P0670 code — how to fix error fast
Recognize the depth of the P0670 code and its potential influence on your car's mechanics.
Drivers who own diesel-powered vehicles may inevitably encounter the P0670 OBD2 code during the lifetime of their car. If this happens to you, it’s important to know how you can handle the situation before the code starts affecting the drivability of your car.
Well, at least that sounds pretty straightforward, but what’s the true P0670 code meaning and how does it affect your car? In this guide, we’ll give you an answer to the question along with a thorough description of each of the potential causes of the code, as well as give you some pointers on diagnosing and fixing the issue.
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 P0670 code mean?
The P0670 code stands for “Glow Plug Control Module Circuit Fault” and indicates that there is a problem with the glow plug control circuit. This code is specific to diesel engines and can affect various systems in your vehicle. Glow plugs are used to preheat the combustion chamber in diesel engines, making it easier to start the engine in cold weather.
The consequences of the P0670 code can vary depending on the severity of the problem. In some cases, you may experience difficulty starting the engine, reduced fuel efficiency, or even engine misfires. If left untreated, the problem can lead to more serious damage to the engine.
What causes the P0670 code?
Even though the code is often related to glow plug performance or the circuit that powers the system, there are some other potential reasons behind this code. We wanted you to know about each and every one of them so you can find an appropriate solution, so here’s a complete list:
Faulty glow plug control module
The glow plug control module is responsible for monitoring the glow plug circuit and sending a signal to the ECM. If the module is faulty, it can cause the code to appear.
Defective glow plugs
If one or more glow plugs are defective, it can cause this code to appear. This can happen if the glow plugs are worn out or damaged, or if there is a problem with the wiring or connections.
Wiring or connection issues
Problems with the wiring or connections in the glow plug circuit can trigger the P0670 code as well, and this is a pretty common issue. It can happen if the wiring is damaged, corroded, or disconnected.
Failed ECM
In rare cases, a failed ECM can be the culprit behind the code. This can happen if there is a problem with the ECM’s circuitry or if it has been damaged by a power surge or other electrical problem.
Which car models does the P0670 code affect the most?
The P0670 code is specific to diesel engines and can affect various makes and models. However, some car models are more likely to be affected by this code than others. Some of the most commonly affected car models include:
- Chevy Silverado: The Duramax diesel engine in some Silverado models may encounter issues with the glow plug control system, leading to this code and other related codes.
- RAM 2500: These pickup trucks feature a Cummins diesel engine that is susceptible to glow plug circuit problems. P0670 may be accompanied by other codes related to glow plug performance.
- Mercedes-Benz Sprinter Van: The Mercedes-Benz Sprinter van is a popular choice for commercial and personal use, but it’s not immune to glow plug issues. The code may appear in Sprinter models with diesel engines that have faulty glow plugs or control circuits.
How to diagnose the P0670 code
It’s not so easy to diagnose this code in terms of finding the exact root cause of the problem. As mentioned, there could be various reasons behind this code’s appearance, so let’s take a look at some of the most commonly used methods of determining the issue:
Visual inspection
You can start by performing a visual inspection of the glow plug circuit, including the wiring and connections. Look for signs of damage, corrosion, or loose connections.
Check glow plug resistance
Use a multimeter to check the resistance of each glow plug. Compare the readings to the manufacturer’s specifications to determine if any of the glow plugs are defective.
Check the glow plug control module
Finally, you can use a scan tool to check for fault codes and to monitor the operation of the glow plug control module. If the module is not functioning properly, it may need to be replaced.
How to fix the P0670 code
Fixing the P0670 code will depend on the underlying cause of the problem, so it’s good that you now know more about the possible reasons behind the code. Here are some steps you can take to repair the issue behind the code so you can clear it for good:
Repair or replace the faulty glow plug control module
If the glow plug control module is faulty, it will need to be replaced. The cost of replacement will vary depending on the make and model of your vehicle, but it’s usually somewhere around $300.
Defective glow plugs
If one or more glow plugs are defective, they will need to be replaced. Keep in mind that this is not done in the same way as spark plug replacement on petrol vehicles and it may cost a bit more to do this, so you should rely on the services of a trusted mechanic.
Wiring or connection issues
Problems with the wiring or connections in the glow plug circuit will need to be repaired or replaced to fix this problem and remove the code. It’s better not to tamper with the wiring yourself if you can rely on a trusted professional to do the repairs.
Failed ECM
If the ECM is faulty, it will need to be replaced. This is a more complex repair that should be performed by a professional mechanic, but we advise you to always double-check this since it’s possible that the module just needs to be reprogrammed.
How to prevent the P0670 code
Preventing the P0670 code requires proper maintenance of your vehicle’s glow plug system. Here are some tips to help prevent the code from appearing:
- Follow the manufacturer’s recommended maintenance schedule for your vehicle
- Use high-quality glow plugs that are designed for your vehicle
- Inspect the wiring and connections in the glow plug circuit regularly
- Replace any damaged or worn components as soon as possible
By following these tips, you can help prevent the P0670 code from appearing and ensure that your vehicle runs smoothly and efficiently.
Our take
Overall, the code P0670 can be a pretty bad one if it affects your glow plug circuit in a way that makes it more difficult to start your car in the winter.
To prevent this, we advise you to follow the steps outlined in this article and make use of the prevention steps so you can ensure that clearing the code goes smoothly and never results in it coming back after some time.
Can I still drive my car with the code P0670?
If the code P0670 appears, you may not be able to drive your car since it affects the performance of the glow plug which is used to pre-heat the combustion chamber in diesel engines, so your vehicle may fail to start in cold weather.
How can I fix the P0670 code?
You can fix and remove the P0670 code by checking the glow plug control module, inspecting the wiring, and the performance of the ECM in your car. We advise you to rely on the services of a trusted mechanic to do the necessary repairs.
How much will it cost to remove the code P0670?
Clearing the code P0670 can cost anywhere from $100 for repairing the connections, to $300 for glow plug module replacement or even higher if the ECM needs to be replaced.
