Antilock Brakes / Traction Control Systems: Description and Operation

The Teves four wheel Anti-lock Brake System (ABS) is an integral power brake system that increases driver safety during severe braking conditions.
The hydraulic system is divided into three circuits with independent front control and combined rear control. This type of system is referred to as a three channel system.

The system utilizes an electronic brake control module (EBCM) to continually monitor individual wheel speed to detect wheel lockup. When all or an individual wheel locks-up the EBCM energizes an electro/hydraulic solenoid that bleeds off pressure to the wheel cylinder that is causing the lock-up. This prevents wheel lock-up that could cause poor vehicle control. During anti-lock operation brake pedal pulsation will be felt along with a possible rise in brake pedal level.

The system operates in to modes of operation, normal, and anti-lock mode. During normal operation the brake system operates as a standard brake system. The EBCM continually conducts electrical self test during normal operation to test electrical system integrity. If the EBCM detects a malfunction the "ANTILOCK" lamp will be illuminated and only normal brake operation will be possible. When the EBCM detects the need for anti-lock operation it controls various solenoids and valves to prevent wheel lockup. When the vehicle stops or the need for antilock operation no longer exist the EBCM switches back to normal mode.