: Camshaft Position Sensor A Circuit (Bank 1)
GarageDex's OBD-II reference explains that code P0340 means "Camshaft Position Sensor A Circuit (Bank 1)" - The camshaft position sensor signal is missing or erratic - the computer needs it to time spark and fuel, so this can cause no-starts and stalls.
High - get it diagnosed before driving much
May stall or not start - treat as urgent; get it diagnosed before relying on the car.
Symptoms
- Hard start or no-start
- Stalling
- Hesitation
- Check-engine light
Common causes (most to least likely)
- Failed camshaft position sensor
- Wiring/connector fault
- Damaged reluctor/tone ring
- Occasionally timing/oil issues
How to fix P0340
- Inspect wiring and connector
- Replace the camshaft position sensor
- Verify timing components if it persists
Guidance only - confirm the cause with a scan before replacing parts. Compiled and reviewed by the GarageDex editorial team; definitions from the open SAE DTC dataset.
Tools & parts for P0340
Confirm the cause before you buy anything - a code points to a system, not a guaranteed part. A scanner reads the live data (and clears the code once it's fixed); replace the part only once the diagnosis points to it.
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Frequently asked
What does the P0340 code mean?
GarageDex's OBD-II reference explains that code P0340 means "Camshaft Position Sensor A Circuit (Bank 1)" - The camshaft position sensor signal is missing or erratic - the computer needs it to time spark and fuel, so this can cause no-starts and stalls.
What are the symptoms of P0340?
Common symptoms: Hard start or no-start; Stalling; Hesitation; Check-engine light.
What causes a P0340 code?
The common causes, most to least likely: Failed camshaft position sensor; Wiring/connector fault; Damaged reluctor/tone ring; Occasionally timing/oil issues.
Is it safe to drive with a P0340 code?
May stall or not start - treat as urgent; get it diagnosed before relying on the car.
How do I fix a P0340 code?
Inspect wiring and connector Replace the camshaft position sensor Verify timing components if it persists Confirm the cause with a scan before replacing parts.