ABS elements
1 - control unit; 2 - vacuum booster with the main cylinder; 3 - ASR switch; 4 – control lamp ASR; 5 - control lamp ABS; 6 – a control lamp of level of a brake liquid and inclusion of a parking brake; 7 - diagnostic socket; 8 - brake mechanism of the rear wheel; 9 - brake signal switch; 10 - brake mechanism of the front wheel
Control units «Bosch 5.7»
a - ABS control unit; b - ABS / EDS / ASR control unit
On some cars, an anti-lock braking system is additionally installed in the brake system (ABS). ABS is an automatic device that intermittently brakes the vehicle and prevents the wheels from locking, thereby maintaining their grip on the road. The use of the system allows you to increase the braking efficiency, improve the handling and stability of the car on the road.
ABS consists of a standard brake system and additional components, which include control unit 1 (see fig. ABS elements) and wheel speed sensors installed in the brake mechanisms of the front 10 and rear 8 wheels, with sensor disks in the wheel hubs.
Additionally, on models with ABS, traction control can be installed (ASR) and electronic differential lock (EDS).
ASR prevents wheel spin during acceleration by acting on the engine management system, resulting in engine torque being reduced to the optimum value. ASR can be switched off with the switch 3.
EDS constantly determines the angular speed of the drive wheels, receiving signals from speed sensors. If the angular velocities do not match, the slipping wheel is braked until the angular velocities of the driving wheels are equal, thereby creating the effect of differential lock. The system only works in a straight line. ABS, EDS and ASR are combined in a common control unit. ABS control units «BOSCH 5.7» and ABS/EDS/ASR «BOSCH 5.7» (see fig. Control units «Bosch 5.7») can be distinguished by appearance.
Attention! Disconnect blocks with wires ABS only at the switched off ignition.
Attention! Before starting any work on the ABS components, be sure to disconnect the wire from the terminal «-» battery.
Attention! Before carrying out electric welding on a car, disconnect the block with wires from the ABS control unit.
Attention! Do not use fluffy or shedding cloths for cleaning.