MotorBitP0340: Camshaft Position Sensor A Circuit Malfunction (Bank 1 or Single Sensor)
Cam sensor circuit fault. Start-up can take longer, or the engine may run in limp timing.
Educational OBD2 information. Confirm on your vehicle with a scan tool. MotorBit can read this code, freeze frame, and live data over an ELM327 adapter.
What P0340 means
Camshaft position signal is missing or implausible versus crank.
Why the check engine light comes on
Cam/crank correlation is required for sequential injection and variable valve timing.
Common causes
- Failed CMP sensor
- Timing chain jump
- Wiring
- Reluctor damage
Typical symptoms
- Long crank
- Rough running
- VVT-related rattles on some engines
What to do next
- Check related timing codes (P0011, P0016).
- Do not assume the sensor only — a jumped chain can set P0340.
How MotorBit helps
Open MotorBit, connect your ELM327, and read P0340 with freeze frame (RPM, load, temperature, speed at the moment the fault set). Then watch live PIDs and fuel trims instead of replacing parts by guesswork. When the repair is verified, clear the code and re-check monitors.
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FAQ
Is P0340 serious?
Severity is listed as high on this page. Misfire, crank/cam, and communication codes deserve faster attention than a tiny EVAP leak.
Will disconnecting the battery clear P0340?
It may hide the lamp temporarily, but the fault usually returns and you lose freeze-frame evidence. Scan first, then clear after the repair.
Can MotorBit clear P0340?
Yes, after you understand the cause. Clearing without a repair is how the light comes back on the next drive cycle.