# EPC Light is On



## skotti (Sep 27, 2005)

Scenario:
Driving about 65 MPH, wet roads- possible ice, but I don't believe I hit any. The car suddenly feels like it is losing power. The EPC and ESP (icon w/ car and squiggly tire tracks) lights come on. I limp over to the side of the road, shut down, open up the manual. Restart the car; ESP light is out, EPC light is on. I call the dealership, make an appointment to bring it in tomorrow morning. Car feels normal at this point. Drove back up to highway speeds, smoothly accelerated from 60 to 80, no issues. Car seems normal.
Any ideas on what might cause this? Service rep thinks it will likely reset (go out) itself before tomorrow. I will still want to know what caused this, so will still bring it in for VAGCOM.
TIA


_Modified by skotti at 11:09 AM 1-31-2009_


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## grubble (Oct 28, 2007)

*Re: EPC Light is On (skotti)*

Possibly black ice? It's snowing up here in the Northeast (I'm currently in CT) and raining too so not the best of conditions to be driving in. 
But the EPC light being still on is odd since it kicks in during low traction situations and turns off when not (at least in my past experience driving in rainy conditions).
Stay safe out there kids!


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## skotti (Sep 27, 2005)

*Re: EPC Light is On (grubble)*

Can someone tell me the function of 'EPC'? The manual says it means Electronic Power Control, but doesn't really say the function of EPC.


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## Slickvic (Apr 25, 2006)

*Re: EPC Light is On (skotti)*


_Quote, originally posted by *skotti* »_Can someone tell me the function of 'EPC'? The manual says it means Electronic Power Control, but doesn't really say the function of EPC.

It controls the power of your engine....thru the use of electronics.
Specifically it can control reduce your throttle if it senses that too much power is being applied to the wheels.


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## skotti (Sep 27, 2005)

*Re: EPC Light is On (Slickvic)*


_Quote, originally posted by *Slickvic* »_
It controls the power of your engine....thru the use of electronics.
Specifically it can control reduce your throttle if it senses that too much power is being applied to the wheels. 

Could Revo software have caused this problem?


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## gCHOW (May 26, 2006)

*Re: EPC Light is On (skotti)*

maybe RS4 reps caused this?


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## gCHOW (May 26, 2006)

*Re: EPC Light is On (gCHOW)*

so the EPC light came on and then you moved over the curb. shut down. restarted the car and the EPC light was off?
this might be cuz you hit a slippery patch on the road and your tires started spinning. the EPC control will then ease off power to the wheels (which i assume is what you experienced) until your car is stabilized (which is when you restarted the car).


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## skotti (Sep 27, 2005)

*Re: EPC Light is On (gCHOW)*


_Quote, originally posted by *gCHOW* »_so the EPC light came on and then you moved over the curb. shut down. restarted the car and the EPC light was off?
this might be cuz you hit a slippery patch on the road and your tires started spinning. the EPC control will then ease off power to the wheels (which i assume is what you experienced) until your car is stabilized (which is when you restarted the car).


No, the EPS light stayed on (and has stayed on all day). The ESP light went out after I shut down. 
And I have Caleral


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## gCHOW (May 26, 2006)

*Re: EPC Light is On (skotti)*


_Quote, originally posted by *skotti* »_And I have Caleral









LOL, i know. i'm just going with the RS4 theme of the day.
but yea.. not sure whats going on. funny to me how its been on this whole time. i say get to the dealership next chance you get so they can scan the car for codes.
and no, i dont believe revo coulda caused this.


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## skotti (Sep 27, 2005)

*Re: EPC Light is On (gCHOW)*

Yeah, noticed the RS4 rep theme... wow, that's something new








I spoke with the shop that did my Forge DV install- they think it could possibly be the PCV...that, among a hundred other things.
I am taking it to the delaer tomorrow (still under warranty).
Stay tuned.


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## skotti (Sep 27, 2005)

*Re: EPC Light is On (skotti)*

Update:
Dealer couldn't find any codes to cause the EPC light to come on, reset it, test drove to duplicate conditions, and all was fine.
Next day, I am driving on the highway, and I notice as I accelerate, I hear a steady hissing noise coming from my Forge spacer (I also have Forge DV). Thinking big vaccum leak at this point (can anyone confirm my thinking, having heard this noise?). Then on highway, car does the same thing- EPC and ESP lights, loss of power, shut down/restart, all is good except EPC light is on.
Happens a couple more times in the next 20 minutes. Each time, it is while I am WOT (with hissing noise steady as I am trying to accelerate). Third time it happens, I have a CEL as well (steady).
Then, 30 minutes later while stopped at light- turns green- as soon as I try to go, car dies. I restart it quickly and proceed- still with EPC and steady CEL. This happens several times, either while slowing down, or starting from a stop (does not happen every time).
At one light, I shut the car down and restarted it- the CEL reset itself, and has been out since.
I am thinking I have a large vaccum leak that is causing the problem- but I'm a noob, so what do I know? I know a PCV failure can cause a vaccum leak- but enough to go to 'limp mode' and shut the car down?
I do have REVO software.
Also- how many different version of the PCV on the 2.0T are there, since introduction to the USA? My car is a 2006, picked up in June 2005. If the problem is the PCV, I assume the dealership will try not to cover it because of REVO software. Again, IF it is the PCV: I'd like to 'bargain' with them. If the PCV is a known issue, then they can't say with any certainty that the software caused the problem- as they can't say for sure it was a faulty PCV.
Perhaps I can negotiate a price with them, seeing as they are responsible for damaging my Votex lip (and are replacing it for me, their dime)>


_Modified by skotti at 11:09 AM 1-31-2009_


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## terje_77 (Dec 19, 2005)

*FV-QR*

Hey dude, maybe you should post this on the engine forum. A lot of knowledge over there.
http://forums.fourtitude.com/zeroforum?id=739


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## skotti (Sep 27, 2005)

*Re: FV-QR (terje_77)*


_Quote, originally posted by *terje_77* »_Hey dude, maybe you should post this on the engine forum. A lot of knowledge over there.
http://forums.fourtitude.com/zeroforum?id=739

Good idea http://****************.com/smile/emthup.gif -- I don't go there nearly enough!


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## skotti (Sep 27, 2005)

*Re: FV-QR (skotti)*

Resolution: NGP Racing in Lorton, VA (BIG Fan of that shop- highly recommend them to everyone in NoVA region)- they found a small break in the hose on the Forge DV. R&R, clear codes, life is good


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## krazyboi (May 19, 2004)

*FV-QR*

Woot!


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## grubble (Oct 28, 2007)

*Re: FV-QR (skotti)*

Great news. Is the hose part of the Forge DV kit or an Audi OEM part?


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## krazyboi (May 19, 2004)

*FV-QR*

Yea, he told me it was the line. It was replaced, code cleared...all is well.


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## skotti (Sep 27, 2005)

*Re: FV-QR (grubble)*


_Quote, originally posted by *grubble* »_Great news. Is the hose part of the Forge DV kit or an Audi OEM part?

The hose is part of the Forge kit.


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## grubble (Oct 28, 2007)

*Re: FV-QR (skotti)*


_Quote, originally posted by *skotti* »_
The hose is part of the Forge kit.

Sounds like they need to use a better material for the hoses!


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## skotti (Sep 27, 2005)

*Re: FV-QR (grubble)*


_Quote, originally posted by *grubble* »_
Sounds like they need to use a better material for the hoses!

About a 99% chance it was damaged either prior to, or during, the install. Very unlikely it was a material failure while in use.


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