# Help please! Epc light stays on gas pedal not responsive



## danno151 (Aug 11, 2010)

So the other day I was getting an alignment done on my car and when I pulled onto the rack the 02 sensor wires were pulled out of the sensor and after I checked to make sure that it wasn't anything searious like gas or break lines I started my car back up and the epc light was on and the rpms shot up without even touching the gas pedal after replacing the o2 sensor the problem wasnt fixed and now when I start the car it sounds like crap and if I push the gas it doesn't rev up at all. I'm now stuck leaving my car in school trying to figure out what's wrong with it we used a scan tool and the code P2128-trottle/pedal position sensor/ switch E circuit high. Does anyone know how I could relearn the electronic throttle position or if anyone has experienced this and can help with how to fix it I would really appreciate it because I am stuck now and have no idea what I can do to fix it. I have already taken the pps out and opened it up and cleaned it out because I saw another thread saying that someone with the same problem cleaned the sensor out and it fixed his problem but It did nothing for me. Thanks for ur help in advance.


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## Scigano (Mar 10, 2011)

Could this be similar to when frayed insulation on O2-sensor wires cause them to short out?

Typically, I've only seen people say it happened to them because of worn cables for the O2-sensors touching metal, but if the OP's wires only became disconnected (but remained intact if they were able to plug them back in I assume), I don't know if the shorting situation could still occur.

Other's input?


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## danno151 (Aug 11, 2010)

Scigano said:


> Could this be similar to when frayed insulation on O2-sensor wires cause them to short out?
> 
> Typically, I've only seen people say it happened to them because of worn cables for the O2-sensors touching metal, but if the OP's wires only became disconnected (but remained intact if they were able to plug them back in I assume), I don't know if the shorting situation could still occur.
> 
> Other's input?


 When they were pulled out of the sensor, one of the wires did touch the body of the car, I replaced the o2 sensor and the epc light is still on and the problem is still there, any ideas on how I can fix it now if there was a short that caused this?


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## Scigano (Mar 10, 2011)

If you _did_ short the O2 sensor wires, I'm afraid that you'll have to replace your ECU. (or so that's what I've mostly found)

When the O2 sensor wires short out, the way the ECU is hardwired, it critically damages the pedal/throttle control components of the ECU as well. Only solution so far has been a new ECU. Hope I'm wrong .


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## danno151 (Aug 11, 2010)

Ok I hope ur wrong too if u find anything else please keep me posted thank you for ur help


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## Freddy24 (Oct 16, 2011)

Help! I have the same damn problem its just that mine randomly happened in the middle of the road! Epc light is on gas pedal not working!


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## Scigano (Mar 10, 2011)

Freddy24 said:


> Help! I have the same damn problem its just that mine randomly happened in the middle of the road! Epc light is on gas pedal not working!
> 
> 
> Sent from my iPhone using Tapatalk


Freddy24, 

When this happened to you, were you able to turn the engine off and on again, and everything was okay afterwards (barring it happening again)? I want go determine if you were able to turn the car off and on again to clear the EPC light and then continue to drive.


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## Scigano (Mar 10, 2011)

danno151 said:


> Ok I hope ur wrong too if u find anything else please keep me posted thank you for ur help


Hey Danno151:

I got this from the 1.8T FAQ and Trouble Shooting section:

O2 Sensor – Because of strict emissions these 1.8T’s are very sensitive to readings from the O2 sensors. MY 2001+ have a wideband front O2 sensor with high accuracy and a linear response. The car will adjust the fueling based on the readings from the sensor. If the sensor is over heated, exposed to lead (race gas), flooded with soot (too rich) or is just old, it can provide the car with false readings and the car will not provide the proper fueling. When the O2 sensors go bad and the ECU detects this the car will run on reserve fueling maps and will not be able to adjust for boost leaks, fuel pressure, MAF readings or any other parameter that affects fueling. To check for a bad sensor the first thing to do is run block 032 on the VAG com. If the sensors are bad, the readings will both be 0%, replace the Front O2 sensor. If the sensor is bad, it will also respond slowly, or reach a peak. Logging block 031 will show the lambda reading from the O2 sensor as well as the requested lambda from the ECU. To get air fuel ratio multiply lambda by 14.7. If the lgo shows the lambda jumping wildly when running through a gear, or perhaps it flat lines at an unreasonable level, then the O2 sensor should be replaced. It is a 50$ part. *If the o2 sensors get shorted out or the wires get pulled, they will damage the ECU, be careful with the wiring on these sensors.* *2000 and older cars do not have a wideband sensor, however they will still perform some adjustment of fueling based on the sensor.


