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
   Various systems of ignition
   Principle of work of ignition
   Executive body
   "Brain" of system
   Impulses for the control unit
   Regulation on a detonation
   Security measures during the work with system of ignition
   Repair of system of ignition
   Diagnostics of system of ignition
   Ignition distributor
   Sensor of detonation combustion
   Elements of a high voltage
   Replacement of spark plugs
   Spark plugs
   Check of the moment of ignition
+ Lighting
+ Signalling devices
+ Devices and auxiliary devices
+ Heating and ventilation
+ body Elements
+ Search of malfunctions
+ Specifications




Diagnostics of system of ignition

"Shutdown" of ignition by separation of plugs (arrow) on electronic switchboards of coils of ignition, at the left on the example of models with 4-and 5-cylinder engines, on the right on the example of the 6-cylinder engine.


On an illustration the package of coils of ignition of 6-cylinder engines at the removed protection of the engine is shown. Figures on high-voltage sockets specify to what what cylinder the wire should be conducted.


On an illustration check of system of ignition on sparking is shown. For safety the candle should be connected electrically to the engine by means of an auxiliary cable that here it is not shown for the sake of the best presentation.

In the photo the coil of ignition of the models equipped 4-and 5-cylinder engines with the correct designations of plugs is represented. Drawing shows an arrangement of contacts of the connecting plug at the electronic switchboard (important when checking).


Some models with 4-cylinder engines are equipped with similar transformers of a high voltage. The coil of ignition and the electronic switchboard are integrated here in one case. And in this case at connections the corresponding designations of plugs are specified, and plugs 1 and 15 become available only after opening of a small lid. On an illustration the triple-pole plug is also visible.

The electronic switchboard (shooter) of coils of ignition of the 6-cylinder engine is located at a back wall of a motor compartment. Drawing shows the scheme of an arrangement of contacts of the 4-polar plug. The arrangement of contacts of the 3-polar plug corresponds shown in drawing at the left above (4-and 5-cylinder engines).

Who wants to find malfunction in system of ignition, has to act systematically.

 PERFORMANCE ORDER

  1. Usual check of secondary tension it is possible to find out, whether the igniting spark is created in general.
  2. Supply with food of systems of ignition and injection passes through safety locks 13, 21, 25, 27, 28 and 32 (depending on engine type). At refusal of system of ignition it is necessary to check these safety locks (the head the Body electrical system).
  3. Exact visual check of system of ignition helps to find the most frequent causes of failures (faulty wires and plugs, electric breakdowns).
  4. Only now it is necessary to check one by one the ignition coil, the sensor of the Hall or the sensor of frequency of rotation or the sensor of the moment of ignition.
  5. If everything did not lead it to success, it is necessary to interrogate memory of the store of malfunctions (in a workshop).

Verification of secondary tension

Directly in the beginning we check, whether the system of ignition gives the igniting spark:

 PERFORMANCE ORDER

  1. To disconnect a high-voltage wire from a spark plug, to unscrew a candle.
  2. Again to put on a wire a candle and to put it on the block of cylinders so that it had a reliable contact with "weight" (case). Even better – create an electric chain, having connected to the engine a spark plug carving by means of an auxiliary cable for "prikurivaniye".
  3. Ask the assistant to turn the engine a starter.
  4. If there is a powerful spark overlapping on a candle electrode, so current in system of ignition is available. Perhaps, the main adjustment of ignition is incorrectly established (see appropriate section in this chapter).
  5. If sparking does not happen, repeat check with a candle of other cylinder. In case and there sparking is absent, it is necessary to check all system of ignition completely.

Visual check of system of ignition

 PERFORMANCE ORDER

    Whether
  1. all plugs and shtekerny contacts on the ignition coil, the control unit of electronic system of ignition or the control unit of ignition and injection and on the ignition distributor are densely fixed?
  2. Whether any contact in the multicontact plug departed?
  3. Whether filling weight flowed out from the ignition coil? In this case it probably is faulty.
  4. Whether is not present on the case of the coil of ignition of cracks or traces of a deposit from breakdowns of a spark?
  5. In addition check, whether the main cables and high-voltage wires are reliably soldered and whether their isolation is whole. Modern systems of ignition because of high secondary voltage are more sensitive to breakdowns of a spark and leakages of current.
  6. Whether there are damages on a distributor cover? Pay attention first of all to inside!
  7. Whether all details of system of ignition pure and dry? Damp dirt promotes emergence of electric breakdowns.

