P0340 – Meaning, Causes, Symptoms, & Fixes
Code P0340 Definition
Camshaft Position Sensor Circuit Malfunction
What Does P0340 Mean?
The camshaft position sensor located in the internal combustion engine monitors the position and rotational speed of the camshaft. It works hand in hand with the reluctor ring that creates a square wave voltage signal that the ECM interprets as the crankshaft position. The ECM uses this information to control ignition spark and fuel injector timing. When the trouble code P0340 is set, the ignition spark and fuel injector timing fails due to the engine not knowing when to fire these components.
What Are The Symptoms Of Code P0340?
- Check Engine Light
- The vehicle will not start – may be difficult to start
- Rough idle/stall
- Vehicle engine misfire
- Loss of power when driving
*In many cases there may be no noticeable issues with your vehicle
What Is The Cause Of P0340?
- A defective camshaft position sensor
- Damaged or dirty reluctor ring on the camshaft
- Defective, corroded, shorted camshaft position sensor circuit wiring
- Defective, corroded, shorted camshaft position sensor circuit connector
- A faulty crankshaft position sensor
- Stretched or misaligned timing components
- ECM software update needed
- Faulty ECM
How Serious Is Code P0340? – Severe
The vehicle may be difficult to start and the driver may also experience a lack of power when driving. It is possible for more damage to occur inside the engine of the vehicle if disregarded for an extended time period. It is extremely important to repair code P0340 as soon as possible.
Code P0340 Common Diagnosis Mistakes
Replacing the camshaft position sensor without checking the wiring, connector, or reluctor ring beforehand. There may also be the possibility of neglecting a misfire or timing error.
Tools Needed to Diagnose Code P0340:
How To Diagnose And Repair Code P0340:
Difficulty of Diagnosis and Repair – 3 out of 5
- Visually inspect the camshaft position sensor wiring in search of corroded, broken, or frayed wiring.
- Visually inspect the camshaft position sensor connector in search of corroded or broken connectors.
- Make any other repairs (if other codes are present) to make sure that other codes are not sources of the trouble code P0340.
- Check your camshaft position sensor’s voltage, ground, and signal readings with a multimeter. Check out this video for a visual reference on how to check it using your multimeter.
- If you find that the camshaft position sensor fails to produce a voltage or a signal, remove it and check the reluctor ring for damage, debris, or misalignment. If the reluctor ring appears in good condition, replace the camshaft position sensor.
- If the concern persists, perform the same test as you did on the camshaft position sensor to the crankshaft position sensor and its circuits. If it fails the tests, replace it.
- If the concern still persists, perform a continuity test on the camshaft and crankshaft position sensor circuits between the respective sensors and the ECM. Repair any faults you discover.
- If these steps do not resolve your Check Engine Light, you may need to visit a mechanic because there may be internal issues with the ECM, stretched or damaged timing components or the possibility of an ECM software update that may resolve the concern.
Estimated Cost of Repair
For error code P0340, one or more of the below repairs may be needed to solve the underlying issue. For each possible repair, the estimated cost of repair includes the cost of the relevant parts and the cost of labor required to make the repair.
- Camshaft position sensor $120-$300
- Crankshaft position sensor $190-$250
- ECM $1000-$1200
- Timing chain or belt replacement $200-$1000