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Amedee
Amedee, ASE Master Tech
Category: Car
Satisfied Customers: 21783
Experience:  ASE Master Tech advanced level specialist. Wisconsin certified emissions state inspector
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2002 vw jetta: My epc (electronic power control) light is on

Customer Question

2002 vw jetta. My epc (electronic power control) light is on. Manual mentions blinking, it's not blinking. What does it mean? Is it a problem?
Submitted: 6 years ago.
Category: Car
Expert:  Amedee replied 6 years ago.

Installation location of EPC warning lamp

Significance of EPC warning lamp

"EPC" is an abbreviation and stands for Electronic Power Control and means "electronic engine load control".

If malfunctions are recognized in the EPC system during operation of the engine, the Engine Control Module (ECM) switches on the EPC warning lamp.

Function of EPC system
For EPC, the throttle valve is not operated by a cable from the accelerator pedal. There is no mechanical connection between the accelerator pedal and the throttle valve.

The position of the accelerator pedal is communicated to the Engine Control Module (ECM) via two sensors for accelerator pedal position (variable resistances; stored in one housing) that are connected with the accelerator pedal.

The accelerator pedal position (driver's intention) is a main input unit for the ECM.

Operation of the throttle valve occurs via an electric motor (throttle valve actuator) in the throttle valve control module. This is true across the entire engine speed and engine load spectrum.

The throttle valve is operated by the throttle drive according to the instructions of the Engine Control Module (ECM).

With engine at standstill and ignition switched on, the Engine Control Module (ECM) activates the throttle drive precisely according to specifications of the Throttle Position (TP) sensor. This means, if the accelerator pedal is depressed half way, the throttle drive opens the throttle valve to the same degree; i.e. throttle valve is then opened approx. half way.

With engine running (under load), the ECM can open or close the throttle valve independently of the sensor for accelerator pedal position.

This means, for example, that the throttle valve could be fully opened even though the accelerator pedal has only been depressed half way. This has the advantage of preventing torque losses at the throttle valve.

In addition to this, it results in significantly better values relative to emissions and consumption under certain load conditions.

It would be incorrect to think that "EPC" consists of only one or two components. EPC is much more of a system containing all components that contribute to assign, control and monitor the position of the throttle valve, e.g. sensor for Throttle Position (TP) sensor, throttle valve control module, EPC warning lamp, Engine Control Module (ECM).

 

Amedee, ASE Master Tech
Category: Car
Satisfied Customers: 21783
Experience: ASE Master Tech advanced level specialist. Wisconsin certified emissions state inspector
Amedee and 11 other Car Specialists are ready to help you
Customer: replied 6 years ago.
Reply to AMEDEE's Post: Only half of my question was answered, and to be honest....I didn't understand much of this answer. I'm not a grease monkey, the lingo used in this answer was beyond me. I kind of get the very basic idea of what EPC means and does. It's whether it's going to be a problem or not that didn't get answered.
Expert:  Amedee replied 6 years ago.

Sorry for the delay!

This light just means that the system is not getting the right inputs to make a correct decision. It blinks to warn the driver that there is a malfunction.

There could be several reasons this light is blinking. I would rec to have your computer scanned for codes and have this problem taken care of right away. SO yes, to answer your question, it is a problem and may become a bigger problem if not handled correctly right away.

Customer: replied 6 years ago.
I am so sorry that I am such a pain in the ass. As I stated in the original question it is NOT blinking. It will come on and be steady for 5mins then go off and I won't see it again for several hours or days.
Expert:  Amedee replied 6 years ago.

Sounds like your problem is intermittent. This tells me that it is an electrical problem. Sensor, or wiring.

I still rec to get it checked out as soon as possible.

Customer: replied 6 years ago.
Thank you very much for dealing with me. lol. I appreciate it.
Expert:  Amedee replied 6 years ago.
THanks for the accept! Have a good weekend!

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