P0340 Code: Symptoms, Causes (& Repair Cost 2022)

The camshaft position sensor is one of the most important parts of the car. This sensor requires a complex network of electrical connectors and wiring to function. When your camshaft position sensor A circuit goes bad, your powertrain control module (PCM) triggers the P0340 code. A P0340 error code can be a serious issue that requires immediate attention. This article mainly explains the P0340 code symptoms and causes.

P0340 Code Definition

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

What Does P0340 Code Mean?

The P0340 error code indicates a problem with the Camshaft Position Sensor A circuit. It is possible that the wires leading to the camshaft position sensor are damaged, or that the sensor itself has failed. This error code isn’t a sign of bad camshaft timing.

P0340 Code

The latest IC engines rely upon accurate data regarding engine timing, in order to optimize various operational functions. The most vital of these functions relates to ignition and fuel injection timing, which can both suffer indefinitely, should inaccurate engine speed signals be relayed to the corresponding PCM.

Many modern vehicles rely upon the signal from their engine’s camshaft position sensor as the primary source of all engine speed related data. 

The camshaft position sensor calculates the speed at which the engine’s camshaft rotates. It also keeps track of the shaft’s precise position during rotation. It signals the PCM, which uses the sensor data to set the timing for the ignition and fuel injection systems.

Disrupting the signal from the camshaft position sensor throws off the engine’s precise timing and can cause performance problems, such as misfires and sub-optimal fuel-to-air mixtures. The PCM will trigger the DTC P0340 and activate the Check Engine Light to warn the driver that something went wrong.

Causes of the P0340 Code

The most common causes of the P0340 code are given below:

  • A faulty camshaft position sensor
  • Damaged wiring within camshaft position sensor circuit
  • A faulty crankshaft position sensor
  • Damaged or worn valve timing components such as worn timing belts, worn or damaged timing chain guides, or worn timing sprockets
  • Dirty or obstructed camshaft reluctor wheel
  • Damaged camshaft position sensor wiring
  • PCM software update needed 
  • Bad or faulty PCM, but note that since this is a rare event, the fault must be sought elsewhere before any control module is reprogrammed or replaced

Read More: P0420 Causes and Symptoms

Symptoms of Code P0340

The following are several of the most common symptoms of DTC P0340:

  • Illuminated check engine light
  • Loss of power while driving
  • The engine may start, but shuts off again almost immediately
  • Rough or erratic idle
  • Intermittent stalling
  • Fuel consumption may increase noticeably
  • Vehicle engine misfire 

Read More: P0457 Symptoms and Causes

How to diagnose the P0340 Code? 

  • Connect an OBD2 scanner and look for any trouble codes related to this issue. Try deleting the code and see if it reappears. 
  • If the code comes up, you’d have a choice between two options. If you’ve never measured the camshaft position sensor before, it can be a challenge. Camshaft position sensor ‘A’ can either be measured by finding the correct ohm values or by checking the signal with an oscilloscope. 
  • If the voltage readings are abnormal, the camshaft position sensor will need to be replaced.
  • Sensors for camshafts are inexpensive and simple to replace
  • You must measure and inspect the wiring between the powertrain control module and the sensor if the trouble code returns after you have repaired or replaced the sensor.  
  • Remove the sensor and the PCM from the vehicle. Make sure there aren’t any connections to the ground or between the wires. 
  •  If the wiring appears to be in order, the only other possibility is that the powertrain control module has gone bad. You should make sure that the engine control unit is the problem before you spend a lot of money on a new one.

Common mistakes when diagnosing the P0340 Code

  1. Before replacing the camshaft position sensor, it is important to inspect the wiring and connectors to rule them out as the cause of the problem. This is the most common mistake when diagnosing the P0340 trouble code.
  2. Another mistake that is made during the diagnostic procedure is neglecting to consider a misfiring problem or a crankshaft sensor problem as possible sources of the P0340 trouble code.

What repairs can fix the P0340 Code? 

  • Replacing crankshaft position sensor 
  • Repairing or replacing the camshaft position sensor circuit connector 
  • Repairing or replacing the camshaft position sensor circuit wiring 
  • Replacing the camshaft position sensor 
  • If misfire codes are present, perform a tune-up of the vehicle before replacing the camshaft position sensor 
  • Replacing or reprogramming the PCM 

Repair Cost of P0340 Code

The repair or fixing cost of the P0340 code depends on 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:

Crankshaft position sensor$180 to $260 
Camshaft position sensor$110 to $310 
PCM replacement$990 to $1210 
Timing chain or belt replacement$190 to $1000 

FAQ Section

What does P0340 mean?

The OBD-II diagnostic trouble code P0340 indicates a “Camshaft Position Sensor “A” Circuit Malfunction.” It covers the entire circuit attached to the aforementioned sensor, such as the electric wiring and the powertrain control module (PCM).

How serious is the P0340 Code?

P0340 code is a serious diagnostic trouble code. A problem with the car’s ignition could cause it to fail to start. The driver may also feel a lack of power while driving. The driver and anyone else on the road are in danger because of these symptoms, which make the vehicle unsafe to operate.

If you ignore the P0340 error code for too long, you run the risk of causing damage to other engine components. Diagnosing and fixing the P0340 error code as soon as possible is critical. 

What is the P0340 code of Nissan?

The code P0340 signals that there is a problem with the circuit of the camshaft position sensor. This sensor determines the rotational speed and the camshaft position, and then it sends this information to the PCM. With this information, the PCM synchronizes the timing of the fuel injection with the timing of the ignition system (the spark).

Will P0340 cause a no start?

When the signal to and from the camshaft position sensor and the PCM is broken, the ignition spark and fuel injector timing will fail and the PCM will store the P0340 OBD-II trouble code. This will trigger the illumination of the Check Engine Light and most likely be the source of your no starting issue.

Can timing cause P0340 code?

This trouble code clearly states that there is an electrical problem in the circuit to the camshaft position sensor. Therefore, the P0340 trouble code is not caused by faulty camshaft timing.

Can you drive with P0340 Code?

You can technically drive your car with the P0340 code, but it’s highly recommended that you don’t. The P0340 code is directly related to the drivetrain and indicates that there’s a problem with the camshaft position sensor which is one of the most important parts of a car’s engine.

Can a 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 makes a camshaft sensor go bad?

There are many reasons why the camshaft position sensor could fail. Some of these include wear-and-tear, water damage, and oil embedded in the engine. There are also sensors that fail due to corrosion, which is a common problem for camshaft position sensor circuits.

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