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Summary
  • The diagnostic trouble code (DTC) P0349 indicates “Camshaft Position Sensor ‘A’ Circuit Intermittent Bank 2.”
  • Your vehicle’s powertrain control module (PCM) will log this code when the crankshaft position sensor stops sending data.
  • Common causes of the P0349 code are camshaft position sensor failure, damaged tone ring, PCM failure, and issues in the circuits to the camshaft position sensor.
  • The symptoms of a P0349 code include decreased engine performance, the engine being unable to start, increased fuel consumption, and intermittent bucking or surging.

The camshaft position sensor is responsible for sending signals that inform the powertrain control module (PCM) of the cylinder position. This helps the PCM to control the fuel injectors and ignition coils. If the crankshaft position sensor fails to send data to the PCM, on-board diagnostics will log a P0349 code.

How a Camshaft Position Sensor Works

The camshaft position sensor (CMP) is a part of the spline phaser system operation that helps initiate a vehicle’s fuel-injection sequence. Inductive type CMP sensors create an AC voltage signal using a reluctor with teeth that increases and decreases the magnetic field, depending on the distance of each tooth from the sensor.

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As the sensor counts the number of teeth on the crankshaft that have passed, data is sent to the PCM to determine the position of the crankshaft on its full rotation. The rate of positional change is then used to measure the engine’s rotational speed.

By monitoring the changing magnetic resistance from the timing rotor, the crankshaft position sensor is able to send data to the PCM, helping the computer to calculate the camshaft angle and identify which cylinder is firing.

sensor trace of a 2006 Ford Escape with inductive sensors
This sensor trace is a 2006 Ford Escape 3.0L with inductive sensors. Red is the crank signal, green is the cam signal, and tan is coil current ramping. We can tell this trace was taken at idle because of the multi-strike firing of the coil. | Image Source: Richard McCuistian.
scope trace of the hall effect cam and crank sensors from a 2003 Honda CRV
This is the scope trace of the Hall Effect cam and crank sensors from a 2003 Honda CRV. The blue trace is the cam sensor and the red trace is the crank sensor. | Image Source: Richard McCuistian.

For more information that can help you address the P0349 code, read our technical discussion about the camshaft position sensor.

What Does a P0349 Code Mean?

Diagnostic trouble code (DTC) P0349 stands for “Camshaft Position Sensor “A” Circuit Intermittent.”

The camshaft position sensor measures the camshaft’s rotational position and informs the PCM when a cylinder is on its compression stroke.

If the sensor fails or the reference pulse is interrupted, some injection systems could shut down. In some cases, the injectors could also pulse simultaneously.

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Once the camshaft position sensor is unable to send any data to the PCM, it will log a code P0349.

Note: The definition of code P0123 might be different depending on the vehicle manufacturer. Consult the appropriate repair manual or repair database for the exact code definition.

What are the Common Causes of the P0349 Code

  • Damaged tone ring
  • Camshaft position sensor failure
  • Powertrain control module failure
  • Intermittent open in the ground or signal circuit to the camshaft position sensor
  • Intermittent open in the power supply circuit to the camshaft position sensor
  • Intermittent short to ground in the power supply circuit to the camshaft position sensor

What are the Common Symptoms of the P0349 Code

How to Diagnose the P0349 Code

DTC P0349 is a generic powertrain code that can be logged in various makes and models. While this might be the case, keep in mind that the steps for diagnosis and repair varies from one vehicle to another.

If you’re not familiar with the process of diagnosing trouble codes, it’s a good idea to go to the nearest repair shop and have a certified mechanic do the job for you. But if you think you’re equipped with the right know-how, then you can go ahead and do it yourself.

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To help you out, here’s a video that shows what the diagnostic process for a P0349 code might involve:

How to Fix the P0349 Code

Attempting to fix a P0349 code can be confusing if you don’t have the right tools and information. If you’re not confident with your DIY skills yet, it might be best to leave the job to the pros.

If you plan on clearing this code on your own, make sure you’re equipped with the right manuals. Guides like those from Chilton or an ALLDATA subscription contain vehicle-specific repair information, so you might want to check those out before you start.

About The Authors
Written By Automotive and Tech Writers

The CarParts.com Research Team is composed of experienced automotive and tech writers working with (ASE)-certified automobile technicians and automotive journalists to bring up-to-date, helpful information to car owners in the US. Guided by CarParts.com's thorough editorial process, our team strives to produce guides and resources DIYers and casual car owners can trust.

Reviewed By Technical Reviewer at CarParts.com

Richard McCuistian has worked for nearly 50 years in the automotive field as a professional technician, an instructor, and a freelance automotive writer for Motor Age, ACtion magazine, Power Stroke Registry, and others. Richard is ASE certified for more than 30 years in 10 categories, including L1 Advanced Engine Performance and Light Vehicle Diesel.

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.

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