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Discussion Starter · #1 · (Edited)
I was driving through a construction zone and ran over something and broke the rear oxygen sensor wires again.
But this time I think the wire shorted to ground.
I have the p2128 and I had the p2133 codes but the 2133 code went away when I cleared it.

Did a lot of searching and this is what I found.
This appears to be all too common.
You're driving along and run over a stick, plywood, tumbleweed or some other solid road garbage, your oxygen sensor wire gets severed (they usually don't say if its the front or rear), a wire shorts to ground, the EPC light comes on, you get p2133 and/or p2128 car will idle and only drive 15 mph.
And you need a new computer.

I pulled the electronic gas pedal thing apart and its as clean as a watch in there. I did this before I found the repeating story above.

Do you believe my diagnoses is correct, or did I miss anything?
Looks like I can pickup a used ECU for about $70 or a stage whatever aftermarket ECU for $300.

I wouldn't be opposed to the aftermarket ECU if it made the car faster and didn't hurt fuel mileage.

Yes I repaired the broken wire, now I just need to find a way to keep it from happening again. Since this is the second time that wire has been severed, last time I just got lucky and some how the wires didn't short to the vehicle exhaust and ruin the ECU and so I fixed them and tucked them back up under there kind of how I thought they did from the factory.
If I had any idea this could happen I would have reran the wire inside outdoor rated flex conduit and added hangers and conduit clamps or some extreme level of over kill to that effect.

At least it looks like I wont have to go to the dealer ship for this one.

EDIT: I examined some of the severed wires I cut out to for the repair. It appears that only the black (likely the power wire) had exposed conductor that could have shorted out against the exhaust pipe.
 

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http://wiki.ross-tech.com/wiki/index.php/18560/P2128

http://wiki.ross-tech.com/wiki/index.php/18565/P2133

Based upon the above links and your research; you have narrowed down the possibilities. Now it just depends on how you approach the repair process you can progressively replace parts and test after each part is changed and hopefully, through a process of elimination, you will find the problem. What kind of scan tool; do you have access to? For testing each component with output tests, live data and possibly doing the coding of a new or used ecu, you really need VCDS from Ross Tech. When it comes to the ecu coding; you could have someone repair your original ecu or transfer the coding to another ecu; thus, eliminate the need for VCDS, to do the coding. I would contact Ian at reflect tuning.com and see what your repair options are. I don't know; what coding options, normal auto parts stores would have with this type of thing (if you purchased a new ecu through someone like autozone). When it comes to coding issues there are two routes; it seems to go all the way, get VCDS, Vag Tacho for pulling the secret key code or ship out the repair and/or coding to a specialized repair shop like reflect tuning, thus plug and play, repair complete. A third option; is take it to a Volkswagen dealer and spend tons of dough for them to do everything. My personal approach; would be to replace the parts progressively and test, confirm things as you go along, until you find the problem. Keep in mind I have access to VCDS, vagtacho, the secret key code and everything needed to complete the repair. Think about your resources; how far you want to go with doing the ecu coding/repairs yourself, how much money you want to spend and how quickly, you want the repairs completed.... then, we will go from there.
 

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Discussion Starter · #3 ·
My scan tool is just a $40 code reader and code clearing tool.
Its about as simple as you can get.
The nearest advanced diagnostic computers are at the dealerships, about 100 miles away going south and the other one 100 miles east.

I don't do ECUs, I try to avoid them. I would need it to be plug and play by the time I got it.

Alright, so it looks like I am taking bids and references now.
I can pull the computer and have it sent off to get repaired.

If someone has the advanced ECU tuning setup can they plug into the test station and tell if the computer really is the problem?
I think I read that the shorted O2 wire burns out one of the solid state drivers on the ECU. There should be a test for that right?
 

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I have taken a ecu apart to inspect it but I haven't done any board level repairs on one. I would think; that a ecu tech's repair/rework station, would have all the adapters and testing equipment needed, to diagnose the problems. I don't recommend this but check out this video, to get a sense of what the board looks like and what type of onboard components can fail.

https://www.youtube.com/watch?v=vYsdw_gKEgA

This type of work; is best left to the professionals, imho.

When it comes to diagnostics; you would need to do a step by step troubleshooting process. Based upon the links and your own research, it seems that the testing and replacement process would be:

1. 02 sensors

2. accelerator pedal

3. ecu

I would test with live data, output tests and scan for trouble codes, after each part would be worked with. If you look in the manual; for each of the parts in the list, there are specific testing, a diagnostic flowchart to go through. It takes time, effort to test each component and figure out what the problem is, following the factory manual procedures. The other option; is to throw parts at the problem and see if it works. Having a scanner with live data and output testing capability, would make this much easier (Ross Tech VCDS; being the most complete and affordable solution).

Check out the manual; for testing procedures and start working on the list in a process of elimination:

Volkswagen Workshop Manuals

There are probably many places; that can repair a ecu; I would contact ian @ reflect tuning and see what options he has to offer. I had him; zero out my speedo cluster, he was quick, did quality work and was very affordable.

Reflect Tuning :: CONTACT
 

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Discussion Starter · #5 ·
The front oxygen sensor is a month old. The car ran fine with no rear oxygen sensor for who knows how long afew months ago.
I put an new front sensor on when it was barely running last month and kept the old one. I would have tossed the old oxygen sensor but kept it because changing the oxygen sensor made absolutely no difference, telling me it likely was not the problem.
I can try switching back to the old oxygen sensor.

I can pull the pedal assembly again and put the multi meter on it this time.
Any one know what the values should be?
It seems from the other posts the pedal usually isn't the problem unless some junk works its way into the housing.

Since I experienced almost word for word the exact same thing as what happened to the others who had to replace the ECU I am thinking it was that.

I would like for it to be the pedal, because I could go get one from the junk yard a mile away for $5. I am very sure I wont be that lucky.
 
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