What Does The EPC Warning Light Mean?
If you own an Audi or Volkswagen, you have probably seen the EPC warning light illuminate on your dashboard. We are going to go over what the EPC light does, why the light would come on and how to fix it. When we are done, you will know exactly what to do if this light comes on and how you can take care of it.
The EPC Light
The EPC light is another warning that might pop up on your dashboard. It’s letting you know you have an issue with the Electronic Power Control system or EPC. When the light comes on, you have an issue with your car’s throttle system.
In many cases, the EPC light will come on at the same time as the Engine, ABS, or ESP light, depending on what the problem is. The EPC system is managed by the following units, engine control, brake control, transmission control and steering control unit.
Why Would The EPC Light Come On?
The most common reasons would be a throttle body failure, a damaged ABS sensor, a cracked ABS ring, a bad brake pressure sensor or a damaged brake pedal switch. The light might be caused by wiring issues or various other electrical problems.
Below you will find the most common reasons for the EPC Warning light:
Throttle Body Failure
The throttle body dictates how much air should enter the engine when you hit the gas pedal. It uses the throttle body to control the engine power and if there is a problem with the throttle body, the EPC system cannot function properly. The majority of body throttles are electric and if there is an issue, it will light up the engine check light and the EPC light will appear on your dashboard.
A Failed Brake Pedal Switch
The brake pedal switch or brake light switch will let you know when you have hit the brake pedal and the car should activate the brake lights. It’s also used for other functions including the cruise control system or the EPC system.
One big problem is if there is a problem with the brake pedal switch, the EPC system will not recognize when you press or do not press on the brake pedal. Therefore, it will illuminate the EPC light and record a fault code.
A Damaged ABS Sensor
The ABS sensors register the acceleration of the wheels. It takes this information for the ABS system as well as other systems that use the information and the EPC system is one of those systems.
The ABS sensors are located on the wheel hubs and are continually exposed to dirt, water, and dust which can lead to failure. It can cause problems with the ABS reluctor ring where the ABS sensor measures the speed.
A Failed Brake Pressure Sensor
If you have a Volkswagen and the EPC light comes on your dashboard, there is a good chance the brake pressure sensor failed. The brake pressure sensor operates like a brake light switch but not only does it measure On/Off, it measures the brake pressure you have applied to the brake pedal.
If the brake pressure sensor has to be replaced, it can be somewhat difficult as it sits inside the ABS control module. In many cases, you will have to replace the entire ABS control module if you have a problem with the sensor. Keep in mind, a replacement can be expensive.
A Damaged Steering Angle Sensor
You will find the steering angle sensor located behind your steering wheel and it is used to measure what position the steering wheel is in. The EPC system will take this information to determine which direction you have turned the steering wheel and then correct the brake force using this information.
In order to turn the steering wheel, there is a clock spring where the wires to the steering wheel angle sensor and steering wheel buttons go. The clock spring has been known to fail and if it does, it might look like a problem with the steering angle sensor.
A Faulty Engine Sensor
The EPC system uses many different engine sensors to work correctly and if there is a problem with one of them, it could result in the EPC warning light. It’s important that you read the trouble codes when you see this light in order to pinpoint where the problem initiated.
There are certain sensors that trigger the EPC light including the MAF sensor, the IAT sensor, the ECT sensor or the O2 sensor. We will give you more information to help you find out which sensor is causing the EPC warning light to come on.
Due to all the electronic wiring in your car, there is a good chance that there is a wiring problem that will cause the EPC to come on. Wiring problems can be difficult to locate unless you are already familiar with the vehicle wiring.
The most common issues are broken or corroded electrical contacts or burned-out contacts. If you have tried everything but can’t figure it out, you should contact a professional technician to help you.
To switch of the Volkswagen EPC light, you will have to read the trouble codes using an OBD2 scanner. Once you understand the trouble codes, you will have to continue to troubleshoot these codes. Just guessing will only be a waste of your time and money.
The Trouble Codes
When you have an EPC light come on, you need to read the trouble codes from the engine control module and the ABS control module using your OBD2 scanner. If the EPC warning light is on, there could be one or several trouble codes stored away in one of these control units.
Newer cars have advanced onboard diagnostic systems. If there is a warning light on your dashboard, there is a fault code stored in one of the control modules. You should not try to guess and end up replacing the wrong parts. Save time and money by reading these error codes.
You will have to scan the engine control unit, ABS control unit, steering control and transmission control to find the trouble codes. You can use your OBD2 scanner to read the trouble codes from your home.
