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P0335 Fault Code: Crankshaft Position Sensor "A" Circuit Malfunction (Causes & Fixes)

Updated: Jan 8

P0335 is a diagnostic trouble code (DTC) standing for "Crankshaft Position Sensor "A" Circuit Malfunction". This fault code could have multiple causes, so it is necessary for a mechanic to accurately diagnose the root cause specific to your vehicle.


If a DTC is associated to the powertrain, an OBD scanner will read it as starting with P, thus the letter "P." Generic fault codes are those of the format P0xxx.

P0335 is a diagnostic code for a malfunction in the crankshaft position circuit, as identified by the OBD-II system.

 

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Meaning of a P0335 Fault Code

The P0335 diagnostic code indicates a problem with the crankshaft position sensor, which is responsible for providing the engine control module with information about the timing of ignition and fuel delivery.


When the powertrain control module (PCM) detects an issue with the crankshaft position sensor, it activates the check engine light on the dashboard and activates failsafe mode.


This code is specifically triggered when the engine control module is unable to detect proper functioning of the crankshaft position sensor, or when there is a problem with the square wave voltage signal being generated by the sensor's reluctor ring.


This P0335 code applies to the crankshaft position sensor "A" bank 1.


How Serious Is It?

P0335 is a serious fault code that may indicate mechanical or electrical issues within the engine. If you notice drivability problems or the check engine light comes on, it is important to have the vehicle repaired as soon as possible.


Continuing to drive a vehicle with this fault code can be dangerous, as it may cause the engine to stop running unexpectedly or result in further damage.


You should avoid driving the vehicle if it displays a P0335 code until it has been properly repaired to prevent a breakdown or further engine damage.


If you notice any issues with the performance of your vehicle, it is important to have it diagnosed to determine the cause and take appropriate action to repair it.


Potential Causes of a P0335 Code

Below is a list of some possible causes of a P0335 diagnostic code.


  1. Open or short in the wiring harness: This may be caused by damaged or frayed wires, loose connections, or corrosion.

  2. Poor electrical connections: These may be caused by loose or dirty terminals, damaged connectors, or corrosion.

  3. Crankshaft position sensor failure: The crankshaft position sensor may fail due to wear, damage, or a malfunction in the sensor itself.

  4. Damaged signal plate: The signal plate, which is located on the crankshaft, may become damaged due to wear, damage, or a malfunction in the plate itself.

  5. Broken timing belt or chain: A broken timing belt or chain can cause the engine to stop running and may require extensive repairs to fix.

  6. Faulty ECM/PCM: The engine control module (ECM) or powertrain control module (PCM) may malfunction due to a software issue, hardware issue, or other problem.

  7. Rough running/misfiring engine: This may be caused by a variety of issues, including problems with the ignition system, fuel system, or other mechanical issues.


Signs & Symptoms of a P0335 Code

The symptoms of a P0335 code can vary widely and may not always be immediately noticeable. Some possible symptoms include the following.


  1. Check engine light: The check engine light may come on when the P0335 code is detected, although it may not always illuminate until the problem has occurred multiple times.

  2. Vehicle stalling or hesitation: The vehicle may stall or hesitate when accelerating, particularly if the crankshaft position sensor is not functioning properly.

  3. Difficulty starting the engine: The vehicle may have difficulty starting if the crankshaft position sensor is not providing the engine control module with accurate information about the timing of ignition and fuel delivery.

  4. Rough running engine: The vehicle may run poorly or exhibit unusual vibrations if the crankshaft position sensor is not functioning properly.

  5. Engine cutting out: In some cases, the engine may stop running unexpectedly if the crankshaft position sensor is not providing the engine control module with accurate information.


Other possible symptoms of a P0335 fault code may include poor fuel efficiency and a lack of engine power. It is important to have the vehicle repaired as soon as possible if you notice any of these symptoms to prevent further damage to the engine.


How Is the P0335 Fault Code Diagnosed?

Diagnosing a P0335 diagnostic code typically involves a series of steps that may require specialised equipment and mechanical knowledge. Below is a list of some common steps that a mechanic may follow to diagnose the cause of a P0335 code.


  1. Use a scan tool to check for any codes stored in the powertrain control module (PCM). This may include current, history, and pending codes, as well as freeze frame data.

  2. Clear any codes that are detected and perform a road test to try to duplicate the symptoms.

  3. Conduct a visual inspection of the crankshaft position sensor and its wiring, looking for signs of damage or wear.

  4. Use the scan tool to monitor the crankshaft position sensor readings and RPM signal. If both of these are within range, test the wiring to see if it is functioning properly.

  5. Test the PCM using manufacturer-specific testing procedures.


If you are not familiar with vehicles or do not have the necessary tools or knowledge to diagnose a P0335 fault code, it is best to take your vehicle to a mechanic for further diagnosis and repair.


Fixing this code at home can be a time and labor-intensive process and may require a higher level of mechanical knowledge than is recommended for beginners.


To assess whether the crankshaft position sensor has failed may wish to test the crankshaft position sensor. This will tell you whether the sensor is the cause of the P0335 code.


Common Mistakes

Proper diagnosis of a P0335 diagnostic code is important to ensure that the root cause of the problem is identified and repaired correctly. Even with experienced technicians, mistakes can be made if all diagnostic steps are not followed in the proper order.


The most common cause of a P0335 code is a faulty crankshaft position sensor, but it is important to check all potential causes to ensure that issues such as a broken sensor ring or timing belt are not overlooked.


Some other potential causes of a P0335 code may include problems with the wiring harness, electrical connections, signal plate, engine control module (ECM) or powertrain control module (PCM), and other mechanical issues.


It is important to follow a thorough diagnostic process to identify the specific cause of the code and take the appropriate steps to repair it.


How to Fix a P0335 Code

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