BMW 5 Series E39

since 1996-2001 release

Repair and operation of the car

+ Introduction
+ Maintenance instruction
+ Current leaving and service
+ Engine
+ Cooling systems, heating
+ Power supply system and release
+ Engine electric equipment
+ Manual transmission
+ Automatic transmission
+ Coupling and power shafts
- Brake system
   Anti-blocking system
   Removal and installation of front brake shoes
   Removal and installation of a brake disk / support of a forward brake
   Removal and installation of back brake shoes
   Removal and installation of back brake supports
   Removal and installation of a brake disk of back wheels
   Measurement of thickness of a brake disk
   Brake fluid
   Removal of air from the brake system
   Replacement of brake pipelines
   Replacement of a forward brake hose
   Check of the vacuum amplifier of a brake
   Removal and installation of brake shoes of the parking brake
   Adjustment of the parking brake
   Removal and installation of the lever of the parking brake
   Removal and installation of a cable of the parking brake
   Check and replacement of the switch of a stoplight
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment
+ Schemes of electric equipment
+ System of onboard diagnostics

Anti-blocking system

The anti-blocking system (ABS) consists of the electrohydraulic control unit with the built-in electronic device, a control lamp of ABS and sensors of speed installed on wheels.
ABS interferes with blocking of wheels at sharp braking. Thanks to it at full braking the car remains operated. The driver feels action of ABS on a pulsation of a brake pedal and on noise of the hydrounit in a motive compartment.

Protection in an electronic control unit watches that it with defect (for example, break of a cable) or at decrease in the feeding tension of the rechargeable battery lower than 10.5 B ABS independently was turned off. It is displayed by fire on the dashboard of a control lamp of ABS. The ordinary brake system at the same time continues to work. The car when braking behaves so as if there is no ABS.
After inclusion of ignition of ABS makes self-diagnostics. Approximately through 3 with a control lamp dies away. If it burns longer or lights up during the movement, it is necessary to pay attention to the following:
   a) Stop the car, switch off the engine and again start it.
   b) Check tension of the rechargeable battery. If it makes less than 10.5 In, charge the battery.
   c) Check whether the contact of wires with a battery room of batteries is reliable.
   d) Lift and install the car on supports. Remove wheels. Check existence of damages of electric wires. More serious check of ABS has to be carried out by experts. By means of the special device of malfunction there can be schitana from memory and are eliminated.

Before carrying out electrowelding works it is necessary to rasstykovat shtekerny connection of an electronic control unit of ABS. Connection undocks only at the switched-off ignition. When performing painting works it is impossible to subject the control unit to influence of temperature above +85 °C.

ASC+T system

The ASC+T system (system of stabilization of stability and automatic adjustment of traction effort of the engine) interferes with skidding of back wheels at increase in gas, for example on the road with a wet covering as the revolving wheel cannot create sufficient driving force and coupling with the road. The considered system is built in the ABS control unit.

The control unit obtains information on the angular speed of wheels from sensors of wheels which are at the same time used as ABS sensors. If the back wheel begins to revolve, the DME system (an electronic control system of the engine) obtains information from the ABS/ASC+T control unit. The DME system reduces engine capacity by management of injectors. In addition the ignition moment can change. The effect of management at the same time is similar to an otpuskaniye the driver of the accelerator pedal. Engine capacity quickly decreases, wheels stop revolving. If it is not enough, the control system of traction effort applies brakes partially the revolving driving wheels. Action of the ASC+T system is displayed on the dashboard by a blinking of a control lamp.

In system there is an adjustment of traction effort. It interferes with short-term blocking of driving wheels on an equal paving thanks to brake operation of the engine. To the speed of 40 km/h the control system of traction effort creates blocking of differential. As the left and right wheel are applied brakes partially independently from each other, the ASC+T system works as the blocking differential with efficiency of blocking about 100%.

The ASC+T system registers malfunctions in the work. After inclusion of ignition on the dashboard the control lamp quickly lights up and dies away. If the lamp does not die away or burns during the movement, then it indicates existence of malfunctions in system. The car can move further, but the ASC+T system does not work.

At the movement with snow chains on deep snow or at start-off from the place from deep dirt it is expedient to disconnect the ASC+T system the switch located on the central console. It is possible to include system the same switch. At the following start of the engine the system joins.