Anti-lock braking system (ABS) consists of wheel speed sensors, a brake pedal switch, a gyro-electronic control module and warning lights in the instrument cluster

It includes a brake force distribution (EBD) system and a self-diagnosis system that detects malfunctions of system components.

ABS serves to regulate the pressure in the braking mechanisms of all wheels when braking in difficult road conditions and thereby prevents the wheels from locking.

The ABS system provides the following benefits:

- obstacle avoidance with a higher degree of safety, including during emergency braking;

- reduction of the braking distance during emergency braking while maintaining directional stability and controllability of the vehicle, including when cornering.

In the event of a system malfunction, diagnostic and maintenance functions are provided in the event of system failures.

The hydroelectronic control module receives information about the vehicle speed, direction of travel and road conditions from the wheel speed sensors and the throttle position sensor.

After switching on the ignition, the control unit supplies voltage to the wheel speed sensors, which use the Hall effect.

The sensors generate an output signal in the form of pulses. The signal changes in proportion to the rotational speed of the encoder pulse ring.

Based on this information, the control unit determines the optimum wheel braking behavior.

The following modes of operation of the anti-lock braking system are distinguished:

- normal braking mode. During normal braking, the intake valve is open, the exhaust valve is closed.

When you press the brake pedal, brake fluid is supplied under pressure to the slave cylinder and activates the wheel brakes.

When the brake pedal is released, the brake fluid returns to the brake master cylinder through the inlet and check valves;

- emergency braking mode. If, during emergency braking, wheel blocking begins, the module issues a command to the pump electric motor to reduce the supply of brake fluid, then voltage is applied to each solenoid valve.

The inlet valve closes and the brake fluid supply from the master cylinder and pump is shut off; the exhaust valve opens, and the brake fluid flows from the working cylinder to the main cylinder, and then to the reservoir, which causes a decrease in pressure;

- pressure maintenance mode. With the maximum decrease in pressure in the working cylinder, the module issues a command to maintain the brake fluid pressure, voltage is supplied to the inlet valve and is not supplied to the outlet valve.

In this case, the inlet and outlet valves are closed, and the brake fluid does not leave the working cylinder;

- pressure increase mode. If the module determines that the wheel is not blocked, then the voltage is not supplied to the solenoid valves, the brake fluid through the inlet valve enters the working cylinder, the pressure in which increases.

To diagnose and repair the anti-lock braking system, special equipment and accessories are required, so in case of its failure, contact a specialized service station.

Only the replacement of the wheel speed sensors and the hydroelectronic module is described here.

However, keep in mind that special equipment is required to remove air that may enter the valve system of the hydroelectronic module if unqualifiedly removed.

That is why we do not recommend removing the module unless absolutely necessary.

Removing the ABS unit

We install the car on a viewing ditch or lift

We mark the location of the tubes suitable for the valve body

Снятие блока ABS и датчиков скорости Рено ДастерСнятие блока ABS и датчиков скорости Рено Дастер

In the engine compartment on the right side, using a 11 mm open-end wrench or a special wrench for the brake pipe fittings, unscrew the fittings of the six brake pipes and disconnect the tubes from the hydraulic unit.

Raising the latch of the wiring harness shoe

Снятие блока ABS и датчиков скорости Рено ДастерСнятие блока ABS и датчиков скорости Рено Дастер

Disconnect the block from the control unit

We remove the brake pipe from the holder 1 and the wiring harness from the holder 2 of the bracket of the ABS unit

Снятие блока ABS и датчиков скорости Рено Дастер

Using a 13 head, unscrew the two bolts securing the bracket of the ABS unit to the body and remove the ABS unit with the bracket.

The ABS unit is attached to the bracket through two rubber grommets.

If the bushings are cracked or the rubber has lost its elasticity, the bushings are replaced.

Снятие блока ABS и датчиков скорости Рено Дастер

Having unscrewed with a key 10 two nuts securing the ABS unit to the bracket, we separate the unit and the bracket.

Install the ABS unit in reverse order.

We pump the brake hydraulic drive system (article - Replacing and pumping the hydraulic brake and clutch Renault Duster).

Removing the front wheel speed sensor

Raising the front of the car

Remove the front wheel arch liner

We securely fix the car on a stand

Снятие блока ABS и датчиков скорости Рено Дастер

We take out the holder of the block of the wiring harness from the hole in the mudguard of the body

Снятие блока ABS и датчиков скорости Рено Дастер

Sensor wiring harness block with holder removed

Снятие блока ABS и датчиков скорости Рено ДастерСнятие блока ABS и датчиков скорости Рено Дастер

Press the latch and disconnect the front wiring harness block from the sensor wiring block

We remove the rubber sleeve of the sensor wiring harness from the plastic holder located on the mudguard

Снятие блока ABS и датчиков скорости Рено ДастерСнятие блока ABS и датчиков скорости Рено Дастер

And two more couplings - from the bracket located on the amortization rack

Using the TorxT-30 wrench, unscrew the screw that secures the sensor to the steering knuckle

Снятие блока ABS и датчиков скорости Рено ДастерСнятие блока ABS и датчиков скорости Рено Дастер

We take out the wheel speed sensor from the steering knuckle

Before installation, we clean the installation site of the sensor, as well as the sensor itself.

Install the sensor in reverse order

Removing the rear wheel speed sensor

We hang out the back of the car and remove the wheel.

We fix the car on a stand.

Снятие блока ABS и датчиков скорости Рено ДастерСнятие блока ABS и датчиков скорости Рено Дастер

Using a flat screwdriver, unscrew the two plastic nuts securing the protective cover of the sensor wiring harness.

With a 10 head, unscrew the two nuts securing the casing

Снятие блока ABS и датчиков скорости Рено ДастерСнятие блока ABS и датчиков скорости Рено Дастер

We remove the casing from the arch and remove the wiring harnesses from the casing holders

By pressing the latch, disconnect the rear wiring harness block from the sensor wiring harness block

Снятие блока ABS и датчиков скорости Рено ДастерСнятие блока ABS и датчиков скорости Рено ДастерСнятие блока ABS и датчиков скорости Рено Дастер

We remove the rubber sleeve of the sensor wiring harness from the holder on the rear suspension arm.

Using the TorxT-30 wrench, unscrew the sensor fastening screw

We take out the sensor from the hole of the fist

Install the sensor in the reverse order.