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
   For what ventilation of the fuel tank is necessary?
   The fuel level indicator sensor in the fuel tank
   Fuel-supply lines
   The fuel pump with the electric drive
   Dismantle of the petrol pump with the electric drive
   Replacement of the fuel filter
+ 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
+ Heating and ventilation
+ Body details
+ Salon
Search of malfunctions
Technical characteristics


The fuel pump with the electric drive

In all versions of Audi A4 engines the fuel pump with the electric drive is inserted into the case of an inlet collector below in the fuel tank.
Positive current he receives via the relay of the fuel pump (the head the Electrotechnical equipment). The scheme with blocking provides turning on of the pump only if the engine works. The fact that the engine works the relay receives information from the control unit. The scheme with blocking should not allow ignitions because of leak of gasoline as a result of accident.

Here it is checked whether gasoline gives the fuel pump. For this purpose the recirculation hose (2) is disconnected in a junction. Put on a hose the giving fuel-supply line (1) and lower it in capacity.

Six-cylinder engine:

1 – recirculation pipeline;
2 – the giving fuel-supply line;
3 – fuel pressure regulator.

Search of malfunctions in the fuel pump with the electric drive

First of all check a safety lock (the head the Electrotechnical equipment). If it as it should be:


  1. Sometimes by listening it is possible to obtain information whether the pump works: listen under the car at height of the fuel tank whether the pump when your assistant includes ignition turns on for a short time.
  2. If the sound of operation of the pump, then probably it as it should be is heard. If you hear nothing, then check whether fuel moves:
  3. Dismantle the giving or recirculation fuel pipe and lower it in capacity.
  4. Even at the idle engine a little fuel as in fuel system there is certain residual pressure has to act.
  5. If is not present, a way your assistant will put a starter in action.
  6. Now the fuel pump has to give fuel.
  7. If there is no it, then it is necessary to check the mnogoshtyrkovy socket above on a deaf flange of the fuel tank whether current to the pump arrives in general:
  8. Cast away a floor covering of a luggage carrier.
  9. Unscrew a black cover.
  10. Disconnect the mnogoshtyrkovy socket.
  11. The voltmeter or control lamp check whether there is voltage about 12 V between contacts of the socket 1 and 4 (a brown and green/yellow wire). To take measurement, your assistant has to put a starter in action (the gear shifting lever in neutral situation, is switched on the emergency brake).
  12. If, despite the correct tension, the pump does not work, it is faulty – dismantle and replace it.
  13. If there is no tension, perhaps, the relay is faulty. About its check see in the head the Electrotechnical equipment.
  14. Among other sources of malfunctions it is necessary to call: defect in a wire to the relay or to the pump, got littered or will bend a fuel pipe, the main filter got littered.