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
- System of ignition
   That provides ignition
   When there is an ignition of fuel and air mix?
   Different systems of ignition
   So there is an ignition spark
   Executive body
   Brain of system
   The signals coming to the control unit
   Adjustment of a detonation
   Be careful in the address with ignition
   Works on system of ignition
   Search of malfunctions in ignition
   Ignition distributor
   Knot of a high voltage
   Replacement of spark plugs
   Right choice of spark plugs
   Check of the moment of ignition
+ Lighting
+ Alarm equipment
+ Tools and devices
+ Heating and ventilation
+ body Details
+ Salon
Search of malfunctions
Technical characteristics



Search of malfunctions in ignition

The one who wants to reveal defect in ignition, has to act on system:

  • Whether there is in general an ignition spark, it becomes clear by simple check of tension.
  • Giving of current to system of ignition/injection is carried out through safety locks 28, 29, 32 or 34 (depending on engine model). At refusal of ignition check these safety locks (the head the Electrotechnical equipment).
  • Attentive visual control often finds the most widespread sources of malfunctions (wires, sockets, breakdowns of tension).
  • Only after it serially check the ignition coil(s), the Hall sensor, or the sensor of number of turns of the engine, or the ignition moment sensor.
  • If all this was unsuccessful, let in a workshop will interrogate the computer.

Switch off ignition, having taken out the socket on terminal cascades.

At the left: in the four-cylinder engine of 1,6 l the socket (2) is disconnected on the terminal cascade (3) near the coil of ignition (1).

On the right: in the four-cylinder turbo engine and in the six-cylinder engine both sockets (arrow) on the terminal cascade are disconnected.

Whether there is ignition tension?

 PERFORMANCE ORDER

  1. 74 kW engine: remove one of wires on a spark plug, unscrew a candle.
  2. Again connect a wire of a high voltage to a candle and put it on the engine block so that it had a reliable contact with the block. Even better, for ensuring conductivity to connect an auxiliary starting wire cut part of a candle to the engine.
  3. Let your assistant will turn the engine a starter.
  4. If on electrodes of a candle slip powerful sparks, tension of ignition is, i.e. the system of ignition works. But there can be wrong the main adjustment of the distributor.
  5. 92 kW engine: in principle that way of actions as at the 74 kW engine, but it is necessary to check (to be convinced that both coils) candles of the 1st and 2nd cylinders work.
  6. Leave candles of the 3rd and 4th cylinders established.
  7. 110 kW four-cylinder engine: unscrew the ignition coil, unscrew a candle.
  8. Again connect the coil and a candle and fix on the engine so that the candle had a contact with weight, and the movement of the engine could not shake it. It is reached, for example, as follows: the carving part of a candle is connected to the engine, providing conductivity, by means of the plug of an auxiliary wire for its start.
  9. For the rest the same actions, as at the 74 kW engine if it is necessary, repeat the same on other cylinders.
  10. Six-cylinder engines: In principle the same way of actions as at the 74 kW engine, but it is necessary to check (to be convinced that all three coils) candles of the 1, 2 and 3 cylinders work.
  11. For all engines: if there is no spark, repeat attempt with a candle of other cylinder. If still there are no sparks, check all system of ignition.

At the left: whether there is in general a spark in system of ignition. For the sake of reliability the candle has to be fixed on the engine by means of a starting wire for ensuring conductivity. Here it is not shown for the sake of presentation.

On the right: on the removed socket (2) it is checked concerning the weight (3), whether tension on the terminal cascade (1) moves.

Open distributor of ignition (here four-cylinder engine)

1 – Hall sensor;
2 – diaphragm rotor;

3 – Hall sensor socket.


The coil of ignition of the four-cylinder engine of 1,6 l is supplied with the correct designations of plugs

Visual check of system of ignition

 PERFORMANCE ORDER

  1. All wires and contacts of sockets are strongly connected to the ignition coil(s), the terminal cascade, the control unit of ignition/injection and to the distributor (74 kW)?
  2. Perhaps, in mnogoshtyrkovy sockets one shtyrkovy contact moved?
  3. Whether there are on wires obvious damages?
  4. Whether filling weight is squeezed out in the ignition coil? Perhaps, it is faulty at the expense of it?
  5. Whether is on the case of the coil of ignition of a crack or traces of burns from the slipping sparks?
  6. In addition check, whether wires of a high voltage are strongly fixed and whether there are no isolation damages. Modern systems of ignition at the expense of the high tension of ignition react to the jumping sparks and creeping currents more sensitively.
  7. Whether there are damages on an ignition distributor cover (74 kW)? Pay special attention to inside.
  8. Whether all knots of system of ignition pure and dry? Damp dirt promotes breakdowns of tension.

