Audi 80/Avant (B4)

since 1991-1995 release

Repair and operation of the car



Audi 80/Avant
+ Technical specification
+ Engines
+ System of production of the fulfilled gases
+ Cooling system
+ Fuel tank and fuel pump
+ Air filter and airintaking channels
+ System of injection
+ Coupling
+ Transmission and transmission
+ Suspension bracket and steering
+ Brake system
+ Anti-blocking system of brakes
+ Wheels and tires
+ Body electrical system
+ System of ignition
+ Lighting
+ Signaling devices
- Devices and auxiliary devices
   Check of indicators and signaling devices
   Elements of a combination of devices
   Speedometer
   Tachometer
   Hours
   Indicator of amount of fuel
   Indicator of temperature of cooling liquid
   Voltage stabilizer
   Additional devices
   The top indicators in a combination of devices
   Indicator of cooling liquid
   Indicator of the brake system
   Oil pressure indicator
   Indicators of indexes of turns
   Lower indicators
   Indicator of a charge of the rechargeable battery
   Indicator of indexes of turn of the trailer
   Safety cushion indicator
   Indicator of anti-blocking system
   Indicator of driving beam
   Indicator of the parking brake
   System of self-examination
   Switches
   Ignition lock
   Check of switches
   Buzzer of shutdown of lighting and radio
   Lighter
   Heating of back glass
   Check of screen wipers and windscreen washers
   Screen wiper engine
   List of malfunctions
   Screen wiper of back glass
   List of malfunctions
   Replenishment of a washer reservoir of glasses
   System of washing of headlights
   Audio system
   Antenna of back glass
   Electric regulation of external rear-view mirrors
   System of locks with the central management
   Power windows
+ Heating and ventilation
+ Body elements
+ Search of malfunctions
+ Specifications





Oil pressure indicator

Pressure of engine oil in Audi 80 is controlled by two switches with a hydraulic actuator and the control unit with a buzzer (both last are combined in system of minicheck). If to represent simply, then control is exercised as follows:

  • At the included ignition to one of contact conclusions of the indicator of pressure of oil food constantly arrives.
  • If oil pressure (at the idle engine) lower than 0,3 bars — become isolated contacts of the switch with a hydraulic actuator of 0,3 bars thanks to what connection on "weight" to the second contact conclusion of the indicator is created – the lamp lights up (blinks).
  • If after the beginning of operation of the engine pressure of oil rises, then contacts in the switch open, and the lamp dies away.
  • Additional control is exercised on models with 4-and 5-cylinder engines by means of the switch with a hydraulic actuator of 1,8 bars, on models with the 6-cylinder engine by means of the switch with a hydraulic actuator of 2,5 bars.
    The switch with a hydraulic actuator and the control unit is a part of the system minichecks: if pressure of oil falls below the switching pressure of 1,8 or 2,5 bars, then its contacts become isolated, creating thereby connection on "weight" to the control unit in system of minicheck – the switch with a hydraulic actuator of 0,3 bars at this time also does not join.
  • The system of minicheck allows a lamp of the indicator to flash only in case pressure of oil falls below switching longer, than on 1 with and engine speed at the same time makes more than 2100 rpm.
  • In addition the system of minicheck publishes a warning noise signal. Sense of all this in prevention of damages of the engine because of too low pressure of oil (for example because of its too low level).

Switches with a hydraulic actuator

Sleva: 4-cylinder engine: both switches with a hydraulic actuator 0,3 bar (1) and 1,8 of bars (2) are located on a flange of an oil filter (3).

On the right: 5-cylinder engine: switches with a hydraulic actuator 0,3 bar (1) and 1,8 of bars (2) are located at the engine below the thermostat case at the left.

Sleva: near a pulley of a bent shaft on models with the 6-cylinder engine the sensor of the indicator of temperature of oil (1) is located. Directly near it the switch with a hydraulic actuator 2,5 bar (2) is visible. Behind it the switch with a hydraulic actuator of 0,3 bars is located. On the models equipped with additional devices, the switch of 0,3 bars is combined with the oil pressure sensor.

On the right: in this shtekerny connection (shooter) located behind at the left head of the block of cylinders all wires to the oil temperature sensor, the sensor of pressure of oil and both switches with a hydraulic actuator are collected.

Insulators of switches with a hydraulic actuator are painted in different colors.

  • The switch with a hydraulic actuator of 0,3 bars is painted in brown color. At the cars equipped with the manometer the oil pressure sensor supplied with in addition switching contact for the indicator is in the place of this switch.
  • The switch with a hydraulic actuator of 1,8 bars is painted in white color (models with 4-and 5-cylinder engines).
  • The switch with a hydraulic actuator of 2,5 bars is painted in red color (models with the 6-cylinder engine).

Search of malfunctions

 PERFORMANCE ORDER

  1. If the indicator flashes (perhaps with an additional buzzer) at the working engine, you need to stop immediately!
  2. To immediately kill the engine, to check oil level. If it is normal:
  3. To disconnect a wire from the switch with a hydraulic actuator of 0,3 bars, to leave it to be groundless, include ignition: if the indicator continues to burn, it means that in conducting there was a short circuit on "weight" – is harmless for the engine.
  4. To disconnect a wire from the switch with a hydraulic actuator of 1,8 bars (or 2,5 bars) and to bring to "weight", to include ignition: if the indicator continues to burn or the warning buzzer continues to sound, so malfunction concerns system of minicheck or check – is harmless for the engine.
  5. If you observe others, not given above, effects, then it is possible to suspect that supply of the engine with oil is broken. Further the car needs to be towed!
  6. Perhaps, one of switches with a hydraulic actuator is faulty. Sometimes it joins again if to shake his shtekerny uvula.
  7. If the indicator of pressure of oil does not flash after inclusion of ignition:
  8. At first to check a safety lock (the head the Body electrical system).
  9. To disconnect a wire from the switch with a hydraulic actuator of 0,3 bars and to bring to "weight": if now the indicator lights up, so the switch was faulty. If it still does not react, so conducting or a bulb are faulty.

Check of the control unit

 PERFORMANCE ORDER

  1. To disconnect a wire from the switch with a hydraulic actuator of 1,8 bars and to leave it to be groundless. To start the engine and to leave to work with a frequency about 2500 rpm.
  2. After 2 seconds of work the indicator and three times has to flash to sound a buzzer. Otherwise the system of minicheck is faulty – to replace!
  3. If only the indicator flashes, but the buzzer does not work, so conducting from the plug of the generator 61 (D+) is interrupted.
  4. If the indicator flashes and the buzzer at the connected wire to the switch with a hydraulic actuator with a frequency of turns of the engine is distributed about 2500 rpm, so the switch of 1,8 bars (2,5 bars) – is faulty provided that engine oil level as it should be.
  5. To leave the engine to work at single turns, to disconnect a wire from the switch of 1,8 bars (or 2,5 bars) and to leave to be groundless. If now the bulb and a buzzer work, so conducting from the plug 1 (a rotation frequency signal) and systems of minicheck is interrupted.

Replacement of the switch with a hydraulic actuator

 PERFORMANCE ORDER

  1. To buy the necessary switch with brown, white or red isolation and one sealing ring.
  2. To tighten the switch with a hydraulic actuator the moment of 25 N • m.







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