P1340 Code: Camshaft Position Sensor Circuit Malfunction
🟠 Moderate severity · drivable
The engine may run rough or be hard to start, but most vehicles can be driven short distances to a shop.
What P1340 means
P1340 is a manufacturer-specific code, most commonly reported on Toyota and Lexus vehicles. It means the engine computer detected a problem in the camshaft position sensor circuit, so it isn't getting a reliable signal about where the camshafts are. Without that signal, the computer can't time fuel injection and ignition correctly, which can cause poor running or a no-start.
Symptoms
- Check engine light is on
- Engine is hard to start or cranks without starting
- Rough idle or hesitation while driving
- Worse fuel economy
Common causes
- most common: Faulty camshaft position sensor
- common: Damaged wiring or a loose connector in the sensor circuit
- common: Dirt, oil, or metal debris on the sensor or its mounting
- less common: Worn or stretched timing chain or belt
- rare: Faulty engine computer (ECM)
How to fix it
| Fix | DIY? | Typical cost |
|---|---|---|
| Inspect the sensor wiring and connector and repair any damage | Yes | $10–50 |
| Replace the camshaft position sensor | Yes | $60–150 |
| Have the timing components inspected and replaced if worn | Mechanic | $400–1000 |
Frequently asked questions
Can I drive with P1340?
You can usually drive short distances, but the engine may stall, idle rough, or be hard to start. If it stalls while driving or won't restart, get it checked before going far.
What does the camshaft position sensor do?
It tells the engine computer where the camshafts are so the computer can time fuel injection and ignition. A bad signal can make the engine run poorly or not start.
Why did P1340 come back after I replaced the sensor?
Often the wiring or connector is the real problem, or the replacement sensor is faulty. Check the circuit with a multimeter and make sure the timing chain or belt hasn't stretched or skipped.
Related codes
P0340
P0340 Code: Camshaft Position Sensor Circuit Malfunction
P0335P0335 Code: Crankshaft Position Sensor Circuit Malfunction
Updated 2026-08. This page is informational and not a substitute for professional diagnosis.