Replaced Camshaft Position Sensor but Still Get Code (Fixed)

Replaced camshaft position sensor but still get code is usually due to problems with the sensor itself and sometimes due to wiring or circuit issues. Getting the P0340 error code after replacing a faulty camshaft position sensor can be worrying.

It could cause poor fuel economy, poor drivability or predispose your engine to possible damage. This article contains detailed information on this issue and how you can easily fix it in no time.

What Causes the P0340 Error Code After Replacing the Camshaft Sensor?

What causes the P0340 error code after replacing the camshaft sensor is a bad camshaft position. Another possible cause is a fault in the wiring coming from and going to the sensor. However, there are many other potential causes that you should pay attention to.

• Faulty Camshaft Position Sensor

This is the number one culprit when you get a P0340 code with newly replaced camshaft sensors. The sensors collaborate to furnish precise timing information to the ECU. Therefore, if one sensor malfunctions, it can disrupt the functioning of the other and give rise to complications.

In such instances, replacing the sensor becomes necessary. Local auto parts stores or online platforms offer options for purchasing a new sensor.

• Issues With the Camshaft Wiring

It is important to note that the root cause of the problem might not lie within the camshaft position sensor itself but rather in the wiring connected to it. The operation of the camshaft position sensor relies on electrical power. When issues arise with the electrical connector or wiring associated with the sensor, it can trigger the P0340 code. These issues may include a break or short circuit in the wiring, loose connections or faulty grounding.

• Bad Camshaft Sensor Reluctor Wheel

The reluctor wheel is a notched wheel that is affixed to the camshaft. Its role is to pass by the sensor’s teeth, disrupting the magnetic field. This disruption generates an electric signal used by the ECM and PCM. Should the reluctor wheel sustain damage, it can activate the P0340 code.

• Defective ECU

The position sensor code may also persist if the Engine Control Unit is malfunctioning. In that case, the ECU cannot effectively control the engine’s timing due to the inability of the sensor to provide accurate signals. As a result, your car may have issues like engine misfires or other related problems.

• Defective Starter Motor

The starter motor, a compact electric motor responsible for initiating engine startup, can occasionally be the culprit behind the triggering of the P0340 code. It occurs when the engine fails to rotate rapidly enough. This impedes the camshaft position sensor from supplying precise data to the ECU.

• Timing Chain Problems

When the timing chain undergoes stretching or becomes slack, it can hinder the camshaft position sensor from supplying precise information to the ECU. As a result, error codes such as P0340 may be generated.

Timing chain issues can disrupt the synchronization between the camshaft and the crankshaft, resulting in inconsistent readings from the camshaft position sensor. This discrepancy in timing information can trigger the P0340 error code.

• Insufficient Oil Pressure or Clogged Oil Passage

Insufficient lubrication in the engine can impede the accurate detection of the camshaft’s position by the camshaft position sensor, leading to the generation of error codes.

Additionally, if the oil passages that supply oil to the camshaft position sensor become obstructed, it can further compromise the sensor’s functionality. This can lead to the generation of the trouble code.

• Faulty VVT System

The occurrence of error codes after replacing camshaft sensor can be attributed to a malfunction Variable Valve Timing (VVT) system in your engine. The VVT system plays a vital role in adjusting the engine’s timing per different driving conditions. When the VVT system fails to operate correctly, it can give rise to engine misfires or other related complications.

• Malfunctioning Fuel Injectors

The generation of error codes can also be due to defective fuel injectors, which can disrupt the engine’s timing and lead to misfires or other complications. Furthermore, when fuel injectors malfunction, they may impact the accurate signal detection of the camshaft position sensor. It could trigger the activation of the P0340 error code.

• Inadequate Camshaft Timing

In cases where the camshaft timing is not aligned correctly, the camshaft position sensor becomes incapable of supplying precise data to the ECU. This can result in the generation of error codes even after replacing the sensor. Improper camshaft timing will also disrupt how the camshaft and the crankshaft are synced. As a result, it causes inconsistent signals from the camshaft position sensor.

How Can You Fix the Camshaft Position Sensor Error Code?

You can fix the camshaft position sensor error code by first diagnosing the underlying issue to detect what might trigger the problem. Then you can fix the issue and reset the P0340 code afterward. There are many remedies to the problem since different sources can be identified.

As stated earlier, the error code P0340 may persist due to various reasons, including defective ECM, wiring problems and even issues with the sensors. Therefore, estimating the cost of fixing the error code may only be possible with a proper diagnosis.

Auto mechanics may charge between 75 to 150 dollars for the diagnosis. However, the good news is that you can diagnose the problem yourself with the right equipment. Let’s examine the possible fixes you can use to eliminate the error code after replacing your car’s camshaft sensor.