 Help: when carrying out the checks described below watch connecting and switching-off measuring and control devices only at the switched-off ignition.

Whether as it should be food of system of ignition?

Along with an ignition system crash because of the absent food too weak tension too can cause serious malfunctions in work! Therefore for check it is necessary to use the voltmeter.

 PERFORMANCE ORDER

  1. Whether as it should be safety locks?
  2. Models with 4-and 5-cylinder engines: to separate plugs on the electronic switchboard near the ignition coil.
  3. To connect the measuring device to the disconnected plug between contact 1 (plug 15) and contact 3 ("weight").
  4. To include ignition.
  5. Volmetr has to show at least 11,5 Century.
  6. If the device the reason in conducting to the ignition lock does not show absolutely any tension or too weak, so.
  7. The same can be told about the plug in the car equipped with the so-called transformer of a high voltage.
  8. Models with 4-cylinder engines: to carry out the same measurement at a black-blue wire of the control unit of system Motronic or Digifant.
  9. Models with the 5-cylinder engine: to carry out the same measurement at a black-blue wire of the control unit of completely electronic system of ignition.
  10. And in these parts the indicator has to make at least 11,5 Century.
  11. Models with the 6-cylinder engine: to separate shtekerny connection of white color at a back wall of a motor compartment (supply with power supply of coils of ignition), to connect the measuring device between each of three sockets of the plug 15 in the top part of shtekerny connection and "weight".
  12. To include ignition.
  13. Each measurement has to show at least 11,5 Century.
  14. If the device the reason in conducting to the ignition lock does not show absolutely any tension or too weak, so.
  15. To carry out the same measurement at a black-green cable of the control unit of MPI/MPFI system.
  16. And here the indicator has to make at least 11,5 Century.

Reasons of malfunctions

 PERFORMANCE ORDER

  1. Indispensable condition: the battery is charged, safety locks as it should be.
  2. The ignition lock is faulty (the head Pribory and auxiliary devices).
  3. Gap in conducting between the lock of ignition and the central switchboard and between the central switchboard and the coil(s) of ignition or between the central switchboard and the control unit. To check passing of wires and plugs on the basis of electroschemes.

Check of the coil of ignition

Models with 4-and 5-cylinder engines

 PERFORMANCE ORDER

  1. A visual inspection of the coil of ignition was already carried out.
  2. For check of resistance at the switched-off ignition to disconnect all wires from the ignition coil. We measure primary and secondary winding.
  3. To measure an exact ohmmeter resistance between plugs of the coil of ignition 1/-and 15 / +.
  4. Standard resistance: 0,5 – 1,5 Ohms.
  5. The following measurement between plugs 1/-and 4.
  6. Here the ohmmeter has to show 5 — 9 kOhm.
  7. If the called indicators are not reached, it is necessary to replace the ignition coil.
  8. It is impossible to define short circuit between windings by these measurements. Therefore if, despite the received good results, all of you equally consider the ignition coil as the reason of malfunctions, it is necessary to give the removed ignition coil to a workshop on autoelectrical systems for recheck.

Check of the electronic switchboard

Models with 4-and 5-cylinder engines

It is impossible to check only separately taken electronic switchboard close to the ignition coil for functioning. Therefore it is necessary to work as follows:

 PERFORMANCE ORDER

  1. Check of management: to separate plugs on the electronic switchboard near the ignition coil.
  2. To connect the voltmeter to sockets between contact 2 (management) and contact 3 ("weight").
  3. To turn the engine a starter.
  4. The voltmeter has to show at least 2 Century.
  5. To check supply of system of ignition with food according to already described scheme.
  6. To check the ignition coil, see the following section.
  7. If in system of ignition there is no sparking in spite of the fact that three called checks did not reveal any malfunctions, so the electronic switchboard is defective. In this case it is necessary to replace the electronic switchboard complete with the ignition coil.

