6.5. Antiblockade of system of brakes (ABS)
Work beginning
The system of antiblockade of brakes (ABS) serves for the regulation of the pressure in mechanisms of brake of all the wheels braking in difficult conditions of way of the prevention of the blockade of wheels. The system takes care:
– an obstacles turn with degree higher of security, inclusive in application of brake of emergence;
– reduction of a brake I walk in application of brake of emergence with stability preservation and controllability of the car, inclusive to his time.
In case of the bad functioning of antiblockading the function of system of the diagnostic one and the Repair of emergence of the work of the system is supplied.
The unity of electronic hydrocontrol (GEBU) of antiblockading the system receives the information on the speed and the direction of the movement of the car, and also in conditions of way of sensors of the speed of the rotation of wheels.
On basis of this information the unity of control defines the best way of the frenagem of wheels.
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Fig. 6.48. Elements of antiblockading the system of brakes: 1 – unity of electronic hydrocontrol of ABS (GEBU); 2 – sensor of speed of rotation of an advanced wheel; 3 – sensor of speed of rotation of a rear wheel; 4 – control the lamp of ABS and the electronic system of the distribution of force of brake; 5 – diagnostic contact capture
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Fig. 6.49. Hydraulic system of ABS: 1 – oil pipeline of brake of the right they dispatch the wheel; 2 – oil pipeline of brake of the left advanced wheel; 3 – brake oil pipeline of right behind goes round; 4 – oil pipeline of brake of the left rear wheel; 5 – hose of brake of the right dispatch the wheel; 6 – hose of brake of the left advanced wheel; 7 – brake hose of right behind goes round; 8 – hose of brake of the left rear wheel; 9 – unity of electronic hydrocontrol of ABS (GEBU); 10 – inhale the amplifier of brakes and cylinder of main brake
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The elements of antiblockading the system of brakes are shown in the fig. 6.48. The hydraulic system of antiblockading the system of brakes shows up in the fig. 6.49.
Management of ABS
Normal Frenagem. In the moment of the normal frenagem the valve eletromagnética is cut of the power, the entry valve is opened, the production valve is closed. When will it hold tight a fluid of brake of pedal of brake below the pressure if it moves for the wheel cylinder he was seeing the valve eletromagnética and it puts a brake in the action. In a brake pedal otpuskaniye when it flowed of brake it it turns to the brake cylinder main road to valve of entry and the valve backpressure.
Repairal way. If in the moment of the hard-working blockade of brake of emergence of a wheel it begins, GEBU gives out the order of the reduction of the provision of fluid of brake in the valve eletromagnética, then movements of tension of each valve eletromagnética. The entry valve is closed, and the provision of fluid of brake in the main cylinder is blockaded; the production valve opens, and the brake fluid comes that he was seeing the cylinder of wheel to a tank that causes the reduction of pressure.
Way of maintenance of pressure. In the moment of the very reduction of pressure in the questions of cylinder of wheel GEBU to order of the maintenance of the pressure of fluid of brake in the valve eletromagnética, the tension removes the valve of entry and does not remove the valve of production. At the same time the entry and the valves of production are closed and curb the fluid it does not leave the cylinder of wheel.
Increase way in pressure. If GEBU defines this the wheel is not blockaded, cuts the power to valve eletromagnética. The tension in valves eletromagnéticas does not move, the brake fluid was seeing the valve of entry it comes to the cylinder of wheel in which the pressure increases.
Electronic system of distribution of force of brake (EBD)
The electronic system of the distribution of force of brake (EBD) is a subsystem of ABS that serves to secure the efficient union of rear wheels with the surface of the way.
Besides, the system EBD prevents to blockade and a current of rear wheels in the partial ways of the frenagem.
In the presence of the system of the distribution of force of brake the brake effort is supported near to the best to value and regulated by the electronic system that there allows to do without the ordinary regulator of the pressure.
Like regulator of pressure – the mechanical device, his opportunities they limit themselves from the point of view of the realization of ideal distribution of force of brake between advanced and rear wheels, and also flexible distribution of force of brake depending on the point of the load of the car. Besides, the bad functioning of the mechanical regulator of the pressure the driver, as a rule, is not.
The electronic system of the distribution of force of brake (EBD) addresses for the unity of control ABS. In the moment of the movement the system of the distribution of force of brake constantly defines
the point of the sliding of each one of wheels of the cars also regulates the pressure of liquid of work in mechanisms of brake of rear wheels so that it exceeded the pressure in mechanisms of brake of advanced wheels.
In case of detection of failure (it labels.) of the system of the distribution of force of brake (EBD) in a devices combination to lamp of control of EBD it illuminates 6.1 (and the parking brake).
