Service Infiniti QX4 since 1996 of release
1. Introduction
2. The maintenance instruction
3. Routine maintenance
4. The engine
5. Cooling and heating systems
6. Power supply systems and managements
7. Start and charge systems
8. A transmissionnaja line
9. Brake system
9.1. Specifications
9.2. System of antiblocking of brakes (ABS) - the general information and codes of malfunctions
9.3. Check of a condition and replacement of brake lines and hoses
9.4. Replacement колодок disk brake mechanisms of forward wheels
9.5. Removal and installation of a support of the disk brake mechanism
9.6. Removal and installation of a brake disk
9.7. Replacement of brake boots of drum-type brake mechanisms of back wheels
9.8. Removal and installation of the main brake cylinder (ГТЦ)
9.9. Removal and installation of assemblage of the vacuum amplifier of brakes
9.10. Prorolling of brake system
9.11. Adjustment of a drive of a lay brake
9.12. Adjustments of a pedal of a foot brake
9.13. Adjustment of a spring of the valve-regulator sensitive to loading (LSV)
9.14. Adjustment of gauges-switches of stoplights and темпостата
9.15. Removal and hydromodulator ABS installation
9.16. Removal and G-gauge installation
9.17. Check of serviceability of functioning of wheel gauges ABS
9.18. Check of serviceability of functioning of the G-gauge
9.19. Check of serviceability of functioning of the relay приводного the hydromodulator electromotor
9.20. Check of serviceability of functioning of the relay of the electromagnetic valve of hydraulic modulator ABS
10. A suspension bracket and a steering
11. A body
12. An electric equipment
 












9-2-sistema-antiblokirovki-tormozov-abs-obshhaya-informaciya-i-kody-neispravnostejj.html

9.2. System of antiblocking of brakes (ABS) - the general information and codes of malfunctions


The arrangement scheme on the car of elements ABS

When the vehicle is equipped by brake system of usual type, sharp squeezing of a pedal of a foot brake leads to blocking of wheels. Coupling of a protector with a road covering is thus broken, and the car can go юзом, losing controllability. The system of antiblocking of brakes (ABS) prevents premature blocking of wheels, continuously operating speed of their rotation during braking at the expense of modulations of pressure of a hydraulic liquid in each of brake mechanisms.

ABS consists of two basic subsystems: electric and hydraulic. Four gauges of speed of rotation of wheels, the gauge enter into an electric part of system accelerations (G-gauge), the electronic block of management (ECU) and the complete set of connecting electroconducting (the arrangement Scheme see the car of elements ABS an illustration). The hydraulic part includes the pressure modulator, supports / wheel cylinders of brake mechanisms and connecting components lines of communication.

The principle of functioning of system is simple enough. Each of wheels is equipped by the individual gauge of turns. The gauge consists of a rotor (a ring with teeth in regular intervals located on its perimetre) and a sensitive element in a kind подмагниченной coils. The sensitive element of the gauge fixes the moments of passage by it teeths of a rotor and will transform the received information to the electric signals continuously transferred to the block of management ABS. By results of processing of arriving signals ECU receives the information on relative speed of rotation of each of wheels. While all four wheels rotate with identical frequency, ABS stays in a passive condition. As soon as any of wheels starts to be blocked, the management block fixes change of an entering signal and develops a command on operation of the modulator instantly dumping pressure of a hydraulic liquid in the brake mechanism of the corresponding wheel. As soon as normal rotation of a wheel is restored, the processor stops modulator functioning. We will notice that modulator switchings can occur to speed of hundred times in a second.

One more element ABS used on models Infiniti QX4, the gauge accelerations (G-gauge) is. Normally closed язычковый the G-gauge is established under assemblage of the central console in car salon (ahead of the lever of a lay brake) and serves for transfer on the module of management ABS the information on the overloads arising during dispersal or braking of a vehicle. The analysis of arriving signals together with the data accepted from wheel gauges, and the information on working parametres of the power unit allows the module processor to define reliability of coupling of protectors of wheels with a road covering and to exercise administration of functioning of the hydraulic modulator taking into account the given factor.

Actually the scheme of functioning ABS is much more difficult, than it can seem, therefore composers of the present Management do not recommend to owners of cars to make attempt of independent performance of repair of system. In case of occurrence of malfunctions it will be most reasonable to address to experts of car-care centre.

At revealing of any sort of infringements of functioning ABS the management block carries out system transition in emergency operation by switching-off of a food from the hydromodulator, thus corresponding diagnostic code is brought in memory of system of self-diagnostics, and the brake system continues to work in a usual mode (without ABS).