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## Jurgy (May 17, 2004)

Scigano said:


> If you _did_ short the O2 sensor wires, I'm afraid that you'll have to replace your ECU. (or so that's what I've mostly found)
> 
> When the O2 sensor wires short out, the way the ECU is hardwired, it critically damages the pedal/throttle control components of the ECU as well. Only solution so far has been a new ECU. Hope I'm wrong .


Hate to tell you this, but this is likely what happened to you as it happened to me some years ago; I ran over a piece of plywood in the road that somehow reached up and snagged the O2 sensor; throttle went dead, then when I turned it back on revs shot up like crazy. 

Came down to replacing the ECU; used is cheaper, as long as you can figure out the immobilizer issue.


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## AmIdYfReAk (Nov 8, 2006)

Funny, i did a repair for a texer a little while ago.. then Monday it happened to me.

On the hunt for more ECU's


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## danno151 (Aug 11, 2010)

Bump should I just get a pedal position sensor or should I not even waste my money and start looking for ecu's


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## AmIdYfReAk (Nov 8, 2006)

danno151 said:


> Did u figure out the problem with your car?


 What problem? The information on the topic was clear.

If you've shorted the o/2, the ecu is done.... Simple as that.


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## Scigano (Mar 10, 2011)

The O2 sensors are wired in w/ the pedal control (which makes sense, since it all relates to air, fuel, and calculated torque) in the ECU. Shorting out the ECU doesn't fry the entire computer, but takes out a hugely integral chunk of it. That's why the car still fires up, but the throttle goes spastic. Sorry sir. 

I don't know if a Motronic electrical engineer could fix that. A new ECU is what you must find (and eliminate the immobilizer).


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## AmIdYfReAk (Nov 8, 2006)

No need to go that for for repair, as stated a above I repaired the same issue for an above texer.

There is a driver chip on the board that takes the hit, and goes out.

And adapt the immo or defeat it.


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## Freddy24 (Oct 16, 2011)

Scigano said:


> Freddy24,
> 
> When this happened to you, were you able to turn the engine off and on again, and everything was okay afterwards (barring it happening again)? I want go determine if you were able to turn the car off and on again to clear the EPC light and then continue to drive.


Nope, i reseted the car and rpms shot up crazy. Gonna check under the car tomrrow...


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## danno151 (Aug 11, 2010)

Bump Freddy any updates on ur car if u found the problem?..fixed it? I'm still stuck don't want to believe I need a new ecu


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## Chris164935 (Jan 10, 2004)

If you do not want to believe the ECM is fried from shorted O2 wires just yet, then get the car scanned by someone with VAG-Com or the dealer. EPC light code be from a number of things. Throttle body died, pedal sensor died, something stuck in the throttle body, a wire to the trottle body broke (that has happened to me randomly), etc.


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## 00B5A4 (Oct 28, 2011)

Scigano said:


> Freddy24,
> 
> When this happened to you, were you able to turn the engine off and on again, and everything was okay afterwards (barring it happening again)? I want go determine if you were able to turn the car off and on again to clear the EPC light and then continue to drive.


 this is exactly what happened to me, what does this mean?:banghead:


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## Scigano (Mar 10, 2011)

00B5A4 said:


> this is exactly what happened to me, what does this mean?:banghead:


 You could have triggered the *torque limit exceeded code*. Basically, I think it's a way of the engine protecting itself from when it detects a moment of uncomfortable lean-ness. In VAGCOM, the code listed for it is _Torque Monitor 2: Limit Exceeded_. Possible reasons, like any leak between the MAF and turbo (unmetered air) or clogged fuel filter point to having had a lean air-fuel ratio. 

This explains why it's such a Hard Limp: EPC and Traction Control lights come on and the engine begins to decelerate on it own until reaching about 1,000 RPMs and hovering there until the engine is cycled on and off. 

During this time, you will have no throttle input (to protect itself, pedal input is cut until the car is reset). 

Any of this sound familiar?


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## fish10782 (Oct 20, 2011)

I hooked my wires up wrong on the boost pressure sensor and it did the same thing. The engine would respond to throttle initially when started, but only for a split second..


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## BluishGreen1.8T (Sep 2, 2006)

Ive had this happen to me as well. O2 sensor wires touched together and fried the gas pedal circuit in the ecu throwing those exact codes. Had to get a new ecu. 

GL.


