How to Diagnose and Solve C1859 PRNDL Input #2 Circuit Failure Issues

As a car enthusiast, there’s nothing more satisfying than rolling up your sleeves and getting your hands dirty to fix a car problem. Today, we’re going to tackle a common issue that many car owners face – the C1859 PRNDL Input #2 Circuit Failure.

Understanding the C1859 PRNDL Input #2 Circuit Failure

Before we dive into the solution, let’s first understand what the C1859 PRNDL Input #2 Circuit Failure is. This error code is related to the transmission control module (TCM) of your vehicle. It indicates a problem with the second input circuit of the Park/Reverse/Neutral/Drive/Low (PRNDL) switch.

What Causes the C1859 PRNDL Input #2 Circuit Failure?

The C1859 error code can be triggered by several factors. These include a faulty PRNDL switch, damaged wiring or connectors, or a malfunctioning TCM.

Diagnosing the C1859 PRNDL Input #2 Circuit Failure

Now that we know what the C1859 PRNDL Input #2 Circuit Failure is and what causes it, let’s move on to diagnosing the problem.

Step 1: Check the Error Code

The first step in diagnosing this issue is to confirm the error code. You can do this by using an OBD-II scanner. This device will read the error codes from your car’s computer and display them on its screen.

Step 2: Inspect the PRNDL Switch

Next, inspect the PRNDL switch for any signs of damage or wear. If the switch is faulty, it will need to be replaced.

Step 3: Check the Wiring and Connectors

Inspect the wiring and connectors that link the PRNDL switch to the TCM. Look for any signs of damage, corrosion, or loose connections.

Step 4: Test the TCM

Finally, test the TCM to ensure it’s functioning correctly. If it’s not, it may need to be replaced or repaired.

Solving the C1859 PRNDL Input #2 Circuit Failure

Once you’ve diagnosed the problem, it’s time to fix it. Here’s how:

Step 1: Replace the PRNDL Switch

If the PRNDL switch is faulty, replace it with a new one. Make sure to follow the manufacturer’s instructions for installation.

Step 2: Repair or Replace Damaged Wiring or Connectors

If you found any damaged wiring or connectors during your inspection, repair or replace them as necessary.

Step 3: Repair or Replace the TCM

If the TCM is malfunctioning, it will need to be repaired or replaced. This is a job best left to a professional, as it involves complex electrical work.

Conclusion

Fixing a C1859 PRNDL Input #2 Circuit Failure can be a challenging task, but with the right tools and a bit of patience, you can do it yourself. Remember, always take safety precautions when working on your vehicle and don’t hesitate to seek professional help if you’re unsure about any step in the process.

FAQs

1. What is a C1859 PRNDL Input #2 Circuit Failure?

A C1859 PRNDL Input #2 Circuit Failure is an error code that indicates a problem with the second input circuit of the PRNDL switch in your vehicle’s transmission control module.

2. What causes a C1859 PRNDL Input #2 Circuit Failure?

This error code can be caused by a faulty PRNDL switch, damaged wiring or connectors, or a malfunctioning TCM.

3. How can I fix a C1859 PRNDL Input #2 Circuit Failure?

To fix this issue, you’ll need to diagnose the problem using an OBD-II scanner, inspect the PRNDL switch, wiring, and connectors, and repair or replace any faulty components.