 Council: At the following measurements pay attention that measuring and control devices have to be connected and be switched-off only at the switched-off ignition. If the engine for check and carrying out measurements is repeatedly turned by a starter without start, it is previously necessary to disconnect sockets of wires on injection valves.

Whether as it should be giving of tension in system of ignition?

Along with an ignition system crash due to the lack of tension, its insufficient giving too can cause considerable violations in work of system!

 PERFORMANCE ORDER

  1. All safety locks as it should be?
  2. 74 kW engine: disconnect the socket on the terminal cascade of power near the ignition coil.
  3. Connect the measuring device to the disconnected socket between contact 1 (plug 15) and contact 3 (weight).
  4. Include ignition.
  5. The device has to show at least 11,5 Century.
  6. If it did not show existence of tension or too low at all, defect is covered in a wire to the ignition lock.
  7. 92 kW engine: uncover heads of the block of cylinders, disconnect the socket on the terminal cascade of power on a package of coils of ignition.
  8. Connect the measuring device to the disconnected socket of contact of a black/blue wire (it is average) and weight.
  9. Include ignition.
  10. The device has to show at least 11,5 Century.
  11. If it did not show existence of tension or too low at all, defect is covered in a wire to the ignition lock.
  12. 110 kW four-cylinder engine: uncover heads of the block of cylinders, disconnect the socket on one of ignition coils.
  13. Connect the measuring device to the disconnected socket of contact of a black/blue wire and to contact of a brown/yellow wire (weight). It nests of the socket 2 and 3.
  14. Include ignition.
  15. The device has to show at least 11,5 Century.
  16. If it did not show existence of tension or too low at all, defect is covered in a wire to the ignition lock.
  17. Six-cylinder engine: disconnect the white socket at the left on a back wall of a motive compartment (giving of tension to ignition coils), serially connect the measuring device between each of three entrances of the plug 15 (in the top part of the socket) and weight.
  18. Include ignition.
  19. The device has to show at least 11,5 Century.
  20. If it did not show existence of tension or too low at all, defect is covered in a wire to the ignition lock.
  21. For all engines: measure concerning weight duration - + on the control unit (a red wire on the 16-polar socket). Nominal size: accumulator tension.
  22. The same measurement on a black/white wire on the 16-polar socket of the control unit at the included ignition.
  23. There too the device has to show at least 11,5 Century.

Sources of malfunctions

  • The ignition lock is faulty (the head Instrumenty and devices).
  • There is no conductivity in wires between the ignition lock / in the central switching knot and in the central switching knot / coil(s) of ignition or in the central switching hub / control unit. Check wires and sockets on the electric circuit given in the management.

Check of the coil of ignition

Four-cylinder engine of 74 kW

 PERFORMANCE ORDER

  1. Visual control of the coil of ignition was already carried out.
  2. For check of resistance, having switched off ignition, disconnect all wires on the ignition coil. We take measurements of primary and secondary winding of the coil.
  3. Take measurements, having connected an exact ohmmeter between plugs of the coil of ignition 1/-and 15 / +.
  4. Nominal size: 0,5–1,5 Ohms.
  5. The following measurement becomes between the plug 15 and 4 (4 = a plug nest of a thick main wire of a high voltage).
  6. The device has to show 5–9 kOhm.
  7. If the called sizes are not received, replace the ignition coil.
  8. It is impossible to define short circuit between windings by these measurements. If, despite good results of measurement, suspicion nevertheless falls on the ignition coil, you have to check the dismantled coil in a workshop on repair of the automobile electrotechnical equipment.

