P1814 DTC Code: Understanding and Resolving Transmission Issues


In the world of automotive diagnostics, DTC (Diagnostic Trouble Code) plays a pivotal role in identifying and resolving various issues. P1814 is one such specific DTC code that focuses on transmission-related problems. In this comprehensive article, we will delve into the details of the P1814 DTC code, including its definition, common causes, symptoms, and potential resolutions. So, let’s get started!

What is the P1814 DTC Code?

The P1814 DTC code refers to a transmission-related issue, specifically related to the transmission torque reduction request signal circuit. This code is commonly found in vehicles equipped with automatic transmissions. When the P1814 code is present, it indicates that the powertrain control module (PCM) has detected a problem within the transmission system.

Common Causes of the P1814 DTC Code

  1. Faulty Torque Reduction Request Signal Circuit: This is one of the primary reasons behind the P1814 DTC code. The torque reduction request signal circuit may have a faulty connection, a broken wire, or a malfunctioning sensor, leading to the code being triggered.

  2. Defective Transmission Control Module (TCM): The TCM controls various functions within the transmission system. In some cases, a malfunctioning TCM can result in the P1814 code.

  3. Damaged Wiring or Connectors: Over time, wiring harnesses and connectors can become damaged due to environmental factors or wear and tear. This can disrupt the signal flow within the transmission system, leading to the P1814 DTC code.

  4. Faulty Transmission Solenoids: Solenoids responsible for regulating fluid pressure or shifting gears may become faulty, causing incorrect signals to be sent to the PCM, triggering the P1814 code.

  5. Transmission Fluid Issues: Insufficient or contaminated transmission fluid can negatively impact the overall performance of the transmission system, leading to the P1814 DTC code.

Common Symptoms of the P1814 DTC Code

When the P1814 DTC code is present, you may experience one or more of the following symptoms:

  • Harsh or delayed shifting between gears.
  • Transmission slippage.
  • Transmission staying in a lower gear for too long.
  • Poor acceleration and reduced power.
  • Illuminated Check Engine Light (CEL).
  • Reduced fuel efficiency.

Resolving the P1814 DTC Code

Now, let’s explore some ways to troubleshoot and resolve the P1814 DTC code:

  1. Perform a Visual Inspection: Start by visually inspecting the wiring harnesses, connectors, and transmission-related components. Look for any signs of damage, corrosion, or loose connections. If any issues are detected, repair or replace the affected parts accordingly.

  2. Check the Transmission Fluid: Ensure that the transmission fluid is at the proper level and in good condition. If the fluid appears low or contaminated, perform a flush and fill, or replace it altogether. Regularly maintaining the transmission fluid can prevent potential issues and the recurrence of the P1814 code.

  3. Scan the Transmission Control Module (TCM): Using a professional diagnostic scanner, retrieve the trouble codes stored within the TCM. This will provide additional insights into the specific cause of the P1814 code and any other related issues that may require attention.

  4. Test the Torque Reduction Request Signal Circuit: Perform a thorough electrical test on the torque reduction request signal circuit. This includes checking the integrity of the wiring, connectors, and associated sensors. If any faults are detected, repair or replace the corresponding components accordingly.

  5. Inspect and Test Transmission Solenoids: If all previous steps don’t resolve the issue, inspect and test the transmission solenoids. A malfunctioning solenoid can trigger the P1814 code. Follow the manufacturer’s guidelines or seek professional assistance for proper testing and potential replacement.

Frequently Asked Questions

Q1: Can I continue driving my vehicle with the P1814 DTC code?

A1: It is generally not recommended to continue driving with the P1814 DTC code present. It indicates a problem within the transmission system that might worsen over time. Driving with transmission-related issues can lead to further damage and costly repairs. It is advised to diagnose and address the problem promptly.

Q2: Can a faulty torque reduction request signal circuit cause other issues?

A2: Yes, a faulty torque reduction request signal circuit can lead to various transmission-related problems. Apart from triggering the P1814 code, it can result in harsh shifting, transmission slippage, and reduced overall performance. Resolving the issue promptly will restore the proper functionality of the transmission system.

Q3: Can I reset the P1814 code by disconnecting the battery?

A3: Disconnecting the battery might clear the code temporarily, but it will not fix the underlying issue causing the P1814 DTC code. The code will likely reappear once the fault is detected again. It is essential to diagnose and address the root cause of the problem for a permanent solution.


The P1814 DTC code is an indication of transmission-related issues within a vehicle’s automatic transmission system. Understanding the common causes, symptoms, and potential resolutions is crucial for effective troubleshooting. By following the steps mentioned in this article and seeking professional assistance when necessary, you can address the P1814 code promptly and ensure the smooth operation of your vehicle’s transmission system.

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.


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