How to Solve P0726 Engine Speed Input Circuit Malfunction

If you’ve encountered the P0726 error code, which indicates an Engine Speed input circuit malfunction, it’s important to address it promptly to ensure the proper functioning of your vehicle’s engine. In this article, we’ll guide you through the process of diagnosing and resolving this issue.

By following the step-by-step instructions provided, you’ll be able to tackle the problem like an experienced car expert. So, let’s dive in and get your engine back on track!

Understanding P0726 Error Code

The P0726 error code refers to a malfunction in the Engine Speed input circuit. The Engine Speed sensor is responsible for monitoring the rotational speed of the engine crankshaft. When this sensor fails or encounters an issue, it triggers the P0726 error code. Several factors can contribute to this problem, including faulty wiring, a damaged sensor, or issues with the vehicle’s computer system.

When the Engine Speed input circuit malfunctions, it can have adverse effects on the vehicle’s performance. The engine may experience misfires, hesitation, or reduced power output. Ignoring this error code can lead to further damage to the engine or other related components, making it crucial to address it promptly.

car vertical

Diagnostic Process

To diagnose the P0726 error code accurately, follow these steps:

Step 1: Checking for Associated Trouble Codes

Using a reliable scan tool, check for any additional trouble codes that may be stored in the vehicle’s computer system. These codes can provide valuable insights into potential underlying issues.

Step 2: Visual Inspection of the Engine Speed Sensor and Wiring

Inspect the Engine Speed sensor and its wiring for any visible signs of damage, such as frayed wires or loose connections. Ensure that the sensor is securely fastened and properly aligned.

Step 3: Testing the Engine Speed Sensor with a Multimeter

Using a multimeter, test the Engine Speed sensor for proper voltage and continuity. Refer to the vehicle’s repair manual for the specific resistance values and voltage ranges.

Step 4: Inspecting the Vehicle’s Computer System

Check the vehicle’s computer system for any signs of malfunction or damage. Ensure all connections are secure and free from corrosion. If necessary, consult a professional or refer to the vehicle’s repair manual for guidance on testing the computer system.

Step 5: Clearing the Error Code and Retesting

Once you have identified and addressed any underlying issues, clear the error code from the vehicle’s computer system. Take the vehicle for a test drive and monitor its performance to ensure that the P0726 error code does not reoccur.

Repair and Solutions

Based on the diagnostic process, here are some solutions to resolve the P0726 error code:

Solution 1: Cleaning or Replacing the Engine Speed Sensor

If the Engine Speed sensor is dirty or faulty, clean it using an appropriate sensor cleaner or replace it with a new one. Follow the manufacturer’s instructions for sensor removal and installation.

Solution 2: Repairing or Replacing Damaged Wiring

If you find any damaged wiring during the visual inspection, repair or replace it as necessary. Ensure all connections are secure and properly insulated.

Solution 3: Addressing Issues with the Vehicle’s Computer System

If the problem lies within the vehicle’s computer system, consult a professional or refer to the vehicle’s repair manual for guidance on resolving computer-related issues.

Solution 4: Resetting the Engine Control Unit (ECU)

In some cases, resetting the Engine Control Unit (ECU) may resolve the P0726 error code. Disconnect the vehicle’s battery for a few minutes, then reconnect it. This process will reset the ECU and clear any stored error codes.

Preventive Measures

To prevent the occurrence of the P0726 error code or similar issues in the future, consider the following preventive measures:

  • Schedule regular maintenance and inspections for your vehicle, including sensor checks and cleaning.
  • Keep the engine area clean and free from debris to prevent damage to the Engine Speed sensor and wiring.
  • Regularly inspect the wiring and connections for any signs of damage or wear. Replace any damaged components promptly.

Tips and Tricks

Here are some additional tips and tricks to help you navigate the diagnostic and repair process:

  • Utilize a scan tool to retrieve and interpret error codes accurately. This will provide valuable information for troubleshooting.
  • When replacing the Engine Speed sensor, follow the manufacturer’s instructions to ensure proper installation and alignment.
  • Double-check all connections and wiring during the repair process to avoid potential issues down the line.


By following the steps outlined in this article, you can effectively diagnose and resolve the P0726 Engine Speed input circuit malfunction. Addressing this issue promptly will help maintain the optimal performance of your vehicle’s engine. Remember to perform regular maintenance and inspections to prevent similar problems in the future. Now, put your car expert hat on and get ready to tackle any car problem that comes your way!


Q1: Can I continue driving my vehicle with the P0726 error code?

A1: While it may be possible to drive your vehicle with the P0726 error code, it is not recommended. Ignoring the error code can lead to further damage to the engine or related components. It’s best to address the issue promptly.

Q2: How much does it cost to replace an Engine Speed sensor?

A2: The cost of replacing an Engine Speed sensor can vary depending on the make and model of your vehicle. It’s advisable to consult with a professional or check with local auto parts stores for accurate pricing.

Q3: Can I reset the P0726 error code by disconnecting the battery?

A3: Disconnecting the vehicle’s battery can sometimes reset the Engine Control Unit (ECU) and clear error codes. However, it’s important to address the underlying issue causing the error code to prevent it from reoccurring. If the error persists, further diagnosis and repairs may be necessary.