Audi A4

since 1994 release

Repair and operation of the car

A4 Audi
+ 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
   Minus is connected to weight
   The help for orientation in the electrotechnical equipment of the car
   Connections of wires
   Central switching knot
   Support of additional relays
   Box for electronics
   Relay and control units
   Switching relay
   H-contact of the relay of unloading
   Table of the relay and control units
   Safety locks
   Table of safety locks
   + Electric circuits
   - Accumulator
      Correctly picked up accumulator
      As far as the accumulator reserve is enough?
      Check of level of acid in the accumulator
      Check of a charge of the accumulator
      Battery charging
      Start of the engine with the discharged accumulator
   + Generator
   + Starter
+ System of ignition
+ Lighting
+ Alarm equipment
+ Tools and devices
+ Heating and ventilation
+ body Details
+ Salon
Search of malfunctions
Technical characteristics

Check of level of acid in the accumulator

Liquid in the accumulator consists of the sulfuric acid diluted with the distilled water. The part of this water can evaporate or break up to hydrogen and oxygen during a battery charging.

The so-called accumulator which is not subject to maintenance which at the expense of the bigger volume of liquid has to, under normal circumstances is installed in Audi, throughout all term of the service to do without addition of the distilled water.


  1. Liquid in the accumulator has to reach, at least, lower of two marks put with a varnish on the case or strips which are beaten out on it, and it is good to cover the upper edge of plates.
  2. If the level of liquid fell, unscrew a stopper.
  3. If the accumulator is charged normally, add the distilled water to the top mark or is 15 mm higher than the upper edge of plates.
  4. If the accumulator was strongly discharged, add so much water, how many it is necessary to cover plates. At charging liquid level considerably rises.
  5. Add the distilled water to the top mark only after a battery charging.
  6. The amount of the added water has to be well dosed, differently the accumulator will be crowded.
  7. The crowded accumulator perekipat too much, acid acts from under a stopper

Dismantle of the accumulator

Dismantle of the accumulator: remove a decontamination hose. In the beginning weaken the plug of minus (3), then remove facing of a plus pole (4) and unscrew the plug of plus (5). Now it is possible to weaken a bolt (1) on a fixing guard (2) bases of the accumulator.


  1. In the beginning be convinced available a code for the coding device against theft of the radio receiver in order that it could be made active again after installation.
  2. In the beginning always disconnect the wire connected to minus in order that in the course of further work there was no short circuit.
  3. Weaken a nut on the plug of a minus pole, disconnect the plug.
  4. Weaken the plug of a plus pole and disconnect.
  5. Unscrew a bolt of a fixing level at the accumulator basis, take out a bolt and remove a level.
  6. Remove a plastic hose of the central decontamination.
  7. Remove the accumulator.
  8. At installation connect a wire to plus in the beginning, then the minus plug.
  9. It is possible to change wire plugs only if to make big effort as the head of a plus pole is thicker than a head of the minus.
  10. Do not forget about a hose of the central decontamination.
  11. In the presence of the radio receiver with a code against theft again enter number of a code.

Care of contacts of the accumulator


  1. Wash away oxide crystals warm alkaline water or process "Noutralon" of firm Warta.
  2. Grease heads of poles of the accumulator and the plug of wires with means for protection against acid (Bosch "Ft 40 v 1").
  3. It is impossible to grease lateral faces of heads of poles and inside of plugs, differently there can be difficulties with contact.