How to Diagnose and Solve P1651 Fuel Pump Monitor Circuit High Input 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 the P1651 Fuel Pump Monitor Circuit High Input issue. This is a common problem that can cause your vehicle to perform poorly or even fail to start. But don’t worry, I’m here to guide you through the process of diagnosing and solving this issue.

Understanding the P1651 Code

Before we dive into the solution, let’s first understand what the P1651 code means. This code is triggered when the Engine Control Module (ECM) detects an unusually high voltage input from the fuel pump monitor circuit. This could be due to a variety of reasons, including a faulty fuel pump, damaged wiring, or a malfunctioning ECM.

Signs of a P1651 Fuel Pump Monitor Circuit High Input Issue

How do you know if your vehicle has a P1651 issue? Here are some common symptoms:

1. The Check Engine Light is on.
2. The vehicle fails to start or has difficulty starting.
3. The engine stutters or stalls while driving.
4. There’s a decrease in fuel efficiency.

Diagnosing the P1651 Issue

Now that we know the symptoms, let’s move on to diagnosing the problem. Remember, safety first! Always disconnect the battery before starting any electrical work on your vehicle.

Step 1: Check the Fuel Pump

The first step is to check the fuel pump. Listen for a humming sound when you turn the ignition key to the ‘ON’ position. If you don’t hear anything, it could mean that the fuel pump is faulty.

Step 2: Inspect the Wiring

Next, inspect the wiring connected to the fuel pump. Look for any signs of damage, such as frayed wires or corrosion. Damaged wiring can cause high voltage input, triggering the P1651 code.

Step 3: Test the ECM

Finally, test the ECM. This can be done using a digital multimeter. If the ECM is malfunctioning, it may send incorrect signals to the fuel pump, causing the high voltage input.

Solving the P1651 Issue

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

Step 1: Replace the Fuel Pump

If the fuel pump is faulty, replace it. This is a relatively straightforward process, but it can be time-consuming. Make sure to follow the manufacturer’s instructions.

Step 2: Repair or Replace Damaged Wiring

If you find damaged wiring, repair or replace it. This will ensure that the correct voltage is being sent to the fuel pump.

Step 3: Replace the ECM

If the ECM is malfunctioning, it will need to be replaced. This is a more complex task and may require professional assistance.

Conclusion

Fixing a P1651 Fuel Pump Monitor Circuit High Input issue can be a bit challenging, but with the right knowledge and tools, it’s definitely doable. Remember, always prioritize safety when working on your vehicle. If you’re unsure about any step, don’t hesitate to seek professional help.

FAQs

1. What causes a P1651 Fuel Pump Monitor Circuit High Input issue?

This issue is usually caused by a faulty fuel pump, damaged wiring, or a malfunctioning ECM.

2. Can I drive my car with a P1651 issue?

While it’s possible to drive with this issue, it’s not recommended. It can lead to poor vehicle performance and even cause your car to stall while driving.

3. How much does it cost to fix a P1651 issue?

The cost can vary depending on the cause of the problem. Replacing a fuel pump can cost between $300 and $600, while replacing the ECM can cost up to $1,500.