What are the Symptoms and Causes of P0340 Code? | Ho to Fix P0340?

The camshaft position (CMP) sensor is a major part of your vehicle. It contains a complex network of electrical connectors and wiring to function. When your camshaft position sensor A circuit malfunctions, your powertrain control module (PCM) triggers the P0340 code. The P0340 code is a serious problem that demands immediate attention. This article mainly explains the symptoms, causes, and repair cost of the P0340 code.

P0340 Code Definition

P0340 code stands for “Camshaft Position Sensor “A” Circuit Malfunction.” 

What Does P0340 Code Mean?

The P0340 code indicates a problem with the Camshaft Position Sensor A circuit. This could be due to faulty camshaft position sensor wiring or a damaged camshaft position sensor. The P0340 doesn’t belong to the bad camshaft timing.

P0340 code

Precise camshaft position sensor readings are crucial for advanced internal combustion engines to achieve maximum efficiency. These readings play a big role in fuel injection timing and ignition timing. They can be affected by the accuracy of the data received.       

The signal from the engine’s camshaft position sensor is the main source of information for all engine speed-related statistics in many contemporary automobiles.

The main function of the camshaft position sensor is to calculate the rotational speed of the camshaft. During the rotation, the camshaft position sensor also records the exact position of the camshaft. This sensor sends the camshaft information to the PCM, and the PCM uses this information to adjust the ignition and fuel injection system timing.

The disturbed or improper signals from the camshaft to the PCM can result in misfires and sub-optimal fuel-to-air mixtures.

With the detection of these improper signals, the PCM triggers the DTC P0340 and illuminates the check engine light. This illuminated check engine light is here to warn the driver about the issue within the engine of his car.

Causes of the P0340 Code

The following list includes the most usual causes of the DTC P0340:

  • An issue with the camshaft position sensor
  • Damaged wire in the circuit for the camshaft position sensor
  • Engine misfiring
  • Crankshaft position sensor malfunction
  • Breakage in valve timing parts like damaged timing belt, old or damaged timing chain guides, or faulty timing sprockets
  • Crankshaft reluctor ring breakage
  • A clogged or soiled camshaft reluctor wheel
  • Damaged wiring of the camshaft position sensor
  • Outdated PCM software
  • Fault in PCM. The probability of having a bad PCM is very low, so it is recommended to carefully check the other issues before reprogramming and reinstalling the PCM.

Read More: P0336 Code Symptoms and Causes

Symptoms of Code P0340

The P0340 code generates one of the below-given symptoms:

  1. Check engine light illumination
  2. Vehicle engine misfire 
  3. Poor acceleration
  4. Difficult start
  5. Rough or erratic idle
  6. Engine vibration
  7. Intermittent stalling
  8. Poor fuel economy
  9. Erratic idle

Read More: P0014 Code Symptoms and Causes

How to diagnose the P0340 Code

You must have the following tools to diagnose the P0340 code:

  • Auto Repair Manual
  • Basic Hand Tools
  • Diagnostic OBD Scan Tool
  • Multimeter
  • Electrical Contact Cleaner

Follow the below-given steps to diagnose the P0340 trouble code:

  • Check for the trouble codes associated with this problem by connecting an OBD2 scanner. See if the code disappears by attempting to delete it.
  • If the code appeared, you would have a choice between two possibilities. The camshaft position sensor ‘A’ can be determined by calculating the precise ohm values or signal by using an oscilloscope. It might be difficult to measure the CMP sensor if you’ve never done it before.
  • It will be necessary to replace the camshaft position sensor if the voltage values differ from the actual ones. CMP sensor is affordable and simple to replace.
  • If the fault code reappears after you’ve fixed or replaced the sensor, you must measure and examine the wiring between the PCM and the sensor.
  • Detach the PCM and sensor from your car. Ensure no connections are made between the wires and the ground.
  • Look for cracks, rust, or a loose connection in the connector.
  • After all these steps, if your system still shows the P0340 code, then the problem is with the PCM of your car. Before spending a lot of money on a new PCM, you should be certain that it is the issue.

Common P0340 code Diagnosis Mistakes

  1. Examining the wiring and connections is essential before replacing the CMP sensor to rule them out as potential causes of the issue. This is the most frequent mistake while determining the cause of the P0340 code.
  2. Another error committed during the diagnostic process is failing to consider a CKP sensor issue or a misfiring issue as potential origins of the P0340.

Repair Cost of P0340 Trouble Code

The repair or fixing cost of the P0340 trouble code varies according to the vehicle model and the cause of the problem. The repair cost of the DTC P0340 is given below according to the repair of different parts:

  • Camshaft position sensor: $110 to $310 
  • Timing chain replacement: $190 to $1000 
  • PCM: $1100 to $1300 
  • Crankshaft position sensor: $190 to $270 

FAQ Section

How serious is the P0340 Code?

DTC P0340 is considered a serious diagnostic trouble code. The car may fail to start if it has a P0340 trouble code. The low power and unable to start a car, both events can be dangerous while driving. So, this code can be unsafe and hence can create unexpected and dangerous incidents.

Ignoring this trouble code for a long period of time can cause damage to several parts of the engine.

What does Nissan P0340 mean?

The DTC P034 shows the issue in the circuitry of the camshaft position sensor. The PCM receives information from this sensor on the rotational speed and the position of the camshaft. The PCM uses this information to match the timing of the ignition system with the fuel injection.

Does P0340 result in a no-start?

When an improper or broken signal has been sent to the PCM through the sensor, the PCM fails to adjust the ignition spark and the fuel injector timings, and thus the PCM triggers DTC P0340. As a result, the check engine light illuminates and results in a no-start condition.

Can My car run without a camshaft position sensor?

The car can’t run without a camshaft position sensor. The engine will either start or stall if it doesn’t turn over. The engine will run poorly if the same sensor is unplugged and no signal is sent.

What repairs can fix the P0340 code?

  • Camshaft position (CMP) sensor replacement.
  • The CMP sensor connection that is rusted or broken should be fixed or replaced.
  • Changing or repairing the wiring for the camshaft position sensor.
  • Crankshaft Position Sensor Replacement.
  • Service your car if misfire codes are detected before changing the camshaft position sensor.
  • PCM replacement or programming.

Can timing cause P0340?

A problem with the camshaft position sensor’s circuit is what leads to DTC P0340. Since this is just an electrical problem, it is obvious that incorrect camshaft timing is not the cause of the P0340.

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