P0671 code — how to fix error fast

If you own a diesel-powered car, the P0671 code is one of the most common OBD2 codes that may appear. If it does, the worst thing you could do is overlook it and keep driving until it causes the engine to stop cranking properly.

The most important thing is to know more about the P0671 code meaning, so that’s exactly what our guide will give you. Our team has worked tirelessly to find out the reasons behind this code, ways of diagnosing the root cause, and fixing it in a way that prevents the code from re-appearing.

Why you can trust REREV’s OBD2 code advice: Our automotive expert researchers with experienced mechanics undertakes a thorough research methodology to deliver precise insights on OBD codes. Find out more about OBD2 codes research process..

What does the P0671 code mean?

The P0671 code is a diagnostic trouble code that indicates there is an issue with the glow plug control circuit in one of the cylinders. The glow plug control circuit is responsible for heating the glow plugs, which helps to start the engine in cold weather conditions. If the control circuit is malfunctioning, it can cause the glow plugs to not heat up properly, which can result in difficulty starting the engine.

It’s important to understand the P0671 code as it can lead to significant issues with your car if not addressed promptly. If left untreated, it can cause damage to the engine and other components of the vehicle, which can result in costly repairs.

What causes the P0671 code?

Several potential causes can trigger the P0671 code. One of the most common causes is a faulty glow plug control module. Other potential causes include electrical issues and wiring problems, but it takes knowing about all the possible causes in a bit more detail to figure out a solution:

Problems with the glow plug relay

The glow plug relay is responsible for controlling the flow of electricity to the glow plugs. A malfunctioning relay can cause issues with the glow plug system, leading to the P0671 code.

Malfunctioning glow plugs

If one or more glow plugs are faulty, it can cause issues with the entire system and trigger the P0671 code.

Wiring issues

Damaged or broken wiring in the glow plug control circuit can cause problems with the system and trigger the P0671 code.

Malfunctioning PCM

The powertrain control module (PCM) is responsible for controlling various systems in the vehicle, including the glow plug system. If there is an issue with the PCM, it can cause problems with the glow plugs and trigger the P0671 code.

Which car models does the P0671 code affect the most?

The P0671 code can affect many different car models, but some models are more susceptible to the issue. We were curious to explore more about these models and what makes them more prone to the code than other cars, so here’s what we’ve found:

• Ford Super Duty: The Ford Super Duty is a popular heavy-duty pickup truck that is commonly used for towing and hauling. It is equipped with a diesel engine that uses glow plugs to start up, making it more likely to experience issues with the glow plug control circuit.
• Chevy Silverado: The Chevrolet Silverado is another popular heavy-duty pickup truck that is commonly used for work and construction. It is equipped with a diesel engine that also uses glow plugs, making it more likely to experience issues with the glow plug control circuit.
• Dodge RAM: The Dodge Ram is a full-sized pickup truck that has been popular among consumers for many years. It also uses a diesel engine that relies on glow plugs, making it more likely to experience issues with the glow plug control circuit.

How to diagnose the P0671 code

To diagnose the P0671 code, you will need to perform several tests. First, you can use a diagnostic scanner to retrieve the code and any other codes that may be present. Some of the other options could be used by a mechanic, while others can be used by you without even having any professional equipment:

Visual inspection

You can start by visually inspecting the glow plug control circuit and looking for any obvious signs of damage or wear. This includes checking the wiring, connectors, and other components for any signs of frayed wires, corrosion, or other issues.

Electrical testing

This one can be done by a qualified professional to use a multimeter or other electrical testing tool to check the voltage and resistance of the glow plug control circuit. They may also perform a voltage drop test to check for any issues with the circuit’s power supply.

Testing related components

If the issue is not immediately apparent, a mechanic may need to test individual components of the glow plug control circuit, such as the glow plugs themselves or the glow plug relay. This involves removing these components from your vehicle and testing them using specialized equipment.

How to fix the P0671 code

Fixing the P0671 code will depend on the underlying cause of the issue and it mostly involves replacing the faulty components. Still, it takes knowledge about all the possible solutions that you can apply once you’ve properly diagnosed the code, so here’s what you can do:

Deal with the faulty glow plug

If one or more glow plugs are found to be faulty during the diagnostic process, they will need to be replaced. This involves removing the old glow plugs and installing new ones in their place.

Repair damaged wiring

If damaged wiring is identified as the cause of the P0671 code, it will need to be repaired or replaced. This may involve splicing in new wiring, replacing entire sections of wiring, or repairing damaged connectors.

Replace the faulty glow plug relay

If the glow plug relay is found to be faulty, it will need to be replaced. This involves removing the old relay and installing a new one in its place.

Replace the PCM

In rare cases, the powertrain control module (PCM) may be the cause of the P0671 code. If this is the case, the PCM will need to be repaired or replaced.

How to prevent the P0671 code

To prevent the P0671 code from appearing, it’s essential to maintain your car properly. Routine maintenance tasks like the following can help quite a bit:

• Regular oil changes
• Tune-ups
• Checking the glow plug circuit
• Make sure that the glow plugs are properly maintained

Properly maintaining your car’s electrical system can also help to prevent the P0671 code from appearing. This includes checking the battery and alternator regularly and ensuring that all wiring and connectors are in good condition.

Our take

In conclusion, the P0671 code is an important code to understand as it can indicate a significant problem with your car. By understanding the code, its causes, and how to prevent it, you can keep your car running smoothly and avoid costly repairs.

We hope that our team managed to pass some of our expert knowledge on dealing with the code to you through this guide so you can use it for the benefit of your car.