6.1 fixes
Work of the ABS and systems EVD in the moment of detection of bad functioning
The advantages of the electronic system of the distribution of force of brake are the next thing.
1. Improvement of Repair of the main system of brakes.
2. Compensation of a difference of coefficients of friction (for each wheel of the car).
3. Lack of necessity of the traditional regulator of pressure.
4. The alarming system on bad functioning through a control lamp in the panel.
Management of lamps of control
The agreement of lamps of control of ABS and EBD in a devices combination is shown in the fig. 6.50.
Module of a lamp of control of ABS. The lamp of control of ABS shows the degree of the operabilidade of ABS.
The control lamp illuminates in the next cases:
– in a phase of inicialização after ignition inclusion (3 c);
– in case of the prohibition of action of ABS in bad functioning;
– if EBU does not gather in the included ignition;
– in way of diagnostic one.
Module of a lamp of control of EBD. The lamp of control of EBD shows the degree of the operabilidade of EBD.
The control lamp illuminates in the next cases:
– during a phase of inicialização after ignition inclusion (3 c);
– in case of the prohibition of action of EBD in bad functioning;
– if EBU does not gather in the included ignition;
– in the moment of the connection of the parking they brake or insufficient level of fluid of brake.
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TO OBSERVE
The phenomena supplied down are not signs of the bad functioning of ABS or EBD.
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Characteristics of work of the system ABS
Sound checking the system ABS. In the launch of the motor of a driving compartment the deaf blow is heard sometimes. One adheres with the check of the operabilidade of the system.
Sound during the action ABS. The sound of Repair of the electric motor of the hydroblock of ABS (when a sound is howling). The sound which plantation is accompanied with the vibration of a pedal of a brake.
During the action of ABS of the chassis of the car there are sounds that are caused by the cycles if they repeat of the frenagem and a disinhibition of wheels (the impacts that go of a support of the triangular form of interruption; a tires scratch).
Great brake I walk. In some pavings, inclusive in covered ways of snow or a covering of gravel, the brake the way of the equipped cars of ABS can be more usual. Therefore, in the moment of the movement along such ways the owner of the car must show the care and move in the lowered speed.
The vibration of a pedal of a brake is the normal phenomenon.
The codes of the bad functioning of ABS are specified in the etiquette. 6.2.
6.2 fixes
Codes of bad functioning of ABS of brakes
The part of end of the capture of one unity of electronic hydrocontrol of ABS shows off in the fig. 6.51. The addressing of a part of end of the capture of one unity of electronic hydrocontrol of ABS happens in the etiquette. 6.3.
6.3 fixes
Addressing of contacts of the capture of one unity of electronic hydrocontrol (GEBU) of the system ABS
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Number
contacts
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I address (objective of contact)
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Maximum
current
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Minimum
current
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To observe
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1
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-
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-
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-
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2
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-
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-
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-
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3
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-
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-
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-
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4
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Lamp of control of EBD
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30 мА
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5 мА
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5
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Interface of diagnostic one
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6 мА
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3 мА
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6
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The right dispatches the sensor of wheel
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16 мА
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6 мА
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7
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The right dispatches the sensor of wheel
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16 мА
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6 мА
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8
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Straight behind wheel sensor
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16 мА
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6 мА
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9
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-
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-
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-
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10
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When wheel sensor was left behind
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16 мА
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6 мА
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11
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Advanced wheel sensor left
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16 мА
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6 мА
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12
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"Weight"
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5-15 AND
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2,5 AND
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Management of ABS
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13
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Tension and / 1 (eaten of lapan)
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5-15 AND
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2 AND
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Management of ABS
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14
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Tension and / 2 (provision of power of the electric motor)
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20-39 AND
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10 AND
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Management of ABS
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15
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"Weight"
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20-39 AND
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10 AND
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Management of ABS
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16
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-
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-
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-
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17
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-
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-
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-
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18
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-
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-
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-
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19
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-
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-
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-
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20
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Lamp of control of ABS
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30 мА
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5 мА
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21
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-
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22
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Switch of sign that brakes
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10 мА
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5 мА
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23
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Straight behind wheel sensor
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16 мА
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6 мА
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24
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Ignition
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1 AND
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500 мА
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25
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When wheel sensor was left behind
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16 мА
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6 мА
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26
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Advanced wheel sensor left
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16 мА
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6 мА
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Removal and installation of elements of antiblockading the system of brakes
Unity of electronic hydrocontrol (GEBU) ABS
Removal
Withdraw the filter of air and a tube of branch of airintaking.