The least expensive diagnostic scanners can only read the engine control module. That means the issue could be in other control modules as well. That means you will have to get a more advanced diagnostic scanner or visit Volksmaster for a full diagnostic reading.
Check Your Brake Light Switch
The brake light switch is one of the most standard reasons why the EPC light will turn on and is very easy to check. Have someone hit the brake pedal while you check the brake lights on the car. If there are no brake lights, there is a good chance that the brake light switch is faulty.
Keep in mind, there are many cars that have two different currents in the brake light switch. Therefore, even if the brake lights work there is a possibility that the switch is still bad. Your best option is to diagnose it with a scan tool.
Check The Sensor Data
If you are using a diagnostic scanner but still can’t find any good trouble codes to continue with, you will need to check the sensor data. Check the values from the brake pressure sensor to make sure they are genuine.
Also, you should check the sensor data from all the other engine sensors and the sensors related to the brake and EPC system.
Visit A Professional Mechanic
There’s no doubt, EPC systems can be difficult to diagnose correctly without the right tools or knowledge. If you performed all the basic steps but still couldn’t figure out what was going on, it’s probably time to visit a professional mechanic who has had experience with this problem.
If The EPC Light Is On, Is It Dangerous To Drive?
It can be dangerous to drive with the EPC light on if you do not know what’s causing the problem. When the light is on, there may be several restricted functions taking place in your car. Either fix the problem as soon as possible or visit Volksmaster.
The EPC system is joined to the engine, steering, and brake systems. This can lead to engine damage or even cause a serious accident due to a lack of brake and steering functions. When the EPC light shows up on your dashboard, book your car in for a checkup as soon as possible.
In most cases, the EPC system will not cause damage to your car if you drive carefully. On the other hand, the problem could be severe so your best option is to play ot safe and book your car in for a diagnostic.
FAQs Regarding EPC Light
What Does the EPC Light Mean on my vehicle?
The EPC warning light on your vehicle means there is an issue with the Electric Power Control system. The EPC system controls the throttle including the throttle body, accelerator pedal, cruise control and traction control.
Can Misfiring cause the EPC light to come on?
Misfiring can cause the EPC light to come on, indirectly. If the engine misfires, it will impede the engine’s performance and in most situations, the check engine light will come on. Also, if there is a problem with the engine system, it will trigger the EPC light.
Will the EPC Warning Light Cause a Loss of Power?
Yes, as the EPC warning light controls the throttle system it can cause a sudden loss of power. There’s a chance you cannot even rev the engine when the EPC light comes on.
What will it cost to repair the EPC light?
There is no fixed price to repair the EPC light because there could be several issues that caused the problem to begin with.
Is The EPC light a serious issue?
Yes, due to the various issues that could cause the EPC light to come on, it could be a serious problem. It’s really important to diagnose what is causing the light to come on before you continue driving.
Even though the EPC system might seem like a simple fix, it’s an advanced system that works with so many different systems and it can be quite difficult to pinpoint where the problem is originating.
With information from this article, you should be able to at least begin a diagnosis to find out why your EPC light has come on. If you have the tools and knowledge to fix the problem yourself, you will save time and money. On the other hand, if this is over your head, you must get your car to a professional mechanic to get it straightened out as soon as possible.
The EPC system is a very important part of your car’s operations.
If your EPC warning light is illumiated or you are considering a service, repair or MOT you can book your vehicle in to one of our 4 branches by using the simple form below or give us a call at Oldham 0161 624 5060, Heywood on 01706 622633, Bury 0161 761 3030 and our Oldham Van Centre 0161 628 5270.
Arranging Your Service
Drop your car off
Simply drop your car off with us between 8am and 10am and in most cases your vehicle will be ready for collection the same day between 3.30 and 5.30. Outside these hours you are welcome to park.
Wait with your car
Most servicing and repair work can be done while you wait. If this is your preference we have a superb waiting area equipped with free hot and cold drinks and a interesting viewing area where you can watch our trained technicians working on your vehicle.
If your vehicle needs to stay with us for 1 day or longer then you are able to pre-book one of our courtesy vehicles to keep you mobile.
Pick up / drop off
The ultimate hassle free solution; one of our drivers will arrange to collect your vehicle from your home or place of work at a pre-arranged time and then return your vehicle when the work is complete. Our service advisors will contact you when the vehicle arrives on site during the day to discuss the progress of the work and then advise you of the time you can expect your vehicle back. Contact our service advisors for more details.