P1765 Intermediate Speed Sensor (ISS) Malfunction

How to Diagnose and Solve P1765 Intermediate Speed Sensor (ISS) Malfunction Issues


As a car enthusiast, there’s nothing more frustrating than seeing an error code pop up on your dashboard. One such error is the P1765 Intermediate Speed Sensor (ISS) Malfunction. But don’t worry, I’m here to help you understand what this means and how to fix it.

Understanding the P1765 ISS Malfunction

Before we dive into the solution, let’s first understand what the P1765 ISS Malfunction is. The Intermediate Speed Sensor is a crucial component in your vehicle’s transmission system. It monitors the rotational speed of the intermediate shaft in the transmission and sends this information to the Engine Control Unit (ECU). When the ECU detects an irregularity in this data, it triggers the P1765 error code.

Common Symptoms of P1765 ISS Malfunction

Identifying the symptoms of a P1765 ISS Malfunction can help you diagnose the problem early. Some common symptoms include:

1. Check Engine Light is on
2. Difficulty shifting gears
3. Decreased fuel efficiency
4. Unusual noises from the transmission

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Diagnosing the P1765 ISS Malfunction

Now that we know the symptoms, let’s move on to diagnosing the problem. You’ll need an OBD-II scanner for this. Connect the scanner to your vehicle’s diagnostic port and read the error codes. If P1765 appears, you’ve confirmed the ISS malfunction.

Inspecting the ISS and Wiring

After confirming the error code, inspect the ISS and its wiring. Look for signs of damage, corrosion, or loose connections. If you find any, this could be the cause of the malfunction.

Fixing the P1765 ISS Malfunction

Once you’ve diagnosed the problem, it’s time to fix it. Here are some steps you can take:

Replace the ISS

If the ISS is damaged or faulty, it will need to be replaced. This is a job best left to professionals unless you’re comfortable working with your vehicle’s transmission system.

Repair or Replace Damaged Wiring

If the wiring to the ISS is damaged, it will need to be repaired or replaced. This can usually be done with basic tools and a bit of patience.

Reset the Error Code

After fixing the problem, use your OBD-II scanner to reset the error code. If the code doesn’t return, you’ve successfully fixed the problem.

Preventing Future P1765 ISS Malfunctions

Prevention is always better than cure. Regular maintenance and inspections can help prevent future P1765 ISS malfunctions. Keep an eye on your transmission system and address any issues as soon as they arise.


Dealing with a P1765 ISS Malfunction can be a bit daunting, but with the right knowledge and tools, you can diagnose and fix the problem yourself. Remember, if you’re ever in doubt, it’s always best to consult with a professional.


1. What is a P1765 ISS Malfunction?

A P1765 ISS Malfunction is an error code that indicates a problem with the Intermediate Speed Sensor in your vehicle’s transmission system.

2. How can I diagnose a P1765 ISS Malfunction?

You can diagnose a P1765 ISS Malfunction using an OBD-II scanner. If the error code P1765 appears, it confirms the malfunction.

3. How can I fix a P1765 ISS Malfunction?

Fixing a P1765 ISS Malfunction involves replacing the faulty ISS or repairing or replacing damaged wiring. After fixing the problem, use an OBD-II scanner to reset the error code.