6
TT-RS/Golf R master cylinder
- Thread starter the bruce
- Start date
mikejsmith1985
Go Kart Champion
mikejsmith1985
Go Kart Champion
So looking at the brake light switch stuff a bit this morning. I have 1 pin with 12v and 3 pins with ~.009v while the car is powered on. Depressing the brake makes no change to voltage so that proves there is only one switch in play here.
With the harness unplugged the lights stay on all the time. I need to get voltage readings from the other 3 pins while the car is running both with the pedal engaged and disengaged to determine exactly what I need to mimic. The location of the pins is going to be difficult to see and access but fortunately I do know a guy with a stock MK6 So I should be able to get it figured out.
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With the harness unplugged the lights stay on all the time. I need to get voltage readings from the other 3 pins while the car is running both with the pedal engaged and disengaged to determine exactly what I need to mimic. The location of the pins is going to be difficult to see and access but fortunately I do know a guy with a stock MK6 So I should be able to get it figured out.
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mikejsmith1985
Go Kart Champion
Found some wiring diagrams hopefully this will save me from having to disassemble my friends car in the 20* weather this afternoon.
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mikejsmith1985
Go Kart Champion
[emoji41]
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[emoji41]
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Damn! The battery terminal ends connected make the battery look even smaller!
mikejsmith1985
Go Kart Champion
It's a tiny battery!
So I had to work all day yesterday. I'm going to play with the wiring today and see if I can get a functional brake light switch.
Friday night I got a 2nd person to help with the VCDS bleeding and I couldn't do it because without the brake light switch it can't detect pedal position and won't move beyond the first step...
I did use a magnet and bench test the GTI sensor to confirm what I need to replicate.
Pin 4 is constant 12v
Pin 2 is ground
Pin 3 receives power from pin4 when pedal is not engaged and lights are off.
Pin 1 receives power from pin4 when pedal is engaged and lights are on.
Next steps?
The brake pressure sensor is the same 4 pin connector but actually only uses 3 pins. So I need to determine which pin gets constant power and which pin gets activated when the pedal is engaged. Ground pin may not be used or I may have to ground it to the MC.
Next option is to also test the 6 pin connector which only uses 5 pins on the Touareg brake switch and I may need to de pin the factor connector and switch to the Touareg connector.
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You could try the switch from the previous generation, extend the cables into the cabin. 9C0945511A
mikejsmith1985
Go Kart Champion
Well I had a friend come over and he talked me into removing the switch from the servo to get a part # so we could find a schematic for it as our voltage tests weren't really telling us anything we expected to find. And it doesn't really come out and now I can't get the damn locking but on and I've boogered up the sensor housing around the locking mechanism if I can manage to get it back on it'll be functional but I'm a bit outdone with myself. I told him it was a terrible idea to try and remove it lol. And it has to be in there to seal the booster so no vacuum leaks.
After a short brake I got the sensor back in [emoji106]
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What does the sensor look like from the inside, is it a push rod?Well I had a friend come over and he talked me into removing the switch from the servo to get a part # so we could find a schematic for it as our voltage tests weren't really telling us anything we expected to find. And it doesn't really come out and now I can't get the damn locking but on and I've boogered up the sensor housing around the locking mechanism if I can manage to get it back on it'll be functional but I'm a bit outdone with myself. I told him it was a terrible idea to try and remove it lol. And it has to be in there to seal the booster so no vacuum leaks.
After a short brake I got the sensor back in [emoji106]
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mikejsmith1985
Go Kart Champion
I couldn't get the damn thing out to tell... I think it's this switch though.
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mikejsmith1985
Go Kart Champion
I interpret this to mean:
Pin 3 = constant 12
Pin 2 = switched power
Pin 4 = switched power
Pin 1 or 6 = can be my ground
Pin 5 = no wire present
If this logic is right this picture shows how I need to re pin the GTI harness.
The tool I used to de pin my coil pack terminal when I mucked it up has a pair of prongs that fit in these connectors but they don't seem to be disengaging the pins I can of course splice these but I'd prefer not to cut my harness if possible.
Prongs that fit are in 12o clock position.
**EDIT** I forgot about the secondary lock typically a purple clip inside the connector. I will revisit this tonight I hope!
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mikejsmith1985
Go Kart Champion
I now have a functional brake light switch pinned exactly as my previous post suggests. I used pin one as ground in my install.
I also responded the reservoir cap so I could use the Touareg cap.
Now that I'm not using the brake pressure sensor I wish I had removed and capped it. Perhaps I'll do it next time I flush the fluid. The whole system is in and "functional" although I do need to get the air out of the system still. I REALLY can't wait to get this back on the road.
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I also responded the reservoir cap so I could use the Touareg cap.
Now that I'm not using the brake pressure sensor I wish I had removed and capped it. Perhaps I'll do it next time I flush the fluid. The whole system is in and "functional" although I do need to get the air out of the system still. I REALLY can't wait to get this back on the road.
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mikejsmith1985
Go Kart Champion
Ha ha! It's taken far too long!!! I'll be working up a "cliffs notes" type of DIY post for this. I don't want to be the guy to say "if you want to do it figure it out" but I will say that if your considering doing this and you need an explicit step by step to feel comfortable with it then just do the TTRS MC swap. I obviously don't know how I'm going to like the finished product but it's going to have to be pretty disappointing for me to go back at this point. But it wasn't a budget friendly mod by the time you take into account my $250 battery, $80 for the booster and MC, $120 for my portable jump pack in case my battery turns out not to work as well as I hope, and all the nickel and dime stuff to get the right components for the brake lines, the tools to re-pin the connectors if you don't already have it etc. Not going with a lithium battery can save just under $300, plus you don't have to go crazy with the mounting solution like I did... but I feel like I finally have a reason to pop my hood at a car show lol
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