2010 New Beetle . NEW ABS (MK60) shows the Brake sw. F on all the time. NOT a switch problem

Paul Manager New Jersey Posted   Latest  
Unsolved
Electrical
Programming
2010 Volkswagen Beetle Cabrio 2.5L (BPR) 6-spd
Module Thinks The Brake Pedal Is On All The Time

Hello, I'm trying to write this though tears and an alcoholic haze. Please bear with me. This Beetle ( VIN 3VWRG3ALXAM006235) got a new module due to a persistent right front wheel speed sensor circuit fault. That problem is solved. It got a NEW (from Germany) MK60 module part # 1C0 907 379Q. The coding was pulled from the original module. Coding: 0019978. We had trouble performing basic setting 066 for the brake pressure switch. We found that the data for the Brake pedal switch shows “activated” all the time. I know there are a lot of problems with the Brake switch F historically. 

Because the ABS thinks that the brake pedal is on it would not let me run basic setting 066 for the brake pressure sensor G201. This would cause the Traction control light to be on al the time with code 01435 - No or incorrect basic settings/adaption. The brake pressure sensor is working perfectly. 0.28 bar off the pedal, scaling up from there with pedal pressure.

Just for the record, the brake light circuit from Fuse 13, through the normally open switch, will send 12v (with the pedal pressed) to pin 41 red/blk. I can light a bulb on that wire

This is the important part: If I cut the wire from the brake pedal switch F (pin 41 for anyone brave enough to dive that deep), the data still says “activated” for the pedal switch. So at this point I checked for voltage on the MODULE SIDE of the cut and had 12v with a meter. If I GROUND the wire on the module side, the data changes from “activated” to “released”. If I run basic settings 066 for G201, it completes. Traction control light is now out. I put the wire bake together. the data says my foots on the pedal all the time. Put some miles on it. Activate ABS on snow and gravel. ABS engages. No codes EXCEPT: 00526 Brake pedal switch implausible. I can clear this and it won't come back right away. After a little driving it will. I know that it is a thing with some A/T VW's that this code will set if you don't step on the brake before reading codes, but regardless of stepping on the pedal or not the code won't come back immediately. Only after driving.

So this is where I'm at: I've got an ABS module that wants to see a ground on the brake switch input when the circuit is designed to apply 12v with the pedal pressed. The circuit is designed to send 12v. I can't find any example of a VW brake switch input to the ABS that goes to ground. The “very tired of this car” part of me wants to let it go ('cuz, “hey boss the light is out”), but I'm concerned that the traction control or stability won't work properly if the module believes that my foot is on the pedal al the time.

Thank you for taking the time even just to read this. If anyone has some insight I'd appreciate it. I'm thinking that I either have incorrect coding (although others and myself have checked it several times), or I have a bad module ( please lord let that not be the case, as it takes a month to get a new one) or , due to some calamity in the past, the time line that I currently inhabit operates on different electrical principles than I'm familiar with. ;)

Anyway thanks again.

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Larry Owner/Technician
California
Larry
 

We have recently been down this road on an A4, right down to the cutting of the wire. Brake light switch is also directly wired to ECM after the splice which is where the 12v comes from. I suspect your measure block that says brake switch is “activated” is the “From CAN” block. Ours was the result of relays and a dme full of water due to plugged cowl drains.

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Marlon Owner/Technician
California
Marlon
 

If you have not done so, please check to make sure correct stop lamp bulbs are installed. I had one set the same fault due to incorrect LED light bulbs were installed.

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Paul Manager
New Jersey
Paul
 

Okay, okay, okay…first, thank you. I don't understand it, but if I disconnect the DME (which on the beetle is under the left plenum cover) the brake switch PID will read “released”. As soon as you step on the brake it will read “activated" . It won't change back to “released” when I let go the pedal, but perhaps it doesn't need to. I don't understand how a logic malfunction in another module…

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Larry Owner/Technician
California
Larry
 

If the label file in vcds doesnt describe the measuring block, the only further resource to figure that out would be in odis, but not sure if it does. I double checked catalog by vin and your module # does cross to the most current number, so there's that at least. I very (very) much doubt your original fault is due to the dme issue, and at the same time seems odd to have two such weird…

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Paul Manager
New Jersey
Paul
 

Very sorry to take so long to reply. It's good to be busy. The customer ended up needing the car back. He's actually been very understanding of the situation. I did verify the coding on the DME. It was correct. I wasn't able to do any further testing. I did notice that In the ECM measuring blocks: Group 066-02 is labeled Brake switch/ clutch switch shows … that changes to … with…

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Semaka Diagnostician
Uganda
Semaka
 

Hello friend, i think you need to replace the module.

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Greg Diagnostician
Wisconsin
Greg
 

Paul, I hade a Volkswagen with a brake pedal switch issue and the brake bulbs were causing the issue, I don‘t know why, but I read about it when I was working on that car, and it fixed the issue.

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Stephen Technician
Oregon
Stephen
 

Hi Paul I feel your pain on this VW and I empathize. Just an FYI on the mk60 controller. Module masters in Idaho rebuilds those for about $250.00 and gives a 5yr unlimited mileage warranty for future reference. They test it first before it goes to repair bench. I sent them a module for repair once that was some random code can't remember exactly what it was and upon testing they found nothing…

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Paul Manager
New Jersey
Paul
 

Thanks Stephen, it's always good to have more resources for module repairs. Especially these days with parts getting harder to get. The car was taken back by the customer. It will likely return as they are regular customers and hope to poke a stick at it in the future. See my reply to Larry in this thread as to where we left off with the car. Thanks again.

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