P0338 DTC Code: Causes, Symptoms, and Solutions


In the world of automotive diagnostics, the P0338 DTC code stands out as one of the most common and troublesome issues faced by vehicle owners. This diagnostic trouble code (DTC) is related to the Crankshaft Position Sensor “A” Circuit High Input. In this article, we will delve deep into the causes, symptoms, and solutions for this code, providing you with a comprehensive understanding of P0338 and how to address it effectively.

Understanding the P0338 DTC Code

Before we dive into the specifics, it is crucial to have a general understanding of what the P0338 DTC code signifies. The OBD-II system in vehicles uses fault codes to identify malfunctions, and P0338 is one such code. It indicates an issue with the crankshaft position sensor circuit, specifically, a high input signal received by the engine control module (ECM) or powertrain control module (PCM).

Causes of P0338 DTC Code

Several factors can contribute to the triggering of the P0338 DTC code. Understanding these causes will help you identify the root of the problem and take appropriate measures to rectify it. Some common causes include:

  1. Faulty Crankshaft Position Sensor: A malfunctioning or damaged crankshaft position sensor is one of the primary causes of the P0338 DTC code. This sensor plays a vital role in providing the ECM/PCM with accurate information about the crankshaft’s position and rotational speed.

  2. Wiring Issues: Damaged or loose wiring connections in the crankshaft position sensor circuit can disrupt the signal transmission and induce a high input condition, leading to the P0338 DTC code.

  3. Sensor Sync Issues: If the crankshaft position sensor is not synchronized properly with the camshaft position sensor, it can generate incorrect signals, triggering the P0338 DTC code.

  4. Faulty ECM/PCM: In rare cases, the P0338 DTC code can be caused by a malfunctioning ECM/PCM, which is unable to process the input signals correctly.

Symptoms of P0338 DTC Code

Detecting the symptoms associated with the P0338 DTC code is crucial for timely diagnosis and repair. Here are some common signs that may indicate the presence of this code:

  • Check Engine Light: The illumination of the check engine light is one of the primary indications of a potential issue. When the P0338 DTC code is triggered, the check engine light will illuminate to draw the driver’s attention to the problem.

  • Engine Performance Issues: The vehicle may experience erratic or rough engine performance, including misfires, stalling, or difficulties with starting the engine.

  • Reduced Fuel Efficiency: A malfunctioning crankshaft position sensor can lead to fuel delivery problems, resulting in decreased fuel efficiency. If you notice a sudden drop in your vehicle’s mileage, it could be attributed to the P0338 DTC code.

  • Unusual Noises: In some cases, a faulty crankshaft position sensor can cause irregular engine noises, such as knocking or ticking sounds. These noises can be an additional symptom of the P0338 DTC code.

Solutions for the P0338 DTC Code

Addressing the P0338 DTC code requires a systematic approach that involves both diagnosis and repair. Here are some potential solutions to consider:

  1. Diagnostic Scanning: Begin by using an OBD-II scanner to retrieve the trouble codes, including the P0338 DTC code. The scanner will provide valuable information to guide your troubleshooting process.

  2. Inspect Wiring and Connections: Conduct a visual inspection of the wiring and connections related to the crankshaft position sensor. Look for frayed wires, loose connections, or any signs of damage. Carefully repair or replace any faulty components discovered.

  3. Test Crankshaft Position Sensor: Perform a thorough inspection and testing of the crankshaft position sensor. Use a multimeter or test equipment recommended by the vehicle manufacturer to measure the sensor’s resistance and output signals. Replace the sensor if it fails to meet the specified values.

  4. Check Synchronization: Verify the synchronization between the crankshaft position sensor and the camshaft position sensor. If they are not aligned correctly, adjust the sensors accordingly to ensure accurate information transmission.

  5. Inspect ECM/PCM: As a last resort, if all other potential causes have been ruled out, consider inspecting or even replacing the ECM/PCM. This step should only be taken after thorough diagnosis and consultation with a professional mechanic.

Frequently Asked Questions

Q1: Can I still drive my vehicle if the P0338 DTC code is present? A1: It is not recommended to continue driving your vehicle if the P0338 DTC code is present. Ignoring the code and the underlying issue can lead to further engine damage, reduced performance, and potential safety hazards.

Q2: How much does it cost to repair the P0338 DTC code? A2: The cost of repairing the P0338 DTC code can vary depending on the specific cause of the issue, the vehicle make and model, and the labor rates in your area. It is best to consult with a trusted mechanic or dealership to get an accurate estimate for your particular situation.

Q3: Can I fix the P0338 DTC code myself? A3: While some DIY enthusiasts may be able to address the P0338 DTC code with the necessary tools and knowledge, it is generally recommended to seek professional assistance. A skilled mechanic will have the expertise and specialized equipment to diagnose the problem accurately and perform the required repairs effectively.


In conclusion, the P0338 DTC code related to the Crankshaft Position Sensor “A” Circuit High Input is a common issue faced by vehicle owners. By understanding the causes, symptoms, and potential solutions outlined in this article, you can take proactive measures to diagnose and address the problem effectively. Remember, proper maintenance, regular inspections, and timely repairs are key to ensuring the optimal performance and longevity of your vehicle.

About author


Meet Sam Mitchell, your experienced and reliable guide in the complex world of car fault codes. With a robust career spanning over 15 years as a professional car mechanic, John has the skills, knowledge, and practical experience to help you navigate car fault issues with confidence.


Leave a Reply