P0343 OBD-II Trouble Code: Camshaft Position Sensor Circuit High Input

check engine light

P0343 trouble code definition

A P0343 trouble code is related to a vehicle’s timing system and the camshaft position sensor that monitors the rotation of the camshaft to relay data to the engine computer so it can calculate the appropriate amount of fuel and ignition.

What the P0343 code means

P0343 is an OBD-II generic code for a voltage problem with the camshaft position sensor. This is a fixed electromagnetic sensor that’s connected to a rotating part on the camshaft that records the position of the “teeth” to indicate the stroke of each piston so the computer can apply the appropriate fuel and spark. The position of the camshaft creates various gaps between the sensor which change the magnetic field to change the voltage from the sensor. When a P0343 is present, that voltage is not within the manufacturer’s parameters. It also applies to the bank 1 sensor that monitors cylinder 1.

What causes the P0343 code?

Usually, the camshaft position sensor has been fouled from oil or moisture, causing a bad ground or voltage in the signal wiring. However, other likely causes include:

  • Faulty camshaft position sensor
  • Faulty ground wiring
  • Faulty power wiring
  • Faulty starter motor
  • Weak or dead battery
  • Faulty engine computer

What are the symptoms of the P0343 code?

Because a faulty camshaft position sensor can cause the engine computer to supply the incorrect amount of fuel and or spark, it’s likely that you’ll encounter poor driving conditions with a P0343. It’s typical for the code to result in bucking, surging, stalling or inconsistent starting issues.

How does a mechanic diagnose the P0343 code?

Your mechanic will start with a visual inspection of the sensor to determine if it’s being fouled from an oil leak or frayed/damaged wiring. It is possible to clean a sensor enough for it to work as it should. Electrical contact cleaner or rubbing alcohol can help in cleaning and your mechanic will likely clear the code to see if it returns. If it does, the sensor itself is likely the culprit. This can be tested with a multimeter and a test light to determine if it’s getting the voltage supply it needs. If not, your mechanic will likely replace the sensor with a high-quality replacement part, clear the code and test drive to ensure the new sensor works.

Common mistakes when diagnosing the P0343 code

The most common mistake when dealing with a P0343 circles around bad replacement sensors. It’s important to use high-quality replacement parts and avoid cheaper or used variants. Because some sensors will also be fouled due to oil leaks, it’s recommended to have any near-by leaks repaired so the problem doesn’t persist.

How serious is the P0343 code?

Because the camshaft position sensor is so critical for a modern vehicle’s fuel injection, a P0343 can severely affect the way a vehicle drives. It’s wise to address this code as quickly as you can.

What repairs can fix the P0343 code?

The most common repairs for a P0343 are as follows:

Additional comments for consideration regarding the P0343 code

P0343 codes seem to be prominent with Chevrolet, Kia, Volkswagen and Hyundai models - typically around the model years 2003 to 2005. It’s also not too uncommon for a P0343 code to trigger additional trouble codes as a result.

Need help with a P0343 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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