Transformer of a high voltage

Models with the 4-cylinder engine

In some 4-cylinder models the coil of ignition and the electronic switchboard are assembled in one knot (a tranformator of a high voltage). Connections from plugs 1 and 15 of the coil of ignition are located under a protective cover. Connection on "weight" (case) passes directly through the case. On the image of action the arrangement corresponds to the ignition coil with the electronic switchboard.

Check of the transformer of a high voltage

 PERFORMANCE ORDER

  1. A visual inspection is carried already out.
  2. For check of resistance at the switched-off ignition to separate the trekhshtyrkovy plug and the main high-free wire of the transformer. We measure primary and secondary winding of an element with the coil.
  3. To measure resistance between plugs of the transformer of a high voltage 1/-and 15 / +.
  4. Standard indicator: 0,5–0,7 Ohms.
  5. The following measurement between plugs 15 and 4.
  6. Standard indicators: 3–4 kOhm.
  7. If the specified indicators are not reached, it is necessary to replace the transformer.
  8. By means of these measurements it is impossible to distinguish short circuit between windings. Therefore if, despite the received good results, all of you equally consider the transformer of a high voltage as the reason of malfunctions, it is necessary to give the removed transformer to a workshop on autoelectrical systems for recheck.
  9. For check of tension you will need the voltmeter, and also auxiliary cables with test probes.
  10. To attach a measuring cable to both external contacts of the trekhshtyrkovy plug of the transformer of a high voltage.
  11. To include ignition, the voltmeter has to show about 12 Century. If tension is absent, it is necessary to look for a rupture of a cable in positive or negative conducting.
  12. To switch off ignition.
  13. Check of impulses: to disconnect tips of wires from a vpryskny nozzle or from the starting fuel valve and from the holder of cables of vpryskny nozzles.
  14. To connect the LED voltmeter by means of auxiliary cables and test probes to contacts 2 and 3 plugs of the transformer.
  15. To ask the assistant to give a starter.
  16. Light-emitting diodes have to flicker. If is not present, so the reason in the sensor of the Hall or the control unit of system of injection of Mono-Motronic or Digifant is faulty.
  17. To switch off ignition.

Check of coils of ignition

Models with 6-cylinder engines

 PERFORMANCE ORDER

  1. A visual inspection of coils of ignition was already carried out.
  2. For check of resistance it is necessary to disconnect all high-voltage wires from ignition coils. We check a secondary winding of coils.
  3. To measure an exact ohmmeter resistance between nests of high-voltage wires of system of ignition of the first and sixth cylinders (the first coil).
  4. Standard indicator: 9 — 14 kOhm.
  5. To make the same measurement between nests of high-voltage wires of the second and fourth cylinders, and also nests of wires of the third and fifth cylinders (the second and third coils).
  6. If everything is all right, on turn check of a secondary winding of coils.
  7. To disconnect shtekerny connection of white color near a back wall of a motor compartment (power supply of coils of ignition), to connect the measuring device for choice to one of three contacts of the plug 15 in the top part of shtekerny connection.
  8. To separate the triple-pole plug of the electronic switchboard (also near a back wall of a motor compartment), to connect the second wire of an ohmmeter in turn to all three plugs in the plug.
  9. Standard indicator: at all three measurements 0,5 — 1,0 Ohms have to be received.
  10. If it not so, it is necessary to replace a package of coils of ignition.

Check of the electronic switchboard

Models with the 6-cylinder engine

 PERFORMANCE ORDER

  1. To remove plugs from all six vpryskny nozzles.
  2. To disconnect the 4-polar plug of the electronic switchboard (near a back wall of a motor compartment).
  3. To connect the LED voltmeter to "weight".
  4. To connect a free wire of the voltmeter in turn to contacts 1, 3 and 4 disconnected plugs.
  5. The assistant every time thus turns the engine a starter.
  6. The LED voltmeter has to flash at all three measurements, otherwise it is necessary to check management or to replace the electronic switchboard.

