EPC Warning Light: What does it mean and how to fix it?
The EPC warning light (Electronic Power Control) is one of the orange warning lights, in other words, the dashboard lights in the car that generally indicate a particular problem. This system controls the throttle and throttle body, cruise control, traction control, and other engine management functions.
The EPC warning light can appear on the dashboards of gasoline cars, whereas on diesel cars, similar issues are indicated by the glow plug warning light.
Table of Contents
- Why is the EPC warning light on?
- Can I continue driving with the EPC warning light on?
- Summary of possible malfunctions for EPC warning light
- How to fix the EPC warning light?
- EPC warning light and its alternative in the case of diesel engines
- How can you prevent throttle valve failure?
- The car does not start, and the EPC warning light is constantly on
- Check out the video explanation of the EPC warning light
When starting the engine, a lit EPC warning light is not a reason for panic. On the contrary, everything is fine. The problem occurs if the EPC warning light stays on even after starting the engine or comes on while driving. What problems does it indicate, and how to fix them?
Why is the EPC warning light on?
An EPC warning light that keeps illuminated even after starting the engine can signal a malfunction of the throttle system, traction control, cruise control, accelerator pedal, or impurities in the fuel. A less severe problem that can cause the EPC light to come on is a blown bulb, blown fuse, or faulty brake light sensor. In some cases, a low battery may also cause this issue.
Related article - Throttle valve: How it works and its possible malfunctions
The throttle valve is a part of the engine and regulates the intake mixture and the air supply to the engine, affecting your car's performance. The throttle valve is electronically connected to the accelerator pedal - when pressed, the valve opens. There are two potentiometers in the accelerator pedal: if one fails, the other serves as a spare or emergency.
Can I continue driving with the EPC warning light on?
Yes, you can continue driving, as the EPC warning light is not a red warning light, which in many cases, would mean that you should pull over and shut off your engine immediately. However, driving straight to the service center would be best as this warning light should not be underestimated.
Related article - RPM Fluctuation While Driving: These are the 12 most common causes
If the root cause is a malfunction of the throttle system, you may feel that the engine speed fluctuates or shuts down while driving. You may also have a problem starting the car altogether, so it is advisable to solve the problem as soon as possible.
Summary of possible malfunctions for EPC warning light
Let's summarize the reasons why the EPC warning light most often appears on your car's dashboard:
throttle system failure
throttle valve contamination
impurities in the fuel
traction or cruise control system failure
malfunction of the gas pedal and its electronic control
malfunction of the accelerator pedal or throttle potentiometer
failure of the brake switch or engine electronics
a broken light bulb
blown/blown brake light fuse
How to fix the EPC warning light?
The fix for the illuminated EPC warning light highly depends on the problem, though let's summarize the possible fixes:
cleaning or replacing the throttle body
not using cheap fuel from questionable gas stations (applicable when the impurities in the fuel caused the problem)
replacing one of the faulty sensors, such as the mass air flow sensor, engine speed sensor, and others
replacing the brake light switch, blown fuse, or broken light bulb
recharging or replacing the low battery
If there's a failure in electronics, and you think one of the sensors might be causing the issues, we recommend getting your car checked first via car diagnostic.
EPC warning light and its alternative in the case of diesel engines
As already said, the EPC warning light appears in gasoline engines. If similar problems happen in the case of diesel cars, the glow plug warning light will appear. However, this warning light can signal several causes, so we recommend taking your vehicle to a service center for a diagnostic.
How can you prevent throttle valve failure?
An effective way to extend the life of the throttle valve, which may be related to these failures, is its regular maintenance. In addition to a defect in the electronics of this part, it can also become clogged with dirt - in this case, regular cleaning of the throttle valve will help.
If cleaning does not help, the throttle valve needs to be replaced. You can have it replaced at your service center, but if you are at least an amateur mechanic with a bit of time, you can order or buy the throttle body and perform the replacement yourself.
A new throttle valve will not cause any problems, and you have one less thing to worry about maintaining your car.
The car does not start, and the EPC warning light is constantly on
In this case, you should try the following solution - remove the key, lock the car, unlock it, and try to start it.