P0340 Code Meaning, Causes, Symptoms, And How To Fix

The camshaft position sensor is a major part of your vehicle. It contains a complex network of electrical connectors and wiring to function. When there is something goes bad with the camshaft position sensor, 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 P0340 code meaning, symptoms, causes, and repair cost.

P0340 Code Definition

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

What Does the P0340 Code Mean?

The P0340 code indicates an issue 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.

When the communication signal between the camshaft position sensor and the PCM is disturbed, your 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

Your vehicle triggers the engine code P0340 due to one or more of the following causes:

  • A bad camshaft position sensor
  • Damaged wire in the circuit for the camshaft position sensor
  • Engine misfiring
  • A bad crankshaft position sensor
  • Breakage in valve timing parts like damaged timing belt, or faulty timing sprockets
  • Crankshaft reluctor ring breakage
  • A clogged or soiled camshaft reluctor wheel
  • Damaged wiring of the camshaft position sensor
  • Misaligned timing components
  • Outdated PCM software
  • An issue with the 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 starting conditions
  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 the trouble code P0340 by connecting an OBD2 scanner.
  • Inspect the cam sensor wiring and wiring harness to check the continuity of the camshaft sensor circuitry.
  • Use an oscilloscope or multimeter to check the voltage of the camshaft position sensor. 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.
  • If the fault code reappears after replacing the sensor, you must measure and examine the connections between the PCM and the sensor. Look for cracks, rust, or a loose connection in the connector.
  • After all these steps, if your system still shows the P0340 code, it is possible that 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. Replacing the camshaft position sensor without inspecting the wires and connections
  2. Replacing the unnecessary parts
  3. Replacing the camshaft position sensor without testing
  4. Using low-quality or aftermarket sensors
  5. Neglecting software updates

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

What repairs can fix the P0340 Code?

You need to repair or replace one or more of the following parts to fix the P0340 code:

  • Addressing related codes
  • Replace the bad camshaft position sensor
  • Repair the rusted or broken connections
  • Repair the damaged wires
  • Replace the bad crankshaft position sensor
  • Replace the damaged timing belt
  • Replace the bad reluctor ring
  • PCM replacement or programming

How serious is the P0340 Code?

The engine code P0340 is considered a serious trouble code. The car may fail to start if it has a P0340 trouble code. It may lead to hard starting conditions. It may also cause low engine power.

Driving with this code is 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.

FAQ Section

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.

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.

Read More
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