Electronic Brake Force Distribution on the car?

 

I believe its part of the stability control

 

Yes.

2008 Chevrolet Cobalt SS Coupe Full Test
listed under safety features.

4-wheel disc antilock brake system with Electronic Brake Force Distribution
Designed to help drivers maintain steering control by reducing wheel lockup during hard braking on most slippery or dry surfaces. Electronic Brake Force Distribution was developed to help distribute brake force between the front and rear wheels, depending on how the car is loaded. This also helps reduce stopping distances, particularly when carrying heavy loads.

 

I know it says it but that's just a car site...even in the tech documents I can't find it...

Brakes – 4-wheel anti-lock braking system (ABS) "from gm canada"
4- Wheel ABS "from Chevrolet usa"

edit: gm news

Brakes

Vented front disc brakes with single-piston calipers and full-cast rear drum brakes are standard on LS and LT. Four-wheel anti-lock brakes (ABS) are standard on 2LT and optional on 1LT and LS. Four-wheel disc brakes with StabiliTrak electronic stability control are standard on SS models. Cobalt also has a standard enhanced traction system (ETS) on vehicles equipped with an automatic transmission and ABS. ETS enhances traction by adjusting engine torque if wheel slip is detected.

Ensuring the car stops as confidently as it accelerates and corners are four-wheel disc brakes with standard ABS. The front brakes are from Brembo and have a performance-oriented fixed-caliper design, which resist fade better than floating caliper designs; the rear discs are vented for better heat dissipation. Along with these high-performance attributes, the Cobalt SS is also equipped with GM’s StabiliTrak electronic stability control system

 

Its a part of ESC, ABS prevents wheel lockup, EBD distributes brake force, its all part of the umbrella system ESC which is umbrella'd under "StabiliTrak".

Stabilitrak is just the system name, that system includes a bunch of different processes. Those processes have neat acronyms. we like acronyms. mmmm acronyms.

 

sorry man, stability control doesn't "have to involve" ebd... frig you can have stability control without abs "it wouldn't work very well though"

EBD's "main" purpose is for straight line braking, nothing to do with stability control

If anything... it should work in the order of EBD, ABS than ESC

 

im not sure I understand you...

Stabilitrak is effectively the name of the system, where as esc, abs, ebd are all processes within that system. You want to know if EBD is part of our car... yes it is... its subsystem of the abs system. The whole system is a process of Stabilitrak system.

ebd is coupled with abs. abs modulates the braking to prevent locking while ebd modulates the brakes for maximum braking ability. both are part of the same system which is on the cobalt as "electronic stability control" because of the electronic computer, using these processes to maintain stability.

ESC as a process and not as a system title, compares steering wheel angle to vehicle turning rate using a yaw rate sensor and applies brake accordingly.

 

leave my thread

and since no info can be found, I'm assuming we don't have EBD

 

ROFL!!! this guy! getting mad at the only person thats trying to help you understand what your talking about.

Call or email GM customer support and theyll proide you with the same answer, probably worded better with a letterhead attached. Maybe that will suffice for you.

 

Dude, you're an idiot and you need to be banninated. The guy is trying to help you and you have sand in your vaginal.

 

Someones got sand in their mangina.

 

If I recall correctly, the ATE (Continental Teves) ABS used on the Cobalt should be the Mk25e system which integrates electronic brake force distribution (EBD, sometimes referred to as electronic variable brake proportioning (EVBP)) along with ABS, traction control, and stability control functionality. If you look under the hood of the car there are only two brake lines coming off the master cylinder that go to the ABS ICU (integrated control unit) which splits out to the four wheels. There isn't a conventional mechanical proportioning valve used in this type of setup as the front-to-rear braking bias is controlled electronically via the ABS HCU (hydraulic control unit).

There seems to be some misconception over what EBD is and what it's not. As the name implies, it varies brake force front-to-rear under all normal braking conditions. Just like a conventional proportioning valve, under light braking it will apply more fluid to the rear brakes and therefore use them to a greater degree than under hard braking where most fluid is directed to the front brakes to reduce the chance the rear wheels will lock up.

With a conventional proportioning valve this is fixed and non-adjustable. If you're carrying rear passengers or more weight that affects the balance of the car you still have the fixed proportioning which may not be optimal. If the brake bias is off due to this there could be a greater chance of locking up the rear wheel(s) under certain braking conditions. With EBD the ABS controller can constantly monitor wheel slip (i.e. freely rotating to fully locked) and constantly and variably alter the rear braking pressure to compensate for different driving conditions and loads on the car. At lower speeds EBD-equipped vehicles will normally use the rear brakes to a greater degree, which can help balance the car and provide a longer service life to the front brakes.

EBD isn't just for straight line braking as it's applying or biasing braking force front-to-rear under all driving conditions. This can be very beneficial under certain conditions, such as heavily and suddenly braking while mid-corner but not quite hard enough to activate antilock on all wheels. The EBD functionality would reduce rear brake bias under that scenario and help prevent a rear wheel from locking up in the first place which maintains better vehicle dynamics.

You can't have EBD or stability control without ABS. They require being able to modulate brake pressure between front and rear axles or at individual wheels, respectively. Modern electronic traction control also uses ABS to apply brake pressure to spinning wheels but some older systems used things like up-shifting an automatic transmission, cutting ignition and/or fuel to reduce engine speed and so on to slow wheel speeds but none of those are as fast acting and unobtrusive as using ABS.

StabiliTrak is just a branding or name that GM now applies to their various electronic stability control (ESC) systems. Originally it was developed in-house with Delphi and used Delphi supplied ABS on the Cadillac models introduced with it in the late '90s but now GM uses the branding on ABS/traction/stability control systems also supplied by Bosch and ATE/Teves. The root of all these systems is still the antilock braking system and it's hydraulic control unit. This is what's needed to modulate brake pressure to provide antilock braking and also "bonus" things like ESC, EBD, ETC (traction control), emergency brake assist, etc.

On a four-channel ABS system like on the Cobalt (vice a three-channel system that modulates each front brake individually but controls both rear brakes together) this allows GM to use the antilock braking system to provide stability control by adding on a steering wheel angle sensor and yaw (rotational) force sensors and then using the ABS to apply brakes individually or diagonally at each end of the vehicle to counteract rotation. ABS without those sensors could still provide traction control and also brake force distribution depending on the ABS variant used.

 

^ that right thur is full of great info. good job man

 

thanks for the information... using the stuff you posted I did a quick search on our system..

ELECTRONIC VARIABLE BRAKE PROPORTIONING
Vehicles equipped with ABS use electronic variable brake proportioning (EVBP) to balance front-to-rear braking. The EVBP is used in place of a rear proportioning valve. The EVBP system uses the ABS system to control the slip of the rear wheels in partial braking range. The braking force of the rear wheels is controlled electronically by using the inlet and outlet valves located in the integrated control unit (ICU).

EVBP activation is invisible to the customer since there is no pump motor noise or brake pedal feedback.