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## 00B5A4 (Oct 28, 2011)

Scigano said:


> You could have triggered the *torque limit exceeded code*. Basically, I think it's a way of the engine protecting itself from when it detects a moment of uncomfortable lean-ness. In VAGCOM, the code listed for it is _Torque Monitor 2: Limit Exceeded_. Possible reasons, like any leak between the MAF and turbo (unmetered air) or clogged fuel filter point to having had a lean air-fuel ratio.
> 
> This explains why it's such a Hard Limp: EPC and Traction Control lights come on and the engine begins to decelerate on it own until reaching about 1,000 RPMs and hovering there until the engine is cycled on and off.
> 
> ...


 
all of that is exactly what happened to me. But I've only thrown one code, and it was the maf a few days, i erased it and the code never came back, but my car still does this problem.


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## Scigano (Mar 10, 2011)

00B5A4 said:


> all of that is exactly what happened to me. But I've only thrown one code, and it was the maf a few days, i erased it and the code never came back, but my car still does this problem.


 A dying MAF can throw this code. Perhaps you should prepare for getting a new one. Can you recall the code you got? VAGCOM lists possible reasons for this code to be unmetered air between MAF and Turbo, check air temp sensor, coolant temp sensor, and fuel system (possible clogged filter). They may be one or two more I didn't recall. 

I have more than one thread on the issue, check my started threads on my profile. At first, I thought that it was an issue w/ there being existing perameters in the ECU for how much load/calculated torque the engine should produce at any given RPM, throttle position, etc and that my chipped ECU (GIAC) was exceeding those limits in certain conditions (trying to boost from very low RPM for example). 

But then I thought that all the possible reasons VAGCOM listed were either for more air than the ECU wanted or less fuel than it thought it needed. So I came to a conclusion that *torque limit exceed* = *lean running condition* (n' lean means power, so "torque limit exceeded" could make a bit of sense). 

But we're thread-jacking :facepalm:. Has the OP decided to get a new ECU?


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## penpen132 (May 21, 2011)

I know this is an old thread, but, I am having the same problem. Driving down the road and EPC light came on. No throttle at all, turned the car off, just idles. Got it scanned and got an error for my cat (have a APR TBE), 02 sensor (frayed), and Throttle Sensor. I have replaced the throttle sensor, will I need to re-adapt the throttle body to the new sensor or you think my problem is the same as everyone else?


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## dane. (Nov 16, 2007)

penpen132 said:


> I know this is an old thread, but, I am having the same problem. Driving down the road and EPC light came on. No throttle at all, turned the car off, just idles. Got it scanned and got an error for my cat (have a APR TBE), 02 sensor (frayed), and Throttle Sensor. I have replaced the throttle sensor, will I need to re-adapt the throttle body to the new sensor or you think my problem is the same as everyone else?


More than likely you will need to find yourself another ECU.


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## penpen132 (May 21, 2011)

Figures. May just fix this thing and trade it in, constantly one thing after another, such a shame though because this car is a blast to drive, especially on the curvy back roads I live on. Will post once I try the VAGCOM.


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## K.M.A.S.W. (Feb 3, 2012)

unplug your map sensor and see if that changes anything..if it does, you need a map sensor


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## dixongli (Sep 24, 2007)

penpen132 said:


> Figures. May just fix this thing and trade it in, constantly one thing after another, such a shame though because this car is a blast to drive, especially on the curvy back roads I live on. Will post once I try the VAGCOM.


I just had this problem. I had to buy a new ecu. The way you get the rpms to go up is you hit the brake.

Sent from my HTC_Amaze_4G


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## joequin (Apr 16, 2014)

*NO pedal accleration do I need a new ECU?*

These are my VAG-COM codes I own a 2003 Jetta I changed the throttle body, do not have any accleration in my pedal...HELP my car is about to find itself in the lake down the road soon Do I need a new ECU
6 Faults Found:
18047 - Accelerator Position Sensor 1/2 (G79/G185) 
P1639 - 35-00 - Implausible Signal
18039 - Accelerator Position Sensor (G79) 
P1631 - 35-00 - Signal too High
18042 - Accelerator Position Sensor 2 (G185) 
P1634 - 35-00 - Signal too High
16497 - Intake Air Temp. Sensor (G42) 
P0113 - 35-10 - Signal too High - Intermittent
17526 - Oxygen (Lambda) Sensor Heating; B1 S2 
P1118 - 35-00 - Open Circuit
17524 - Oxygen (Lambda) Sensor Heating; B1 S1 
P1116 - 35-00 - Open Circuit
Readiness: 0110 1101

ANY HELP APPRECIATED


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## dane. (Nov 16, 2007)

Firstly, did you do a TB Adaptation?

Second, physically/visually check your O2 sensors & their wiring.

If their wiring has incurred any damage you are out an ECU I'm afraid.


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