Check of the sensor of the Hall

Models with 4-and 5-cylinder engines

 PERFORMANCE ORDER

  1. To disconnect plugs of the electronic switchboard near the ignition coil.
  2. To pull together a rubber cap of the plug of the sensor of the Hall (sideways at the ignition distributor) at the connected plug – in order that contacts of the plug became available.
  3. To connect the voltmeter to the plug 2 (a violet wire) and 3 (a violet-brown wire) the plug.
  4. To include ignition and slowly to turn the engine a hand in order that the punched diaphragm (trigger) of the distributor was turned, entered the sensor of the Hall and left it.
  5. To watch the measuring device: it has to show 0 — 0,5 In if the diaphragm is out of the Hall sensor. When the diaphragm is in the Hall sensor, the indicator has to make at least 4 Century.
  6. If there are no impulses, so it is necessary to check power supply of the sensor of the Hall:
  7. To disconnect plugs from the distributor and to connect the voltmeter to both external contacts of the plug.
  8. To include ignition, the voltmeter has to show at least 9 Century now.
  9. Otherwise the control unit or conducting are faulty.

Check of the sensor of the Hall

Models with the 6-cylinder engine

Plug connections behind in the middle of a motor compartment at model with the 6-cylinder engine

1 – for heating right a lambda probe;
2 – for the ignition coil (the bringing conducting);
3 – for a signal a lambda probe (right a lambda probe; shtekerny connection is behind behind fixture);

4 – for the sensor of detonation combustion of I;
5 – for the sensor of frequency of rotation of a shaft of the engine;
6 – for the ignition moment sensor.


 PERFORMANCE ORDER

  1. To disconnect all plugs of vpryskny nozzles.
  2. To pull together a rubber cap of the plug behind the Hall sensor (the plug remains connected).
  3. To check the LED voltmeter existence of tension at the included ignition between plug plugs 1 and 3 (on the plug of the plug are designated).
  4. If there is no tension — to check conducting.
  5. To connect the LED voltmeter between plugs 2 and 3.
  6. To ask the assistant to turn the engine a starter.
  7. The LED voltmeter has to start blinking, in this case the Hall sensor as it should be.

 Help: at malfunction of the sensor of the Hall it is optional to change all distributor at all. The sensor of the Hall can be got separately.

Check of the sensor of frequency of rotation of a shaft of the engine

Models with 6-cylinder engines

In drawing the arrangement of contacts of the plug of the sensor of frequency of rotation of a shaft of the engine and the moment of ignition is shown.

The sensor of frequency of rotation is located over a gear wreath of a flywheel. Its shtekerny connection is directed to the holder of the plug on a back wall of a motor compartment so it is not necessary to take measurements under the car at all up.

 PERFORMANCE ORDER

  1. To check passing of a wire from the sensor to the holder on a back wall of a motor compartment, to check reliability of shtekerny connection and isolation on wires.
  2. Electric check with an exact ohmmeter.
  3. To disconnect black triple-pole shtekerny connection and to connect an ohmmeter to the sensor between contacts 1 and 2.
  4. The ohmmeter has to show 1 kOhm, otherwise the sensor is faulty.
  5. The third contact is a shielding of a cable.
  6. To connect an ohmmeter for shielding check now between contacts 1 and 3, and also between contacts 2 and 3.
  7. The ohmmeter has to show Ohm, otherwise the sensor is faulty.

 Help: further check is a removal of the sensor and cleaning of its face party. Dirt or oiling on this place disturb work. Consider: never remove the holder of the sensor, but only the sensor. If fastenings of the sensor were weakened, it needs to be regulated anew in a workshop the special tool.

Check of the sensor of the moment of ignition

Models with the 6-cylinder engine

The sensor of the moment of ignition is installed at the left behind directly in the block of cylinders. It is necessary to check it through gray triple-pole shtekerny connection on a back wall of a motor compartment.

Actually check is similar to check of the sensor of frequency of rotation of a shaft of the engine which is described in the previous section.

Check of the control unit

For the control unit (electronic system of ignition or system of ignition and injection) there is no method of check in usual sense of this word. However you can find a cause of defect after poll of memory of the store of malfunctions (undressed Regular servicing). The control unit of electronic system of ignition is located under the right covering of foot space of the forward passenger. For removal it is necessary to turn out fixing screws and to delay a covering down.