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Common codes
P0420P0300P0171P0455P0442P0128P0401P0113

P0340: Camshaft position sensor circuit malfunction (Bank 1)

Drive carefully. Get it checked within a week or two.

Can I drive with P0340?

Yes, but drive carefully and get it checked soon. The engine cannot synchronize valve timing, causing extended cranking and reduced performance.

What does P0340 mean?

P0340 stands for Camshaft Position Sensor 'A' Circuit Malfunction (Bank 1 or Single Sensor).

Symptoms you may notice

  • Extended engine cranking (5 to 10 seconds) before starting
  • Sudden engine stalling while idling or slowing down
  • Noticeable lack of engine power and sluggish throttle

How much does it cost to fix?

Repair costs for code P0340 depend on the specific underlying root cause, ranging from simple DIY checks to component replacement. The table below lists the most common causes and rough price ranges in USD:

  • Faulty camshaft position (CMP) sensor
    $50-$160 common
  • Damaged or oil-fouled wiring connector
    $30-$80 possible
  • Stretched timing chain or jumped timing belt
    $600-$1800 possible
  • Weak vehicle battery during startup
    $100-$220 rare

What to do next

  1. Inspect the CMP sensor connector on the valve cover for engine oil leaks.
  2. Check timing belt/chain condition if engine rattles on cold start.
  3. Replace the camshaft position sensor.
Last updated: October 2026

Related codes

P0341 P0335 P0016 P0300
General guidance only, not a professional diagnosis. If the check-engine light is flashing, or the car is running rough, overheating or losing power, stop driving and get help.

About this code

Code P0340 indicates the engine computer is not receiving a reliable signal from the intake camshaft position sensor on Bank 1. Most modern vehicles can still start after prolonged cranking using the crankshaft sensor as a backup, but the engine runs in batch-fire fuel injection mode. Get it checked promptly to ensure a stretched timing chain is not the root cause.