How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask RAFALEE Your Own Question

RAFALEE
RAFALEE, VW Technician
Category: VW
Satisfied Customers: 5
Experience:  VW MASTER TECH. ASE MASTER TECH. SPECIALIZING IN EMMISION & ENGINE MANAGEMENT, BODY, CHASIS, SUSPEN.
Type Your VW Question Here...
RAFALEE is online now
A new question is answered every 9 seconds

Jetta: epc light..keeps coming..it will go in to limp mood..100 miles

Customer Question

the epc light on my jetta keeps coming on what does that mean. than it will go in to limp mood. If i shut down the car and reset it the light turns off but will come back on about every 100 miles. I just put a brand new battery and spark plugs in. please tell me what this light means. I do not have a owners manual.
Submitted: 5 years ago.
Category: VW
Expert:  RAFALEE replied 5 years ago.

Hi, EPC stands for Electronic Power Control. this means that your vehicle has a fly-bywire system, whish means that there's No accelerator cable and the throtle body is controled by the ECM (Engine Control Module). The Accelerator pedal (or gas pedal) it's just a sensor, so no mater what your input is on the pedal the ECM actuates the throtle how ever it wants. scary hu!!!, but have no fear, the Accelerator Pedal Module hoses two TPS sensors(Throttle Position Sensors), G79 & G185, this two produce an increasing voltage as you press on the gas pedal, but at diferrent rates for safety, the Throttle Body Control Module J338 (throttle body) also has two sensor G-187 and G-188, aswell as Throttle Drive Motor G186, G-187 and G-188 the output voltages mirror each other for safety reasons. back to your epc light, when you say reset it, do you actually clear the fault codes with a scanner, or you just cycle the ignition switch? either way if a fault for the brake light switch is present, this means most likely your problem is the brake light switch, some cases that brake light switch does not trigger a fault for still malfunctions and triggers an epc related code, i would replace the brake light switch, clear faults and test drive the car. so if you have anymore questions or if you can provide me with more info on the fault code numbers and descriptions, and if your vehicle is manual or automatic, please do, thanks...

Customer: replied 5 years ago.
manual, cycle ignition switch to clear fault,taken in to mechanic shop cant find codes
Expert:  RAFALEE replied 5 years ago.
ok, if your epc light comes on there will be a fault code stored in the ECM, any generic scan tool will give a pcode(a fault code with a P on the bigining), cycling the key does not clear faults it only resets it self until the fault returns, is this a manual or automatic?
Customer: replied 5 years ago.
does brake light swich over ride throttle sensors
Customer: replied 5 years ago.
manual
Expert:  RAFALEE replied 5 years ago.
No it does not, what happens is that the ECM sees an incorrect signal from the brake light switch, for example it sees your pressing on the gas an at the same time your pressing on the brake, and it will get confused, or if you have a fault with a pedal sensor or a throttle sensor, have you had your brake light switch replaced? can you please accept i will continue to help you ,thanks
RAFALEE, VW Technician
Category: VW
Satisfied Customers: 5
Experience: VW MASTER TECH. ASE MASTER TECH. SPECIALIZING IN EMMISION & ENGINE MANAGEMENT, BODY, CHASIS, SUSPEN.
RAFALEE and 8 other VW Specialists are ready to help you
Customer: replied 5 years ago.
no havent replaced
Expert:  RAFALEE replied 5 years ago.

i would replace tha brake light switch first, it's the easiest and reletively inexpensive, if you could come up with fault codes it would be much help full, i don't understand why the repair shop say there were no faults, usually when an epc light trigers it stores a fault in the ECM, since it's part of the ECM, they aded another light ( the EPC light) because the Check Engine Light is more emmision related isues only, so in order to alert you of an Electrinic Power Control fault they aded a light, by the way, thanks for accepting.

Customer: replied 5 years ago.
thanks ill try that because your the only one that could tell me what epc was i wish i could find a progam for lap top like at work to read my car
Expert:  RAFALEE replied 5 years ago.
TRY ROSS-TECH.COM

JustAnswer in the News:

 
 
 
Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.
 
 
 

What Customers are Saying:

 
 
 
  • I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry. Stephanie P Elm City, NC
< Last | Next >
  • I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry. Stephanie P Elm City, NC
  • used your service this weekend with "Trecers" help. thank you ,thank you, thank you. replaced an A/C fan motor. Local Auto Zone had part. $15.00 "tracer" fee and $40.00 for parts, I saved several hundreds of dollers at a shop. i will recommend you and use you in the future. David L. Richmond, TX
  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil Marysville, CA
  • Lurch. Thank you very much. I had real doubts about this website but your promptness of response, quick followup and to the point answer with picture was incredible. Charles Walnut Creek, CA
  • As a single woman, I really appreciate an excellent and affordable opinion.
    Thank you Geordie, I will not hesitate to contact justanswer in the future!
    Sue Charleston, WV
  • Another great insight to what may be the problem. I will have my mechanic take a look at it tomorrow. Thanks again, Frank...you do indeed know your stuff. Jim Castleberry, FL
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C. Freshfield, Liverpool, UK
 
 
 

Meet The Experts:

 
 
 
  • vwnewton's Avatar

    vwnewton

    VW Owner,ASE Master and L1 Advanced

    Satisfied Customers:

    307
    25 years of VW obsession turned into a job, last 15 years as a VW Tech.
< Last | Next >
  • http://ww2.justanswer.com/uploads/vwnewton/2008-12-27_221405_JA_avatar.jpg vwnewton's Avatar

    vwnewton

    VW Owner,ASE Master and L1 Advanced

    Satisfied Customers:

    307
    25 years of VW obsession turned into a job, last 15 years as a VW Tech.
  • http://ww2.justanswer.com/uploads/audidoc/2008-12-23_175252_headshot.jpg VWDoc's Avatar

    VWDoc

    Independent VW Shop owner

    Satisfied Customers:

    1713
    20 years of experience working with VW's. Independent European shop owner and technician.
  • http://ww2.justanswer.com/uploads/35/350matt/2012-6-7_182356_matsavatr.64x64.jpg Matt's Avatar

    Matt

    Engineer

    Satisfied Customers:

    506
    Mechanical Engineer with 20 years experience in the auto industry, 8 yrs in formula 1 engine testing
  • http://ww2.justanswer.com/uploads/CA/carbezerk/2011-3-13_103612_SAM0048.64x64.JPG Martin's Avatar

    Martin

    auto electrical

    Satisfied Customers:

    475
    South African Trade Diploma in Auto Electrical
  • http://ww2.justanswer.com/uploads/terocoga/2009-08-17_050126_015.JPG RobJackson's Avatar

    RobJackson

    VW Mechanic

    Satisfied Customers:

    416
    Started working in VW/Audi dealership in 1999. 2009 Registered and Certified VW Tech. ASE Master
  • http://ww2.justanswer.com/uploads/TI/tim37857/2011-10-28_23053_S6301814.64x64.JPG Tim's Auto Repair's Avatar

    Tim's Auto Repair

    mechanic

    Satisfied Customers:

    397
    Have owned a repair shop for 25 yrs.
  • http://ww2.justanswer.com/uploads/RO/rodcuda/2011-7-25_224114_Donhoff1.64x64.JPG Neal's Avatar

    Neal

    VW Mechanic

    Satisfied Customers:

    391
    Shop owner and experienced in most brands.