EVBP (Electronic Variable brake Proportioning) mal function (Rear Lockup)

[schulmann]

My rear wheels lock up in race condition or emergency braking ... meaning when I suddenly apply the brake pedal rear wheels lockup.
They lock up very early in the process and there is no pressure in the front no matter how hard I brake.
Then if I lift my feet for half second and apply the brakes again every thing is back to normal.



On the street there is no problem, pedals feel strong, ABS works properly, front wheels ABS gets engaged fine, even when I do "sport" braking everything is ok.


- Pads are ok
- There is no air in the system (But who knows)
- Differential seems to be working properly (Can diffential trigger such issue).
- Alignment and rake angle have been verified

The EVBP function is not very well document.

A guy smashed his competition coup 2yrs ago under similar conditions. No brake, no pressure in the front ... unfortunately the guy can't retest his car since it was totaled.


Any expert on this EVBP system ?

[MoparBoyy]

Thats a odd one, but i'd start by saying to fully bleed the system (including bleeding the abs pump) which needs to be done with a scan tool. verify that there is no air in the system.

[JonB ~ PartsRack]

SCARY !!!

THE YEAR MATTERS, dunno how to answer fully without more data:

You say it has ABS, so 2001-2010?


Stock Brakes: calipers, lines, etc. Stock? Stock sized wheels? Weird-wheel sizes can affect ABS tone rings.

May be the ABS Module, but NO ABS light? Or even the stock prop valve?

[venomous08]

SCARY !!!

THE YEAR MATTERS, dunno how to answer fully without more data:

You say it has ABS, so 2001-2010?


Stock Brakes: calipers, lines, etc. Stock? Stock sized wheels? Weird-wheel sizes can affect ABS tone rings.

May be the ABS Module, but NO ABS light? Or even the stock prop valve?

Jon from his previous posts sounds like Gen3-4 setup.

[XSnake]

Check the rear ABS wires

[venomous08]

Check the rear ABS wires


That and see if the tone pickups are in place still. I'm kinda left scratching my head on this one. Only a few things it could be.