Contents: Components ⤓ Diagnostics and repair ⤓
The anti-lock braking system (ABS) is designed to ensure vehicle control, stability and optimal braking under various braking conditions and on any road surfaces. The system operates by monitoring the rotation speed of each wheel and controlling the pressure in the brake pipe of each wheel during braking. This prevents wheel locking.
Components
Hydraulic block
The hydraulic unit includes the main brake cylinder, electro-hydraulic pump and accumulator unit, relay system and fluid reservoir.
a) An electric pump provides fluid pressure to charge the hydraulic accumulator, which maintains pressure in the brake system. The pump and the hydraulic accumulator are combined in a hydraulic unit.
b) The electromagnetic valve block modulates the pressure in the brake line during ABS operation.
Speed sensors
Speed sensors are mounted on each wheel and generate a small electrical signal as the sensor gears turn, sending a signal to the electronic controller indicating how fast the wheel is rotating.
The front wheel sensors are mounted on the front axles in a closed position relative to the sensor gears.
The rear wheel sensors are bolted to adapters on the rear axle.
Electronic controller
The electronic controller is mounted on a bracket in the luggage compartment and is the "brain" of the ABS system. The controller's functions include receiving and processing information from the wheel speed sensors and controlling the hydraulic pressure that provides protection against wheel locking. Even under normal driving conditions, the controller continues to monitor the system to detect faults within the system.
If a problem occurs within the system, the ABS warning light on the instrument panel will come on.
Diagnostics and repair
If the warning light comes on while the vehicle is moving and remains on, the ABS system requires attention.
A special electronic ABS tester is required to diagnose the system. At home, only basic checks can be performed.
a) Check the brake fluid level in the reservoir.
b) Open the trunk lid and remove the left panel. Make sure that the controller electrical connectors are firmly connected
c) Check the electrical connectors of the hydraulic unit.
d) Check the fuses.
d) Inspect the wiring harness going to each wheel and make sure all connectors are securely connected and the wires are not damaged.
If the fault is not corrected after the above checks, the vehicle must be taken to a workshop for diagnostics. Due to the complexity of the system, repair work can only be performed in a workshop.