Jeep Grand Cherokee

1993-1999 of release

Repair and operation of the car

Jeep Grand Cherokee
+ Cars of the Jeep Grand Cherokee brand
+ Settings and routine maintenance
+ Line six-cylinder engine
+ V8 engine
+ Procedures of the general and capital repairs of the engine
+ Cooling systems, heating and air conditioning
+ A power supply system and production of the fulfilled gases
+ System of electric equipment of the engine
+ Systems of decrease in toxicity of the fulfilled gases and engine management
+ Manual box of gear shifting
+ Automatic transmission
+ Transfer case
+ Coupling and transmission line
- Brake system
   General information
   System of anti-blocking of brakes (ABS) - the general information
   Replacement of blocks of disk brake mechanisms
   Removal, capital repairs and installation of a support of the disk brake mechanism
   Check of a state, removal and installation of a brake disk
   Replacement of boots of drum brake mechanisms
   Removal, capital repairs and installation of wheel cylinders
   Removal and installation of the combined valve (regulator)
   Removal and installation of the main brake cylinder
   Check of a state and replacement of brake hoses and lines
   Pumping of the brake system
   Functioning check, removal and installation of the vacuum amplifier of brakes
   Functioning check, removal, installation and adjustment of the sensor switch of stoplights
   Adjustment of the parking brake
   Replacement of cables of the drive of the parking brake
   Replacement of boots of the parking brake (disk brake mechanisms of back wheels)
+ Suspension bracket and steering
+ Body
+ System of onboard electric equipment
+ Governing bodies and methods of operation

System of anti-blocking of brakes (ABS) - the general information

ABS is established as the obligatory equipment on all models of the make of the car considered in this manual. The system is designed for the purpose of maintenance of controllability of the car, course stability and maximum efficiency of braking at high brake loadings regardless of a paving. It is carried out by tracking of relative speed of rotation of all four wheels and management of pressure in hydraulic lines of each wheel continuously in the course of braking. The system prevents premature blocking of wheels at sharp braking of the car.


Electronic control unit (ECU)

ECU is located on a mudguard left (from the driver's party) covered in a motive compartment of the car and is ABS system "brain". Two microprocessors accepting and analyzing at the same time arriving from sensors of each of wheels are a part of ECU. In case of refusal in the ABS system the system of its self-diagnostics gives the command for inclusion of yellow color of the alarm lamp located on the dashboard. Codes of malfunction of system are stored in memory of the program of diagnostics, however their reading is impossible without use of the DRB II scanner. Codes are stored in memory of system until it is not erased or after the 50th multiple start of the car. At shutdown of the battery of deleting of the written-down codes of malfunctions of the ABS system does not occur.

Hydraulic control unit (HCU)

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

Assembly of the pump with the motor provides giving in hydraulic contours of additional amount 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 the giving and returnable hoses and is put in action by the electric motor of a direct current operated by the ECU block.

Sensors of speed of rotation of wheels

Sensors of speed of rotation are installed on each of four wheels and at rotation of gear rotors of sensors develop the electric impulses sent to ECU and providing the last with information on frequency of rotation of wheels.

Sensors of speed of rotation of forward wheels are installed in rotary fists near gear rotors which napressovana on forward power shafts. Sensors of back wheels of a pribolchena to boards of brake mechanisms. Gear rotors of a napressovana on a half shaft of the back bridge.

Diagnostics of malfunctions and repair

If the control lamp on the dashboard lights up and remains included in use the car, the ABS system needs attention. Though full diagnostics of malfunctions of system requires the reader of the DRB II codes, some primary checks can be made before the car is driven away in dealer office:


  1. Check liquid level in the tank of the main brake cylinder.
  2. Raise a rug directly ahead of the console of a floor and make sure that the electric ECU socket is connected and reliably fixed.
  3. Check a condition of the electric socket of an electric motor of the pump of system.
  4. Check a condition of safety locks of ABS (The head Sistema of onboard electric equipment).
  5. Walk along plaits of wires of each of wheels, checking reliability of fastening of electric sockets and a condition of conducting.

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