Problem diagnostics ABS


Preliminary checks

Before to start check of a condition of components ABS, it is necessary to make sure during a trial trip that a cause of infringement is not the manner of driving of the owner of a vehicle.

Check up level of a brake liquid. If level in norm, pass to a following stage of check, otherwise check up a condition brake колодок and investigate a hydraulic path of system on presence of signs of development of leaks. Will rectify the revealed faults, in case of need make replacement колодок, or correct level by addition in tank GTTS of corresponding quantity of a hydraulic liquid of a demanded grade.

Estimate serviceability of functioning of standard brake system (including checks of a condition of the vacuum amplifier and correctness of adjustments of brake mechanisms and a lay brake). Make necessary corrections.

Include ignition, and make sure of serviceability of operation of control lamp ABS (the Maintenance instruction see the Head). Start the engine, — control lamp ABS should go out. At refusals of a control lamp it is necessary to make reading brought in memory of the processor of codes of malfunctions (see more low), — told concerns as well cases of operation of a control lamp after dispersal of the car till the speed over 30 km/h and movements in the given mode within not less than 1 minute.


Reading of codes of malfunctions (DTC) ABS


Reading of codes DTC by means of control lamp ABS

At revealing by the processor of malfunctions in system in an instrument guard lights up and there is included control lamp ABS. Diagnostics of malfunctions of antiblocking system is among enough difficult procedures and composers of the present Management do not recommend to make it in house conditions. Nevertheless, it is possible to allocate a number of the elementary checks which can be quite successfully made own forces of the owner of the car and allow to define qualitatively a cause of a failure (see further).

Reading of codes DTC is made by means of the special scanner connected to a 16-contact diagnostic socket, located at the left under the panel of devices of the car.

Be alternative codes can считаны by means of control lamp ABS: by means of a wire-crosspiece earth the plug № 4 sockets CONSALT. Without squeezing out a pedal of a foot brake, include ignition. Later an order of 3 seconds the control lamp will start to give out flashing signals, highlighting brought in memory of the processor codes. The figure of tens code is defined by quantity of gleams of a lamp, duration on 0.6 seconds divided among themselves by pauses of the same duration, the figure of units of a code is separated by a pause duration of 0.9 seconds. The figure of units of a code is defined by quantity of gleams of a lamp, duration for 0.3 seconds. The moment of the beginning of reading is marked by delivery of a code 12 (one gleam, a pause, two gleams). Then again follows long (3.3 seconds) a pause after which the lamp starts to highlight stored in memory of the block of management codes.

At first the lamp always highlights a code of the beginning of reading (12), further there are codes DTC (to three successively, since the last) (Reading of codes DTC by means of control lamp ABS see an illustration). Process end proves to be true repeated высвечиванием a code 12. If the code 12 is highlighted only, and the refusal symptom takes place, the car should be driven away on a car repair shop for performance of standard diagnostic checks according to a card of symptoms. The reason of entering of a code in memory of the processor the most elementary malfunction can be, — first of all make following checks:

  • Make sure of correctness of level of a hydraulic liquid in tank GTTS;
  • Check up a condition of contact connections of corresponding electric chains;
  • Check up a condition of safety locks;
  • Check up a condition of brake system;
  • Check up a condition brake колодок;
  • Check up a condition of a pedal of a foot brake.

The following concerns number of diagnostic checks of symptoms entering into a card:

Too frequent operation ABS

The test And

Inadequate reaction of a pedal of a foot brake to squeezing

The test In

Excessiveness of length of a brake way

The test With

Refusal of functioning ABS

Test D

Vibrations and pedal noise at braking

Test Е

Refusal of operation of control lamp ABS at ignition inclusion

Test F

Refusal of deenergizing of control lamp ABS after realisation of start of the engine

Test G

Excessive vibrations of the car at operation ABS

Test Н

The identification card of codes of malfunctions ABS is resulted in Specifications.

It is necessary to charge performance of any regenerative repair to experts of car-care centre.


Clearing of memory of processor ABS

After elimination of the revealed malfunctions in system memory of the processor should be cleared. Memory clearing can be made either by means of the scanner, or by double grounding of the plug № 4 for 1 second during a 12.5-second interval, — during all time of removal of codes control lamp ABS remains included, then should go out.

At repeated attempt of reading the code 12 is highlighted even if all malfunctions have been eliminated.

More detailed information on сканерному to the input reader is resulted in the Head of the Power supply system and management.


On page back
9.1. Specifications
On the following page
9.3. Check of a condition and replacement of brake lines and hoses