• Relearn or Recalibrate the Camshaft Position Sensor

After replacing the sensor, it is essential to relearn it to prevent the car’s ECU from retaining data from the previous sensor, which could trigger an error code. To retrain the camshaft position sensor,

follow the steps outlined below:

• Step 1: Start the car and connect an OBDII scanning tool. Turn on the scanning tool and select your vehicle’s brand and model. Alternatively, choose the “Auto Detect” option, and the tool will automatically read your system.
• Step 2: Navigate to the diagnosis section and select the Control Unit > Powertrain > ECM option.
• Step 3: Choose the “Cam crank to relearn” option, then select the “Special Functions” option. A new window will appear, providing information about the retraining status. Simply choose “OK” on this window.
• Step 4: Start the engine and allow it to run. Wait until the engine coolant reaches the desired temperature or gradually increase your car’s speed until the desired temperature is reached. The relearning process will then take place automatically.

 

• Check Your Car’s Camshaft Sensor Wiring

If the relearn process fails to resolve the error, there may be an issue with the wiring responsible for transmitting signals to the ECU. To examine the wiring in detail, follow the steps below:

• Examine the wiring diagram: Each vehicle has different wiring diagrams, so check the specific one for your car. Typically, the camshaft sensor has three wires, each with different colors that may vary. Identify the sensor signal, power supply and sensor ground wires.
• Check for short circuits: Inspect the connection lines for any short circuits using an ohmmeter. Disconnect the control unit plug and use the ohmmeter to measure the connection lines from the sensor plug to the vehicle ground.
• Verify the power supply: Using a multimeter, check the voltage by setting the multimeter to PIN 1. Ensure that the power source of the circuit is approximately 5 amperes.
• Test the sensor ground and signal circuits: Confirm continuity between the sensor wire harness and the ECM wiring harness for the ground circuit. Similarly, check for continuity between the cam sensor and the ECM harness for the position sensor circuit. Replace any damaged wires as necessary.
• Verify the supply voltage: Connect the measuring cable to an oscilloscope and start the engine to check the signal voltage. The oscilloscope should ideally display a square wave signal, indicating proper functionality.

 

• Examine and Fix the O-Rings

Two O-rings are needed to ensure the proper functioning of the camshaft position sensor. The primary component of the camshaft position sensor comes equipped with one O-ring. The car manufacturer is responsible for providing the second O-ring.

Please note that the included O-ring with the primary component may appear as a plastic ridge, so you may mistakenly attempt to reuse the old O-ring. However, this affects correct installation and creates a gap that can cause issues. To address this, you must remove the old O-ring before installing the new one. Additionally, it is essential to clean the O-ring thoroughly before utilizing it.

• Align the Reluctor Wheel Correctly

If the previously mentioned steps do not resolve the issue, you should inspect the Reluctor wheel. One common oversight is not correctly aligning the camshaft position sensor with the reluctor wheel after replacement. To address this, ensure that the teeth of the Reluctor wheel are accurately aligned with the camshaft position sensor.

In most vehicles, the sensor should align with the 20th tooth of the Reluctor wheel. Additionally, thoroughly examine the Reluctor wheel to determine if its teeth are damaged or compromised.

• Replace the Timing Chain

Professional mechanics have differing opinions regarding the role of the timing chain in relation to the specific error code. However, it is important to thoroughly inspect the timing chain if the error codes persist despite examining the reluctor wheel component.

If the timing chain is the underlying cause of the issue, it will require replacement. Replacing a timing chain can cost between 200 and 1,000 dollars, depending on the vehicle type.

FAQs

– What Should You Do Before and After You Replace Your Camshaft Sensor?

What you should do before and after you replace your camshaft sensor include checking your car’s engine oil level and quality. Low oil level or dirty oil may cause the camshaft sensor to fail. You should also examine the wiring and connector for damages and misalignment.

Ensure you clear the error code after replacing the sensor. Then you can also take your car for a test drive to be sure the code does not return.

• Will Your Car Run With a Faulty Camshaft Position Sensor?

Yes, your can will run with a faulty camshaft position sensor. However, the car will continue to show various functionality issues that tend to worsen over time. These issues include a no-start problem, ignition issues, poor acceleration, etc. If left unchecked, they may ultimately damage the car engine.

Conclusion

If you have read this far, you should already know why the P0340 error code persists after you’ve changed camshaft position sensor and car won’t start.

Here are some of the things we covered in the article:

• The most common cause of a persisting P0340 error code, even after replacing the camshaft sensor, is a faulty camshaft position sensor.
• Another possible cause of this issue is a fault in the wiring coming from and going to the sensor.
• Other causes include a faulty ECU, a problem with the reluctor wheel, an O-rings issue, a bad crankshaft, problems with the engine timing belt, check engine light, etc.
• You can get rid of the code by relearning or recalibrating the sensor or fixing any wiring problems you have found.
• Alternatively, you can address other issues relating to the crankshaft position sensor, check engine light, O-rings, timing chain, etc.

By inspecting the sensor’s wiring and other vehicle components, you can identify and fix the underlying issues accordingly. We hope the information we provided will help you understand the issue better and address it appropriately.