Jeep Grand Cherokee

1993-1999 of release

Repair and car operation

System of antiblocking of brakes (ABS) - the general information

ABS it is established as the obligatory equipment on all models of mark of the car considered in a given Management. The system is designed for the purpose of maintenance of controllability of the car, course stability and peak efficiency of braking at high brake loadings without dependence from a road covering. It is carried out by tracing of relative speed of rotation of all four wheels and management of pressure in hydraulic lines of each wheel is continuous in the course of braking. The system prevents premature blocking of wheels at sharp braking of the car.

Components

The electronic block of management (ECU)

ECU it is located on a mudguard left (from the driver's party) a wing in an impellent compartment of the car and is system ABS "brain". Structure ECU includes two microprocessors accepting and analyzing simultaneously arriving from gauges of each of wheels. In default in system ABS the system of its self-diagnostics gives a command on inclusion of yellow colour of the alarm lamp located on the panel of devices. Codes of malfunction of system are stored in memories of the program of diagnostics, however their reading it is impossible without application of scanner DRB II. Codes are stored in memory of system until it will not be erased or after 50 multiple starts of the car. At switching-off of the battery of deleting of the written down codes of malfunctions of system ABS does not occur.

The hydraulic block of management (HCU)

HCU consists of the case of the valve and assemblage of the pump with the motor. In the valve case three electromagnetic valves switched on an electric signal - on one for each of forward wheels and one for both back wheels are placed, - which carry out modulation of hydraulic pressure in brake system in the course of braking. At squeezing of a brake pedal electromagnetic valves begin continuously and with high frequency vkljuchatsja-be switched off at the command of ECU, carrying out blocking of wheels of modulation of hydraulic pressure necessary for prevention in system contours.

Assemblage of the pump with the motor provides giving in hydraulic contours of additional quantity of the liquid necessary for prevention of blocking premature wheels. The pump is connected to the tank of the main brake cylinder by means of submitting and returnable hoses and put in action by the electromotor of a direct current operated block ECU.

Gauges of speed of rotation of wheels

Gauges of speed of rotation are established on each of four wheels and at rotation of gear rotors of gauges develop the electric impulses sent in ECU and providing last information on frequency of rotation of wheels.

Gauges of speed of rotation of forward wheels are established in rotary fists near to gear rotors, which напрессованы on forward power shafts. Gauges of back wheels приболчены to boards of brake mechanisms. Gear rotors напрессованы on a semiaxis of the back bridge.

Diagnostics of malfunctions and repair

If the control lamp on the panel of devices lights up and remains included while in service the car, system ABS requires attention. Though for full diagnostics of malfunctions of system the input reader of codes DRB II is required, some primary checks can be made before the car will be driven away in dealer branch:

If performance listed above preliminary checks does not help to reveal a cause of a failure, the car should be driven away in dealer branch of company Chrysler for carrying out of a full complex of diagnostics of system ABS with application of the special equipment.