How to Solve P0709: Transmission Range Sensor Circuit High Input

As a car owner, encountering issues with your vehicle can be frustrating.

One common problem that you may come across is the P0709 error code, which refers to the transmission range sensor circuit high input. In this article, we will provide you with a step-by-step guide on how to solve this issue and get your car back on the road.

Understanding P0709:

Before we dive into the solution, it’s important to understand what P0709 means.

The transmission range sensor (TRS) is responsible for sending signals to the engine control module (ECM) about the gear position. When the TRS circuit detects a high input, it triggers the P0709 error code, indicating a potential issue with the sensor or its wiring.

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Symptoms of P0709:

When your car experiences a P0709 error, you may notice certain symptoms.

These can include erratic shifting, difficulty shifting gears, the transmission not engaging properly, or the vehicle not starting at all. If you encounter any of these signs, it’s essential to address the problem promptly.

Causes of P0709:

There are several possible causes for the P0709 error code. It can be attributed to a faulty transmission range sensor, damaged wiring or connectors related to the sensor, a malfunctioning ECM, or even a low battery voltage. Identifying the root cause is crucial in resolving the issue effectively.

Diagnosing P0709:

To diagnose the P0709 error code, you will need a few tools such as a multimeter and a code reader or scan tool. Follow these steps to identify the cause:

Step 1: Check the wiring

Inspect the wiring harness connected to the transmission range sensor. Look for any signs of damage, such as frayed wires or loose connections. Ensure that the wiring is securely connected and free from any debris or corrosion.

Step 2: Inspect the sensor

Visually examine the transmission range sensor for any physical damage or signs of wear. Ensure that it is properly mounted and aligned. If you notice any issues, consider replacing the sensor.

Step 3: Test the voltage

Using a multimeter, test the voltage of the transmission range sensor. Follow the manufacturer’s instructions to perform this test accurately. Compare the readings with the specifications provided in your car’s service manual. If the voltage is outside the recommended range, it may indicate a faulty sensor.

Step 4: Replace the sensor

If the previous steps didn’t resolve the issue, it may be necessary to replace the transmission range sensor. Consult your car’s service manual or seek professional help to ensure the correct installation of the new sensor.

Step 5: Clear the fault codes

After resolving the P0709 error code, use a code reader or scan tool to clear the fault codes stored in the ECM. This will reset the system and allow you to verify if the issue has been successfully resolved.

Preventing P0709:

To prevent the recurrence of the P0709 error code, follow these preventive measures:

  1. Regularly inspect the wiring and connectors related to the transmission range sensor for any signs of damage.
  2. Ensure that the battery voltage is maintained at the recommended level to prevent voltage-related issues.
  3. If you notice any symptoms of the P0709 error code, address them promptly to avoid further complications.


Dealing with the P0709 error code can be challenging, but by following the step-by-step guide outlined in this article, you can effectively solve the transmission range sensor circuit high input issue. Remember to diagnose the problem accurately, check the wiring and sensor, test the voltage, replace the sensor if necessary, and clear the fault codes. By taking these actions and implementing preventive measures, you can keep your vehicle running smoothly and avoid future transmission-related problems.


Q1: Can I fix the P0709 error code myself, or should I seek professional help?

A1: While it’s possible to address the P0709 error code yourself, it’s recommended to have some knowledge and experience in car repairs. If you’re unsure or uncomfortable with the diagnostic and repair process, it’s best to consult a professional mechanic.

Q2: Will resetting the fault codes resolve the P0709 issue permanently?

A2: Resetting the fault codes will clear the immediate issue and allow you to verify if the problem has been resolved. However, if the underlying cause is not addressed, the error code may reappear. It’s essential to diagnose and fix the root cause to prevent future occurrences.

Q3: Are there any other error codes related to transmission range sensor issues?

A3: Yes, there are other error codes that can indicate problems with the transmission range sensor, such as P0705 (Transmission Range Sensor Circuit Malfunction) and P0706 (Transmission Range Sensor Circuit Range/Performance). If you encounter these codes, similar diagnostic steps can be followed to identify and resolve the issues.

Remember, if you’re unsure or uncomfortable with any aspect of the diagnostic or repair process, it’s always best to consult a professional mechanic who can provide expert guidance and assistance.