Audi A4

since 1994 release

Manual of the car

Audi A4
+ Running gear
+ Regular servicing
+ Engines
+ Turbo-supercharging
+ System of an exhaust
+ Cooling system
+ Fuel tank and fuel pump
+ Air filter and channels of absorption
+ System of injection
+ Coupling
+ Transmission and main transfer
+ Suspension bracket of wheels and steering
+ Brakes
+ Wheels and tires
+ Electrotechnical equipment
+ System of ignition
+ Lighting
+ Alarm equipment
- Tools and devices
   Check of control tools and bulbs
   The combined device
   Indicator of amount of fuel
   Indicator of temperature of cooling liquid
   Auxiliary devices
   Control bulbs above in the combined device
   Control bulb of cooling liquid
   Control bulb of level of brake fluid
   Control bulb of pressure of oil
   Control bulb of indexes of turns
   Control bulbs in devices of a round form (and nearby)
   Control bulb of indexes of turn on the trailer
   Control bulb of ASR
   Control bulb of the lock of ignition
   Control bulb of high beam headlamps
   Control bulb of a safety cushion
   Control bulb of ABS
   Control bulb of the parking brake
   Control bulb of accumulator charging
   System of autocontrol of the car
   Ignition lock
   Check of switches
   Alarm buzzer of lighting
   The warmed back glass
   Check of screen wipers and windscreen washers
   Engine of screen wipers
   The help at malfunctions
   The gulf of liquid for washing of glasses
   System of washing of headlights
   Adjustment of a mirror with the electric drive
   Central lock
   Window regulators with the electric drive
   Sliding/removable roof with the electric drive
   Radio receiver
   The antenna on back glass
+ Heating and ventilation
+ Body details
+ Salon
Search of malfunctions
Technical characteristics


Control bulb of cooling liquid

Cars without system of autocontrol

If during the movement the control bulb of cooling liquid begins to blink, at once stop:


  1. Check the level of cooling liquid (the head the Cooling system) and if it is necessary, small portions add cooling liquid or water. Be careful, opening a locking cover of the cooling system.
  2. If the engine too hot, and the level of cooling liquid normal, check whether enough the viscous fan powerfully rotates (the noise reminding operation of the turbine at gas supply?).
  3. The car with the electric fan: the fan rotates if the engine too hot?
  4. The fan of a radiator does not work, despite the heated radiator.
  5. Last opportunity: the general sensor of a control bulb and the indicator of temperature of cooling liquid is faulty.

Search of malfunctions

Control bulb of cooling liquid


  1. Check of a control bulb: the control bulb blinks for functional control at inclusion of ignition. If there is no it, then:
  2. Check the corresponding safety lock (the head the Electrotechnical equipment).
  3. If it as it should be, then dismantle the combined device, dismantle a control bulb and check.
  4. If a bulb as it should be, check a wire and/or replace/repair the combined device.
  5. Check of the sensor of temperature on the engine: if the control bulb blinks also at the cold engine or at a working temperature of the engine (at the working engine!), temperature sensor can be faulty. About its check read in this chapter above in the section Indicator of Temperature of Cooling Liquid.
  6. The sensor of level of cooling liquid in a broad tank:
  7. The sensor is inserted into a broad tank from below and strongly connected to a tank.
  8. At the blinking bulb, despite the correct level of cooling liquid, disconnect sensor wires.
  9. If the blinking stops, then clean the sensor inside in a tank or replace a tank.