Introduction

The electronic control unit processes signals from active sensor and the brake light control switch. The control unit then implements strategies to detect the wheel or wheels that are tending to lock (maximum slip between wheel and road surface). The

unit then modulates brake fluid pressure selectively for the front wheels and in tandem for the rear wheels (select-low function).

The ABS system modulates braking pressure in three basic stages:

1st pressure maintenance stage

2nd pressure reduction stage

3rd pressure increase stage

When the ABS is required to intervene, it remains active until the speed drops to 2.7 km/h but then cuts out to allow the car to stop. After each Key ON and when the car is moving faster than 6 km/h, the control unit tests solenoid and brake pump

operation. The control unit also tests the sensors when the car is moving faster than 12 km/h.

The body computer identifies the ABS as a component of the C-CAN network at the first Key ON