I was cruising home on the freeway today and the engine jolted really bad and I lost all throttle response. The EPC light turned on and I pulled over and thought the engine had turned off but the rpm's dropped down to idle speed but the idle was so rough it was shaking the whole car. The weird thing next was that I turned off the ignition and then started the car right up with the engine then running beautifully and the light disappeared. I drove all the way home with no problems. I'd like to understand what the hell happened and if this is likely to happen again.

So EPC stands for electronic power control right? Does this originate from the ecu or is this a sensor related problem? Any help would be greatly appreciated. TIA.

 

I just think your car had a brain fart...A massive brain fart and in refrence to the original question i have no idea.

 

Were you using cruise control? My a4 did that when I had a nasty vac leak (which I didn't know at the time) and I would always use cruise just to save gas. Whenever I would go down this one slope in the road, it would throw the epc light up, every time without fail. My guess is your car ran insanely rich just long enough to scare the car into limp mode

 

Hmm. No, I wasn't using CC. Hopefully it was just some freak occurance. I drove 50 mi. to work this morning with no problems.

 

You should scan for codes on the ECU.

 

Yeah, I'll do that tomorrow. No cel came on when it happened, but I've heard of the ecu storing codes sometimes even though there's no cel. I swear, it scared the sh** out of me yesterday. After a TB breaking on me, I thought it was that at first or a spark plug that shot out of the head. Anyways, I'll let you know if I get any codes.

 

when the EPC kicks in, you will loose all throttle control, turning the car off and back on will make it work normal again. I use to get EPC all the time when I was running a forge 004 bov.

 

Ok. Well, I only have the 710N (TT version) with a stock (not 100% sure) ecu. Lately I've noticed that boost comes on extra strong sometimes even if I'm not pressing the gas very much and then it tones down by itself while keeping the same amount of throttle. Could this all have to do with the n75 valve or something, or is this normal?

 

when the epc kicks in, are you cruising, full throttle, half throttle?
as it would kick in for me when I was say making a left hand turn from a stop or a right hand turn from a stop. basically it kicked in on me when i was coming from a stop.
check your dv, make sure its not sticking. also check the hoses too and from it. checck the hoses around the wastegate, and check the hoses around the n75.

 

That's odd, I was asking myself the same thing this morning. On the way to the car wash, I could hear my car spooling the crap out of the turbo, but it was holding it, not dropping off.
Injector cleaner ftw