The P0343 code is defined as: Camshaft position sensor circuit “A” circuit high input. This code is a generic fault, which means it applies to all vehicles manufactured since 2003.
It is most common among particular brands, such as Chevrolet, Ford, Hyundai, Kia, Toyota and Volkswagen vehicles. However, this code can appear on any other brand.
The specifications of this code may vary a little between brands, but broadly speaking it means the same thing.
Camshaft Sensor Operation
To record the engine’s own speed, there are several electronic devices located everywhere that take care of this. One of these devices is a camshaft sensor responsible for recording the position and speed of the camshaft.
The engine control module (ECM) uses this information to control ignition and fuel injection.
camshaft position sensor Monitors the camshaft for specific cylinder identification and determines piston position. The sensor system consists of a rotating part, usually a disk, and a static part, the actual sensor.
When the engine is running, the high and low parts of the gears cause the gap with the sensor to change. A change in space causes a change in the magnetic field. A change in the magnetic field causes a change in the sensor voltage.
The camshaft position sensor provides different control of engine parts. Synchronizing cylinder identification signals.
Fault code P0343 is one of several common fault codes related to the camshaft position sensor (CPS). It means that the sensor signal is too high, exceeding the allowed parameters established by the vehicle manufacturer.
P0343 refers to sensor “A” on bank 1. Bank 1 is the side of the engine that contains cylinder 1. Of course, if the engine is a single bank, this description is not necessary.
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What is Code P0343?
Error code P0343 refers to a voltage problem with the CMP or camshaft position sensor.
This sensor is a fixed electromagnetic sensor connected to the rotating part of the camshaft, which works by recording the position of the “teeth” to indicate the stroke of the pistons, giving the PCM the information to adjust the correct fuel and spark.
The position of the camshaft creates several gaps between the sensor, and this change in the magnetic field changes the sensor voltage.
Fault code P0343 It is set when the detected voltage is not within the parameters established by the manufacturer and is applied, as we already mentioned, to the Bank 1 sensor that monitors cylinder 1.
Common Symptoms of Code P0343
A faulty CMP sensor can cause the PCM to deliver an incorrect amount of fuel and spark, leading to several problematic driving conditions, such as inconsistent starting problems and stalling.
Other common symptoms of error code P0343 are:
- Engine with irregular idle.
- In some cases, the engine may shut down for no apparent reason.
- Difficult start.
- Engine stalling.
- Power loss.
- Check Engine light is activated.
- Higher fuel consumption.
The vehicle is likely to be kept in operation with fault code P0343 activated. But it may be difficult to start and there may be a drop in power and unstable engine operation.
To avoid damage to other engine components when this code is detected, it is advisable to correct the fault as soon as possible. Additionally, you are running the risk of being stranded, since when it shuts off, it will be difficult to start the vehicle again.
Possible Causes of Code P0343
There are many reasons for a vehicle to register this code. Let’s look at the most common ones.
- Ground circuit to CMP sensor open or shorted.
- Short to 5V in the signal circuit to the CMP sensor.
- The signal circuit between the CMP sensor and the PCM is open or shorted.
- Damaged CMP sensor.
- Defective power wiring.
- Use of defective or contaminated oil.
- Defective PCM, although this is not common.
How to Diagnose Code P0343
Below are the steps necessary to correctly diagnose this fault.
1. Connect the scanner
The first thing you should do is connect the OBD 2 scanner to check if you actually have it activated. the code P0343 and what other codes are combined.
Take note of all the codes that appear on the scanner screen.
2. Take a test drive
Then you must check whether or not there is intermittency in the fault. To do this you must erase all the codes and take a test drive, if the car allows it.
In some cases you will not be able to do this step because the car does not start, the code appearing automatically. If so, continue to the next step.
If the code does not appear, you had an intermittent problem and it can only be repaired when it worsens. If the code appears again, you should start with a visual check of the sensor and all system wiring.
3. Wiring check
Verify that the wiring of the entire control system of this sensor is in good condition. Look for burns, breaks, and disconnections. Proceed to repair in case you find any fault.
This check should include checking the fuses. Typically, the fuses for this system are located in the main fuselage. Be guided by your car manual to identify the fuses.
If you find damaged fuses, you must replace them with exactly the same ones, respecting their number and color.
Clear the codes with the scanner again and take the test drive again.
4. Check the power supply
If the error code appears again, check the battery charge and inspect the starter motor. Resolve the problem, then clear the error codes from the PCM memory again and recheck the system to see if error P0343 appears again.
This procedure must be performed every time repairs have been made. This will help determine if the issue has been resolved.
5. Sensor check
You must determine whether or not the sensor is damaged due to an oil leak, damaged wiring, or frayed wiring.
Please note that these sensors can be cleaned to return them to normal. An electrical contact cleaner or even alcohol is usually used to clean these components.
Clean the sensor and check its condition, so that it is not hit or with a damaged connection. Clear the codes again and try to start the car.
If the code returns, the problem is most likely with the sensor itself. To be sure of this, you can use a multimeter and a test light to check if the sensor is receiving the voltage supply it needs to function properly.
If you don’t get the voltage you need, you should replace the sensor with a high-quality replacement part. You should find the reference voltages in your car’s service manual.
Then, once the sensor change is complete, the codes are cleared and the vehicle will be taken for a test drive to ensure that the new sensor works correctly and that the code does not return.
Check the camshaft sensor itself, if it needs to be replaced. In most cases, these steps will help resolve the issue with your vehicle.
How to Fix Code P0343
Some suggested steps to troubleshoot and fix error code P0343:
- Inspect the wiring for corrosion, poor connections, or worn insulation.
- Check the status of the CMP sensor. Look for corrosion and defects in the connector. Apply dielectric grease to the connection.
- Replace the camshaft position sensor.
- Test the battery status. A low battery can cause a code related to the electrical system to set.
- Check the starter motor for excessive pull, which indicates weak recoil.
Often, replacing the sensor will fix the P0343 error code, but not necessarily. Therefore, it is important to verify all elements.
Some of the most common fixes for this code include:
- Replacing the CMP sensor.
- Replacement of damaged connectors or wiring.
- Nearby oil leak repair.
- Cleaning the ground cables.
- Sensor cleaning.
Common Errors When Diagnosing Code P0343
Most of the time, this failure is treated directly as a problem with the camshaft and crankshaft sensors, and they are replaced without prior inspection.
However, it is important to realize that the wiring harness or a simple damaged connection may be the reason for the problem. error code P0343. Therefore, it is necessary to carry out a step-by-step diagnosis where all the components of this system are reviewed.
This, is before deciding to change any part.
How Serious Is a P0343 Code?
If your engine is still running with this check engine light on and the P0343 code, it is best to get it repaired as soon as possible. There’s a good chance that the engine will decide to stop running when the sensor fails completely, and that could leave you stranded.
Between the time the check engine light comes on and the engine stops running, the starter motor and battery can end up receiving additional wear and tear from prolonged engine cranking.
Since this is an easy repair to make, it is best to do it as soon as possible.
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CMP sensors are crucial for fuel injection in modern vehicles. Error code P0343 must be addressed quickly as it affects the driving quality of the vehicle
Additionally, this error usually involves faulty replacement sensors. It is imperative that high-quality replacements are used to avoid the hassle and inconvenience of the problem.
If you want to know other articles similar to Code P0343. For Camshaft Position Sensor Circuit “A” High Input you can visit the category Fault Codes.