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      03-26-2012, 09:10 PM   #25

Drives: AW 1M
Join Date: Oct 2010
Location: Wash, DC

iTrader: (0)

New (and Hopeful) Info on Corner Brake Control

OK, I have delved into this further and learned more about the CBC (corner brake control) system and it suggests that it might be possible to disable it without disabling the ABS.

First, a far more detailed description of how CBC operates out of BMW literature -- not specific to the 1M -- on Dynamic Stability Control (DSC).

"CBC can occur if the vehicle is cornering and ABS regulation is not taking place.

If the [DSC] control unit detects transverse acceleration in excess of 0.6g and the brakes are applied, CBC prevents a build up in brake pressure to the inside rear wheel. This prevents the vehicle from entering into an unstable situation that can lead to Oversteer.

The DSC [control unit] accomplishes this by closing the Inlet Valve, thus not allowing brake pressure to increase at the rear caliper.

The difference in braking force between the two rear wheels creates a yaw force that opposes the oversteer and allows the vehicle to handle neutrally."

I also learned that there is a small "transverse acceleration sensor" -- likely underneath the carpet below the drivers seat -- that is connected to the DSC control module that "produces a linear voltage signal for the lateral acceleration (G-force) that ranges from 0.5 to 4.5 volts. The DSC control module uses this input to determine the side forces acting on the vehicle for DSC regulation."

I'm no engineer, but this suggests to me that it may be possible to disable the CBC either by pulling certain of the fuses for the DSC control module or by "tricking" the transverse acceleration sensor so it never sees voltage that would indicate 0.6g.

Any thoughts about this would be greatly appreciated!


Last edited by MDORPHN; 03-26-2012 at 11:07 PM.