Trouble code
P0340
Camshaft Position Sensor A Circuit Malfunction
What P0340 means
The camshaft position signal is missing or implausible. The computer needs it to know which cylinder is on its firing stroke.
Symptoms you may notice
- Hard starting
- Stalling
- Rough running
- Sometimes no start at all
Common causes, cheapest first
- Failed camshaft position sensor
- Wiring or connector fault
- Timing belt or chain jumped
- Damaged tone ring
Before you buy anythingIf this appears alongside a crankshaft correlation code, suspect a jumped timing belt or chain before buying sensors. That is a much more serious problem and replacing sensors will not touch it.
What to do next
- Confirm the code with your own scan tool, or have it read free at a chain parts store.
- Decode your VIN so you know your exact engine and build date.
- Work down the causes above from cheapest to most expensive.
- Search NHTSA for a recall or service bulletin covering this symptom on your vehicle.
- Read the ignition buying guide before ordering.
P0340 is a generic OBD-II code, standardized across every make and model sold in the US from 1996 onward. The meaning is the same on any vehicle; the specific part and its location are not.
Parts
Parts commonly needed for P0340
These go to Amazon. We earn a commission if you buy, at no extra cost to you — see our affiliate disclosure. Which one you actually need depends on diagnosis — read the note above first.
Confirm fitment against your VIN on the listing page before ordering. A part that matches your year and model can still be wrong for your build date or engine code.