To control the systems, the car is equipped with an instrument cluster in which control devices are installed: a voltage gauge, a tachometer, a speedometer, an engine temperature gauge, an oil pressure gauge, a fuel gauge and signaling devices
The connection of the contacts of the instrument cluster is shown in the electrical diagrams, and the location of the electrical connectors in fig. 1.
To remove the instrument cluster, first remove the trim by unscrewing the four screws.
Then unscrew the four screws securing the combination; disconnect the electrical connectors and remove the instrument cluster.
Repair the instrument cluster by block replacement of faulty instruments.
To replace devices, remove the protective glass and unscrew the nuts securing the defective device on the reverse side.
Speedometer
An electronic speedometer with a stepper motor is installed in the instrument cluster.
The speedometer consists of an arrow speed indicator, a trip meter and a daily trip meter. The daily counter has a reset button.
The speedometer works in conjunction with an electronic Hall sensor mounted on the gearbox.
When the vehicle is moving, the sensor is driven by the gear of the gearbox output shaft.
For one revolution of the sensor shaft, 6 pulses of electric current are generated.
These pulses enter the speedometer chip, are converted and fed to the microammeter, which indicates the speed of the car, and to the stepper motor, which rotates the drums of the distance indicators.
To check the health of the speedometer, it is necessary to assemble the electrical circuit shown in Fig. 3.
Using the G5-54 signal generator, apply rectangular pulses of positive polarity with an amplitude of 6 + 1 V with a duration of 200-250 μs to pins No. 10 and No. 3 of the KhRS connector.
The accuracy of the indications of the high-speed unit at the control points should fit: 60 km / h - 93.7-100 Hz 100 km / h - 157.2 - 166.6 Hz
According to the same principle, the accuracy of the readings of the counting node is checked.
At a frequency of 100 Hz, the drum "Km / h" should rotate 1 digit in one minute.
The error of the counting node should not exceed +1%.
To test the speedometer sensor, assemble the electrical circuit shown in fig. 4. For one revolution of the sensor roller, the LED should flash 6 times.
Tachometer
An electronic tachometer is installed in the instrument cluster to measure the engine speed.
The tachometer consists of a milliammeter and an electronic circuit.
The alternating voltage from the generator (taken to the rectifier unit from the stator phase) enters the amplifier, then it is converted in the microcircuit and enters the milliammeter, the arrow of which shows the number of revolutions.
The higher the generator speed, the more alternating current pulses enter the electronic part, the greater the angle of the tachometer needle deviates.
To check the tachometer, assemble the electrical circuit shown in fig. 5. From the G5-54 signal generator, apply rectangular pulses of positive polarity with an amplitude of 12–2 V and a duration of 200–250 μs to terminals No. 1 and No. 6 of the KhRZ connector.
At a frequency of 240 Hz, the tachometer should show 1000+100 min -1 , and at a frequency of 960 Hz - 4000 min -1 .
Fuel Gauge
In the instrument cluster, an electromagnetic fuel gauge is installed, which works in conjunction with a sensor installed in the gasoline tank.
The pointer is an electromagnetic ratiometer with fixed measuring coils and a moving permanent magnet.
The magnet is attached to the arrow axis of the pointer.
The pointer coils are wound at an angle of 90° on a special plastic frame.
The frame with the coils and the magnet is placed in specialth screen to exclude the effects of extraneous magnetic fields on them.
When current flows through both coils, a resulting magnetic field is created.
A permanent magnet, interacting with the magnetic field of the coils, is set in a position depending on the direction of this field.
The direction of the resulting magnetic field depends on the change in the ratio of currents in the coils, which is determined by the resistance value of the sensor, which in turn depends on the amount of fuel in the tank.
To check the fuel level indicator, it is necessary to assemble the electrical circuit shown in fig. 6.
When the RI resistance is turned on, the arrow should show "0", when R2 is turned on - "1/2", and when R3 is turned on - a full tank.
The deviation of the arrow from the indicated divisions is no more than the width of the arrow.
A serviceable fuel gauge sensor should have the following resistances: - with the float fully lowered 330 + 15 Ohm, and with the float fully raised - 11 + 5 Ohm.
With an intermediate float position of 70 mm from the sensor flange to the bottom of the float (measured perpendicular to the flange), the resistance should be 118 + 10 Ohm.
Temperature gauge
An electromagnetic ratiometric engine coolant temperature gauge is installed in the instrument cluster.
The device consists of a pointer and a sensor installed in the engine. The pointer device is similar to a fuel gauge, and the sensor is a semiconductor thermistor that sharply changes its resistance depending on temperature changes.
Changing the coolant temperature changes the resistance of the sensor, which causes a change in current in the pointer coils and the resulting magnetic field turns the permanent magnet and pointer to the appropriate position on the scale.
A working sensor at 25°C should have a resistance of 1400-1900 Ohm, and at a temperature of 80°C 200-270 Ohm.
To check the coolant temperature gauge, it is necessary to assemble the electrical circuit shown in fig. 7.
The pointer arrow should not deviate from the 80°C division by more than the width of the arrow.
Engine overtemperature alarm
In addition to the temperature indicator of the cooling system, the car is equipped with an engine overheating alarm.
The sensor automatically turns on the lamp in the instrument cluster when the coolant temperature reaches 104-109 ° C.
Engine lubrication pressure gauge
To control the pressure in the engine lubrication system, a ratiometric type electromagnetic indicator is used.
The device consists of a pointer located in the instrument cluster and sensor 23. 3839.
The pointer device is similar to a fuel gauge, and the sensor is a variable resistance, the value of which changes depending on the position of the membrane, which in turn changes its position on the pressure value.
To check the oil pressure gauge, it is necessary to assemble the electrical circuit shown in fig. 8.
When resistance R1 is connected, the pointer should show a pressure of 1.5 kg/cm 2 , and when resistance R2 is connected, it should show 4.5 kg/cm 2
The deviation of the arrow from the specified points is no more than the width of the arrow.
A working sensor should have a resistance of 290-330 ohms in the absence of pressure, at a pressure of 1.5 kg/cm 2 170-200 ohms, and at a pressure of 4.5 kg/cm 2 50—80 Ohm.
Emergency pressure warning lamp in the engine lubrication system
In addition to the lubrication pressure gauge, there is a signaling device in the instrument cluster.
When the pressure in the engine lubrication system drops from 0.4-0.8 kg / cm 2, the indicator lights up in the instrument cluster.
The signaling device works with an MM111-V type sensor.
When there is no pressure in the system, the sensor membrane bends away from the contacts and the lamp lights up, and when there is pressure, the membrane bends in the opposite direction, opens the contacts and the lamp goes out.
Voltage indicator
Ratiometric type voltage indicator, with fixed windings. The device of the voltage indicator is similar to the level indicator thenpiva.
To check the voltage indicator, it is necessary to assemble the electrical circuit shown in fig. 9.
For control, it is necessary to use a voltmeter with a limit of up to 30 V class I and an adjustable DC source (for example, B5-48).
Changing the voltage of the source, use the control voltmeter to determine the accuracy of the readings of the voltage indicator of the instrument cluster.
The error of the voltage indicator at points 12 and 14 V should not exceed +0.4 V.