EPC light?

[zigman07]

The Electronic Power Control light in my 1999.5 Jetta GLS VR6 came on a day or two ago. Now it hesitates like crazy even after I've already pulled out and am trying to accelerate. Is there any common problem/malfunction that would cause the light to come on, and is there any correlation between the light and this symptom? Also, the check engine light came on, if that helps.

Thanks for your help!

Fred

[84veedub]

If you search around I think this has been covered in detail about early mk4s and the EPC light.

[bluefox280]

You need to SCAN the ECU with a VAG-COM to get the fault codes from the ECU.
We cannot diagnose a Check Engine Light (CEL) or Electronic Power Control (EPC) light until we have fault codes.

- Erik

[truegeforce]

change the MAF!!!!!!!

also are u runing a CAI and is the ASR light on as well???

let me know

[zigman07]

No, the ASR light is not on. I took it to AutoZone, and they scanned it (that engine diagnostic tool) and it says that I need a new O2 sensor and a new speed sensor. Does this make sense?

[zigman07]

I don't know if they would help, but I also have the codes he used to find that it needs an O2 sensor and speed sensor.

[bluefox280]

Quote, originally posted by zigman07 »

Does this make sense?

Do you have the EXACT code numbers from that scanning?
Those will directly tell what's wrong with the vehicle.

- Erik

[BIGNICKSGTIS420]

speed sensor. had the same problem

[tywall3]

My EPC light has been on for weeks, and my brake lights werent even going on before...now they wont turn off! even when i turn off my car theyre still on, so i have to take out the fuse. i got my vag com yesterday, and theres no port in my laptop to hook it up to...looks like im going to have to hook it up to a tower

[zigman07]

Quote, originally posted by bluefox280 »

Do you have the EXACT code numbers from that scanning? Those will directly tell what's wrong with the vehicle. - Erik

Yes I do have the exact codes.

[vr fix]

Dude its your brake light switch probally, get it at an autoparts store....been there, do scan for codes, could be something else....gl

[bluefox280]

Quote, originally posted by zigman07 »

Yes I do have the exact codes.

Excellent; post those exact numbers and we'll be able to help you out specifically.

- Erik

[blackjackT7]

I had the same problem EPC light and the CEL I do not remember the exact codes but the car was doing the same thing. I replaced the MAF and it did not change then I replaced the O2 sensor. That did not do any thing; I did spark plugs and a bunch of other things. I finally replaced the Throttle body and that took care of the hesitation but I still some times get the EPC light. I still have the CEL the EPC light only comes on under hard acceleration.


Modified by blackjackT7 at 10:47 AM 8-14-2006

[tywall3]

can advanced auto scan our cars? i thought they didnt have a vag com

[18Tdesign]

Quote, originally posted by tywall3 »

can advanced auto scan our cars? i thought they didnt have a vag com

they don't. furthermore, the codes are different.

---- tywall3-----
it sounds like you should start with the brake light switch. it is only about $12 and is an obvious fix for the brakelights not turning off.
-----------------

I would strongly recommend scanning it with VAG-COM and giving us the codes. Much more accurate than an autoparts store.

Oh, by the way, make sure the wireing harness on your MAF is plugged in. That is another simple thing to check that would potentially cause these symptoms.....It could be quite a few things, but it kind of sounds like a bad MAF.

..but get those codes.

Modified by 18Tdesign at 7:44 AM 8-15-2006

[tywall3]

thanks man...ill go get a brake light switch tomorrow....where is the maf located?

[18Tdesign]

Quote, originally posted by tywall3 »

thanks man...ill go get a brake light switch tomorrow....where is the maf located?

it's in the big plastic cylinder behind the air box. there is a wire harness plugged into it.

[84veedub]

Quote, originally posted by tywall3 »

thanks man...ill go get a brake light switch tomorrow....where is the maf located?

I just bought my brake light switch, it was $8 ,same problem.

[JIMMYJOEGG]

Quote, originally posted by tywall3 »

thanks man...ill go get a brake light switch tomorrow....where is the maf located?

I believe the switch it covered under a recall, they replaced mine for free due to a recall on the switch.....I had the same problem.

[USCGMK]

my EPC light came on, i read the DIY on how to repair the brake light switch, did that, works like a champ with no EPC light.

[84veedub]

Quote, originally posted by JIMMYJOEGG »

I believe the switch it covered under a recall, they replaced mine for free due to a recall on the switch.....I had the same problem.

I have had very little success with the dealerships around me, I just said for $8 and a few minutes of my time, I'd rather put it in.