Desconecte oil pipelines of brake of GEBU.
The moment of an inhalation of pins of fixation of an arm of GEBU – 8-10 N · m.
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PREVENTIONS
The desmontagem of GEBU is not allowed.
The transport and the storage of GEBU in the vertical position with the very quite warmly dressed openings are allowed.
It does not establish the liquid of GEBU.
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Installation
It executes the installation GEBU as debit to be, the return to the removal.
Hold tight pins of the fixation of GEBU the moment of 8-10 N · m, an union of fixation of oil pipelines of brake the moment of 13-17 N · m.
Check of tension of a sign of sensors of wheel
Install the car in the elevator, put the brake of parking out.
Separate the capture of contact of GEBU and carry out that they check contacts of a part do away with the contact capture.
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TO OBSERVE
When it checks withdraw a double armband of the capture of contact and it annexes the device of control to wires from abroad, in front of contacts of the capture. The connection of measuring probes of the device to contacts does not supply the connection fiável
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Through a prover or an oscillograph they check the tension of a sign of sensors of wheel, making spinning the corresponding wheel with a speed of 0.5-1 with - 1.
Connection of the device of control of check of tension of a sign of sensors of wheel
Sensor of wheel of Number of contacts of the capture
The left thing ahead.............. 11, 26
Right ahead............ 6, 7
The left back.................. 10, 25
Right behind................ 8, 23
Sign tension in the moment of measurement through an oscillograph, in:
lower level..... 0,535 (in 7 мА you act)
high level..... 1,050 (in 14 мА you act)
Sensors of speed of rotation of wheels
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Fig. 6.54. Sensor of speed of rotation of an advanced wheel: – they contact 1 with the capture of the sensor of the speed of the rotation of an advanced wheel; 2 – sensor of speed of rotation of an advanced wheel
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Fig. 6.55. Sensor of speed of rotation of a rear wheel: 1 – sensor of speed of rotation of a rear wheel
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The sensor of the speed of the rotation of an advanced wheel is shown нарис. 6.54, a rear wheel – in fig. 6.55.
Removal of the advanced sensor of wheel
In a driving compartment they separate the capture of contact of the advanced sensor of wheel.
Withdraw the sensor of wheel.
Removal of the rear sensor of wheel
Separate the capture of contact of the rear sensor of wheel in a nave of wheel (to see the fig. 6.55).
Withdraw the drum of brake, having unscrewed the screw of his fixation to a wheel nave.
Put out four pins of the fixation of a nave of a rear wheel to a ray of a rear support of the triangular form of interruption.
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PREVENTION
Do not withdraw the sensor of wheel of a few punches of nave of the hammer as it can lead to a sensor exit out of the Repair.
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Removal of air of a hydraulic acionador of brakes
The Repair is executed for the efficient removal of air of a hydraulic acionador of brakes and filling of the fluid of brake of the hydraulic block of antiblockading the system of brakes, oil pipelines of brake and the cylinder of main brake.
For the removal of air of a hydraulic acionador of brakes of the equipped cars of the antiblockade of system it HI EXAMINATION to diagnostic unity is in use. Executing this Repair the device joined the diagnostic capture below the panel makes working valves eletromagnéticas and the electric bomb
system antiblockade.
Withdraw a cork of a tank of a hydraulic acionador of brakes and fill a tank of the fluid of brake.
Since a dolivka only uses the POINT 3 or fluid of brake of the POINT 4.
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PREVENTION
In the moment of the blow of fluid of brake in a painting and the covering of varnish of a body immediately they take away his waters of great number while washing.
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TO OBSERVE
When it uses special installation of the removal of air it does not hold tight a pedal of brake.
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Annex a transparent plastic hose to the union of bomb in the wheel cylinder and lower another end of a hose in the transparent capacity for the filled half of the fluid of brake.
Annex the device HI-SCAN to the diagnostic capture located below the panel.
Through HI-SCAN device they light the electric bomb and valves eletromagnéticas of antiblockading the system.
Carry out Repairs like directed, it exposed the device HI-SCAN.
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PREVENTION
For the prevention of the burn - out of windings of the electric motor of the bomb of antiblockading the system they do not exceed the most admissible time of his work specified in the fabric of device HI-SCAN.
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Several times hold tight a pedal of brake, opening the union of bomb until in the next liquid air bottles then they hold tight the union of bomb they stop appearing.
Carry out the Repair described in other wheels of the car in the next order: a rear right wheel (in the direction of the movement of the car), an advanced left wheel, a few back left the wheel, advanced right wheel.
Moment of an inhalation of unions of extraction through bomb of 7-13 N · m.