[gazaflash]

Well…! It’s broken again!
Had a fault on the EPB system
Tried disconnecting battery and waiting a few minutes, before reconnecting battery. Same problem! EPB fault, red flashing on dash. Cannot release EPB to drive away. Had to get a flatbed to take it home.
next problem was to drag it from driveway into garage to work on it!
Used crazy carpets and wheel dollies to pull it in the garage.
Plugged in VCDS and this was the codes in module 53.
I am going to try and remove the EPB electric motors and manual turn the screw to open the brake shoes. Anyone done this before?
I can’t do a basic setting so if I can get the drive mechanism to retract. I’ll start from scratch with the basic setting and see if the module wants to play…!
Anyone have any other suggestions?

 

[SaVAGeSoot]

Why are you attempting to clear codes by disconnecting the battery if you have VCDS?

 

[gazaflash]

Why are you attempting to clear codes by disconnecting the battery if you have VCDS?

I never had my VCDS when the EPB fault occurred. I thought I would try and disconnect battery to see if that did anything... which it didn't!
I have the car in the garage now so now I'm checking with VCDS, hence the print out.
I tried to function the motors so the brakes would release but it came up with an error 7F 7F 7F?

 

[gazaflash]

Oh yeah...! I said previously that maybe I could remove the EPB motors from the housing but it's bolted from the inside. No can do!
If I can drive the motors electrically, so it opens the brakes then I can remove everything and start from scratch with basic setting and grind in procedure... etc...
I am getting all the codes from the module so I think the module is OK. The errors do not say that one of the motors are not working, so I'm ruling that out for now too.

 

[SaVAGeSoot]

Can you clear the codes under that module?
Can you open and close the caliper under output tests?

 

[gazaflash]

No, can't clear the codes under the module.
Won't allow me to open or close the caliber.
there is no current draw, air gap is 1.89 and 2.09 on the left hand side. Min should be 1.9. Possibly suspect air gap is not in spec which maybe why its stopped working?? Just surmising.
Why is this EPB so complicated? None of the other VW cars have this particular setup except for the Phaeton!

 

[SaVAGeSoot]

Because it's a Porsche system.
Use the adjuster to back off the shoes and remove the rotor.
Then remove the shoes.
Then you can access the mounting bolts.

 

[gazaflash]

Because it's a Porsche system.
Use the adjuster to back off the shoes and remove the rotor.
Then remove the shoes.
Then you can access the mounting bolts.

Can't do. EPB has locked the rear brakes, so I can't turn the discs to get to the right position to manually adjust the adjuster through the little access hole. There is no other hole or aperture on the backing plate either.
I wonder if I can just apply 12 volts to the EPB motors and unscrew the mechanism? then I can get access.

 

[SaVAGeSoot]

What other options are there under output tests? Did you try them all? I thought there was one with PWM signal or something too.... can't remember and it's been a while since I poked around in there.

 

[gazaflash]

I tried that too! Pulse width, power, etc …!
I am at a loss!

 

[SaVAGeSoot]

The drivetrain should be able to overpower the parking brake. I'd try driving off to see if they let go.

 

[gazaflash]

Good thinking…! But I’ve tried that. No movement it would not budge. Just complaints from the backing plates been put under some strain. Tried it in both directions. That’s with the foot to the floor on the accelerator and it just takes the power away! Saying that… I could have switched off the traction control. Oh well, it’s at home in the garage. Hopefully it will dry out a bit. Snow and ice was melting all over it, dropping down me neck and in ears, when working on it earlier

I will have a look at all the connections tomorrow morn.
I’m two minds, wether I just apply 12vdc to the motor pin outs. The manual mentions when installing new motors, there is an initial installation function prior to doing a basic setting. But I don’t want to adjust the motors separately, then have an issue when plugging everything back n again.
Stay tuned… I guess!

 

[SaVAGeSoot]

Well, I don't see how both motors would fail at the same time. I don't see how you'll get around having to adapt or redo settings after fixing whatever has failed.

It would be worth trying to apply power without the nannies on and maybe even in offroad mode.

 

[Brendanm]

You can just apply power to the motor to back it off. I did it with mine when I had a park brake motor fail. Tapped with a hammer and applied power until it backed off.

 

[SaVAGeSoot]

@Brendanm
Does it take straight voltage across pins 1 & 4 or is it PWM driven?

 

[SaVAGeSoot]

@gazaflash
IF both sides are locked, I'd suspect that your EPB controller has pooped itself as if it was one of the motors, the other should still react, etc.... at least in my logic.

 

[gazaflash]

Agreed boys! About 3 years ago I did have a left motor burn out and VCDS said that motor was goosed or some words to that effect.

Today, I will apply power to the two pins on each motor and see what if does! There are 4 pins, two for the motor and I gues the other two for the sensing circuit.

If that doesn’t work, I’ll cut both hubs off and fit brake cables and lever..!! 🤣🤣🤣🤣

 

[gazaflash]

This is the wiring diagram but doesn’t say anything about pulse width modulation or anywhere else in the manual for that matter

 

[SaVAGeSoot]

Yes, 1&4 for motor and 2&3 for sensor from what I recall... and ignore the garbage about PWM above from me.... I wasn't thinking.

 

[Brendanm]

@Brendanm
Does it take straight voltage across pins 1 & 4 or is it PWM driven?

Straight voltage.