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gomi_otaku, VW Technician
Category: VW
Satisfied Customers: 3448
Experience:  VW FastTrack '00-'01, VW Academy Chicago and Seattle '00-present, VW Certified
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I have a 2001 VW Beetle and the EPC light keeps coming on and

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I have a 2001 VW Beetle and the EPC light keeps coming on and I lose power, then if I shut it off and restart it,,,it revs to +5000 rpms and I have to shut it off again. Sometimes it resets itself and is OK for a while. The error code indicates the TPS...could static buildup cause electrical interference with the computer/sensors and would a static strip help?
More likely you have a problem at your throttle body. I recommend taking it off and cleaning it thoroughly, clearing the faults, and disconnecting the battery and holding the cables touching for about 10-20 seconds to reset the modules.
Customer: replied 7 years ago.
Holding what cable to where?
Customer: replied 7 years ago.
Mind if I have my mechanic try this before payment is sent? If it works, I will happily send double what I agreed to.
Customer: replied 7 years ago.
My mechanic followed your instructions to the letter and got absolutely no difference in the way it is acting. He asked me to tell you that both the throttle body as well as the sensor on the gas pedal are electrical sensor modules, in case you were unaware that the '01 was different fron the '00. Any further suggesions?
Yes, I know, I am a VW dealership mechanic. I wouldn't have replaced the pedal assembly, we have almost NEVER seen those fail. It sounds like your down to running a wiring overlay harness, at least temporarily to test the system.
Customer: replied 7 years ago.
Is that wiring overlay harness available only from a dealership and how costly is it to perform? Is it something a good "backyard" mechanic can do? Sorry to delay this...but we are grabbing at straws over this. It is very frustrating because I only recently purchased the car from a usd car dealership and they are trying their best to repair it, but the error codes are giving us fits. Again...if you can assist us in finding a solution, I will gladly double or triple the originally agreed price to pay you.

I don't mean replacing the whole body harness, I mean just running a set of replacement wires to the throttle body. At the dealership we have a selection of wire ends that we can replace into the electrical connectors and just splice in the length of bulk wire that is needed. That way the original harness is still intact and can be reinstalled if the overlay does not have any effect.

Customer: replied 7 years ago.
The codes that are showing up are for the Throttle Position Activator which is on the side of the throttle body. Can that be replaced or do you need the whole throttle body? Or is there some other method to repair this. The error codes for the pedal can now be cleared but the Activator code will not clear.
Customer: replied 7 years ago.
My mechanic also tells me that after shutting the car off and restarting, the EPC codes for the accelerator comes right back...even though they will clear...the error code numbers are : PO638 Throttle Activator Bank 1 and the pedal codes are PO121 and PO1221. Code PO 638 will not clear. Could the TPA code be what is causing the pedal codes to pop up and cause all the problems with power loss, high revs and/or surging?
Yes, those are going to definitely be related. It could be that you have a problem with the wiring between the pedal assembly and the throttle body- since this is "throttle by wire" you don't have an accelerator cable anymore, it depends on the pedal position to dicate the throttle opening. There are two circuits, that cross reference each other- one goes progressively upward, while the other goes progressively downward. If one circuit fails it takes the input for the other circuit (redundant inputs)
Customer: replied 7 years ago.
I will see what he can do...but is this normally a dealership issue or could it be done by a mechanic who thinks he can trace the wiring and test it out? Also....since none of this has worked thus you have any objection if I ask anoyher "expert" and see if he can offer anything more? I will retain your info for reference and as indicated, will pay you when resolution happens if your advice lef to the solution. Thank you for your advice so far and I may very well come back to you for more before I send your money.

Yes- you can post up another question, or if you want I can opt out on this one and another expert may post up. It's more likely to get a response with an additional thread as people don't like to step on a question that already has an answer


Customer: replied 7 years ago.
I noticed today that a PayPal payment of $15.00 was taken from my account...I am assuming it was for you. No problem with that. Thank you your fact my mechanic, by using a Throttle Box from a VW Golf they had, fixed the problem,,,it was the throttle box all the time. So...even though your advice was slightly led to a thanks again. Hope this helps you in future.

Thanks for the update- the throttle body was what was setting the fault, cleaning it and resetting the faults will usually clear it out.

The $15 is simply a transfer to this site, we as techs don't get paid unless you are satisfied and hit the "accept" button on the answer.

gomi_otaku and 3 other VW Specialists are ready to help you
Customer: replied 7 years ago.
Done....but cleaning it did nt fix had to be replaced...but it is working fine now....thanks and good luck in future