[felkadelic]

Quote, originally posted by truegeforce »

change the MAF!!!!!!! also are u runing a CAI and is the ASR light on as well??? let me know

No -- don't just start changing parts hoping you stumble across the problem

[BIGNICKSGTIS420]

Quote, originally posted by felkadelic »

No -- don't just start changing parts hoping you stumble across the problem

what he said. we have sensors for a reason

[tywall3]

Im waiting for splisks to put my fault codes online (cause he scanned my car for me)...but I just replaced my break light switch, which i though was the problem....and my break lights are still on! ahhhhhhhhhh

[asphaltvr6]

http://forums.vwvortex.com/zerothread?id=2757562

[murf8398]

someone help me...my cel epc and asr have been on forever i have brought it to numerous places and they are stumped....i ahve changed the maf coil packs and o2 sensors, spped sensor has also been changed...this car has been driving me nuts anyone with the same problem? plus the car just has a rough idle and will stall out...help me out

[18Tdesign]

Quote, originally posted by murf8398 »

someone help me...my cel epc and asr have been on forever i have brought it to numerous places and they are stumped....i ahve changed the maf coil packs and o2 sensors, spped sensor has also been changed...this car has been driving me nuts anyone with the same problem? plus the car just has a rough idle and will stall out...help me out

scan the car with VAG-COM and report back with the codes.

[Johnnie11]

The EPC light is tied into a pressure sensor in the block. Loosen the oil filler cap, check the oil, and retighten the cap. if you don't have a real problem, the light will go out.

[hills]

the "release the oil pressure by simply removing the oil cap for a few seconds" DOES work and is a great quick fix however a good buddy of mine, who is also a tech at Scott Volkswagen, in RI, took his time to call me after my check and give me a low down.

more or less this is what he said:
- the throttle body is the most common issue when it comes to the EPC light on the FSI and TSI engines, I dont know why but Volkswagen installed these ****ty little wire sensors (6) into the throttle body to measure various things, mostly oil and gasoline vapor. the system is great but the problem is that volkswagen used cheap non plates/coated wires and they wear down and start throwing codes or false codes around 25-30k+ miles. we have a repair report from Volkswagen actually that came in over this exact subject. releasing pressure Via the oil resivoir and sometimes cleaning the throttle body [which by the way he scaned my car and the code was from the TB] will work, but only temporarily, usually once this starts happening it will happen again, and become more common. (me: by the way I did the release trick once about 150 miles ago, got my oil changed and it hasn't been a problem since). Once it starts to be at the point where you want to fix it we have better copper plated wires that we simply replace the old wires with and aren't that expensive and should only take an hour of labor, maybe 2.- --steve

hope this may help some people

[jetster1989]

My EPC light is also on. I have replaced the TB after a shop said it was 100% the TB after scaning it and spending $200 of the diagnosing it.. i am at my wits end on this car and just want to fix it. i have so much i want to do to it and have already spent way to much money on it...new motor and trans...how much are the copper wires..i am very interested if this will help that DA** light go away. thanks...

[roadsterred]

EPC refers to Electronic Power Control. It's a fly-by-wire system between your accelerator pedal and the engine's throttle valve. Your Accelerator pedal has a position sensor which communicates with the Throttle valve control module via the Engine control module.

Except for the light, did replacing the TB correct your hesitation problem? If yes, this is just a guess, you may have to erase the Fault Code to deactivate the EPC light.

[jetster1989]

EPC refers to Electronic Power Control. It's a fly-by-wire system between your accelerator pedal and the engine's throttle valve. Your Accelerator pedal has a position sensor which communicates with the Throttle valve control module via the Engine control module.

Except for the light, did replacing the TB correct your hesitation problem? If yes, this is just a guess, you may have to erase the Fault Code to deactivate the EPC light.

i drove the car around after changing the TB for about 5 days then the EPC light came on. let the car sit for a day or so. came back. started. no EPC light. half mile down the road. it came back on. i will try to have it reset and see if it comes back on. if it does, i will come back with the codes...just getiing up and tired of this car.lol.great when it runs right
just cant wait till i can do wheels and tires. drop kit. and performance up grades...first things first....get it running right...o...and get the a/c fixed lol

[taskforce51]

My EPC light came on the other day and now my car wont run. it first started out as i couldnt go above 30mph and when id hit the gas i would go nowhere. i could have made more boost riding a bike then i have when i hit the gas. then after letting it sit for a few days i got back in it and went to start it, it took a few seconds to start (not normal) the rpms went way up and then back down until the car cut off. ive talked to a few people about this and i have got so many different answers i dont even know where to start. i know one of the problems of the car starting and cutting off may be the MAF, but the EPC light has me confused. ive been told it was the crankshaft sensor??? i just need a lot of help! oh and the car is an 06 jetta gli 2.0

[mencho73]

hi my friend can you tell me what to do my epc light is on but the car run perfect
I also went to dyno my car and my boost drops from 11 to 0 @3000 4000rpm
has this have somthing to do with epc licht

[louie dodu]

"hi i have a jetta 2001 . epc and after check engine was on for few days ago. and then gone. came back again. its like this lately. i found out its something with power gauges. when i start car, indicators of power stay under 10. i drive around 10 15 mins. and at the red light i stopped. car stopped by itself. i started (barely) and this time indicator of power was at 10. after that when ever i stop . indicator stay at 10 and car never stopped by itself. so this is my theory if indicator of power stays under 10 during the car stopped means car is gonna stop any moment. but if its stay around 10 ( power gauge ) that means its okay. so what it could be? am i making up or am i right somehow ?