Camshaft Position Sensor A Circuit, Bank 1 or Single Sensor
The computer detected a problem in the camshaft position sensor A circuit, which supplies engine synchronization information. A missing or unusable signal can affect starting and continued operation. The code does not isolate the sensor as the failed part. Power, ground, wiring and the target must be checked against the engine-specific design rather than guessed from location. Bank 1 is the cylinder 1 side, or the single-sensor configuration where applicable.
Can I keep driving?
If the engine stalls, the light flashes, shaking is severe, or power loss makes traffic unsafe, pull over safely and arrange towing. With a steady light and normal operation, ask a shop for advice based on symptoms before further driving.
Flashing light, burning smell or smoke? Pull over safely. Danger to life: call 911.
What does this code mean for your car?
The same code can need different checks depending on the model and engine. Enter your vehicle details to find relevant sources and checks.
Symptoms
- No-start or difficult starting
- Stalling or stumbling
- Engine warning and reduced power
Possible causes
- 1Faulty camshaft position sensor A
- 2Wiring, connector, supply or ground fault
- 3Damaged target wheel or incorrect sensor gap
- 4Electrical interference or controller fault
These possibilities are not ranked by frequency and do not diagnose your vehicle.
Checks you can safely do yourself
Safe checks only: engine off and cold, car on level ground.
- Save the code and freeze-frame data if your scanner offers them, without clearing anything.
- Note recent timing work and whether the fault appeared only when hot; do not try to reproduce stalling.
When you need a shop
Arrange towing if the engine stalls or mechanical noise occurs. Have a shop check supply and ground, scope the camshaft sensor A signal and cam/crank synchronization, and inspect the target and timing as indicated.
How much does it cost?
A US repair estimate needs a diagnosis and a local shop quote.
No verified US repair quote is available for this fault. The price depends on diagnosis, vehicle, parts and local labor; request 2-3 itemized quotes.
Get 2-3 quotes
Investigate this code for my carFAQ
Can I keep driving with P0340?
If the engine stalls, the light flashes, shaking is severe, or power loss makes traffic unsafe, pull over safely and arrange towing. With a steady light and normal operation, ask a shop for advice based on symptoms before further driving.
What can cause P0340?
Possible causes include faulty camshaft position sensor A; wiring, connector, supply or ground fault; damaged target wheel or incorrect sensor gap; electrical interference or controller fault. These are diagnostic possibilities, not a confirmed diagnosis or a parts shopping list.
Does clearing the code fix the problem?
No. Clearing a code does not repair the problem or prove that no fault exists. It may erase useful evidence and reset readiness monitors. Save codes and freeze-frame data first; confirming a repair requires the vehicle-specific checks.
What if this code appears during a used-car inspection?
Arrange an independent professional pre-purchase inspection before committing. Request a complete scan, readiness status and diagnosis of the relevant system. Get written findings and a repair estimate; an unlit warning lamp does not replace inspection.
How much does a P0340 repair cost?
No verified US repair quote is available for this fault. The price depends on diagnosis, vehicle, parts and local labor; request 2-3 itemized quotes.