Skip the auto shop - Our mechanics make house calls

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

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.


Post a question and get free advice from our certified mechanics.


More related articles

How to Renew Your Car Registration in Oklahoma(DELETED)
Having your car registered with the Oklahoma Tax Commission is an important part of driving legally in this state. You will need to do this within 30 days of moving to Oklahoma...
Insurance Requirements for Car Registration in Kentucky
The Kentucky Transportation Cabinet requires that all drivers in Kentucky carry liability automotive insurance, or “financial responsibility” in order to operate a vehicle legally and maintain vehicle...
How to Transfer a Car Title in Idaho
In order to prove ownership of a car, you must have the title. However, when a car is sold, given away or inherited, the title needs...

Related questions

Q: Engine not firing

Hello, thanks for writing in about your Ford F-150. You will need to scan the computer to see if there is codes for the crankshaft or camshaft sensor. If you'd like to have this fixed, consider YourMechanic, as a certified...

Q: My vehicle is shaking when I drive past 50 mph

Hi there. From the description you have given, the drivability problem your vehicle has may be a fuel delivery problem. This would account for your vehicle not wanting to start that one day. Next day, you were entering the highway...

Q: Powertrain warning lamp

In this case you will need to have the computer scanned to retrieve the codes that are stored. The codes will indicate the exact problem areas. Have the trouble codes and warning light diagnosed by a certified technician, such as...