Check of the terminal cascade of power

Four-cylinder engine of 74 kW

 PERFORMANCE ORDER

  1. Control check: disconnect sockets on the terminal cascade of power near the ignition coil.
  2. Connect the measuring device to the removed socket between contact 2 (control) and contact 3 (weight). Turn the engine a starter. The device has to show at least 2 Century.
  3. Check giving of tension for system of ignition as it was already described.
  4. Check the ignition coil.
  5. If in system of ignition there is no spark though after carrying out three called checks defects are not revealed, the source of malfunction has to be in the terminal cascade of power. In this case replace together the terminal cascade and the coil of ignition.

Check of the sensor of the Hall

Four-cylinder engine of 74 kW

 PERFORMANCE ORDER

  1. Disconnect all sockets on injection valves.
  2. Disconnect the socket on the terminal cascade of power near the ignition coil.
  3. Functioning check: unbend a rubber tip on the connected Hall sensor socket (sideways on the distributor – it is remote) in order that contacts were available to carrying out measurement behind.
  4. LED control lamp connect to the plug 1 (green/white) wire and 2 (a green/grey wire).
  5. Let your assistant will turn the engine a starter: the light-emitting diode has to flash, in this case the sensor of the Hall and a wire to it as it should be.
  6. If it did not start blinking, check the bringing wire: disconnect the socket from the Hall sensor, connect the voltmeter to the plug 1 (a green/white wire) and to the plug 3 (a green/violet wire) of the socket.
  7. Include ignition.
  8. Look at the measuring device: it has to show 4,5–5,5 Century.
  9. Now connect the voltmeter to the plug 2 (a green/grey wire) and to the plug 3 (a green/violet wire) of the socket.
  10. Include ignition. Look at the measuring device: it has to show 4,3–5,2 Century.
  11. Result: if the LED control lamp does not blink though tension indicators correct, the Hall sensor is faulty.
  12. Tension indicators not as it should be: there is no conductivity in a connecting wire of the control unit.

The terminal cascade of power (2) coils of ignition of the 110 kW turbo engine of 1,8 l is placed on the case of the air filter on the right in a motive compartment.

In drawings the arrangement of contacts of the quadripolar socket ("3" in the photo) and the five-polar socket is shown ("1" in the photo).


In the four-cylinder engine with a working volume of 1,8 l the sensor of the Hall settles down at the left on forward part of the engine. Here are visible:

1 – Hall sensor case;
2 – socket.


The sensor of the Hall (1) is in the six-cylinder engine behind on the left head of the block of cylinders (2).

Check of coils of ignition and terminal cascade of power

Engine of 92 kW

 PERFORMANCE ORDER

  1. Carry out a visual inspection as it is described above.
  2. Check giving of tension as it is described above.
  3. Disconnect all sockets on injection valves.
  4. Check entrance signals: disconnect sockets of coils of ignition / the terminal cascade of power. Connect a diode control lamp to one of external contacts of the socket and measure concerning weight.
  5. When scrolling the engine a starter the lamp has to flicker slowly.
  6. Take the same measurement on opposite contact of the socket. There the lamp too has to blink slowly.
  7. If the diode control device does not blink: defect in the bringing wire, the control unit or in one of control unit sensors. Replace all constructive knot.
  8. All measurements as it should be, but are not present an ignition spark: ignition coils / the terminal cascade of power are faulty.

Check of coils of ignition

Four-cylinder engine of 110 kW

 PERFORMANCE ORDER

  1. Disconnect all sockets on injection valves.
  2. In the beginning carry out an inspection of tension of ignition (it is described above).
  3. If there is no spark in one spark plug, check giving of tension in system of ignition (as it is described).
  4. If there is no spark in one spark plug, trade coil places: if defect moves with the coil, the reason in this coil.
  5. To be sure, trade places still of a spark plug to exclude a malfunction source.
  6. If replacement with places of coils did not yield result, disconnect the socket on the coil of ignition of the idle cylinder and measure tension in the socket.
  7. Connect a measuring wire to both external contacts of the trekhshtyrkovy socket of the coil of ignition.
  8. Include ignition, the voltmeter has to show 12 Century. If tension is not present, look for defect in a wire to plus and minus.
  9. Switch off ignition.
  10. Check of impulses: connect the indicator of existence of tension to contacts 2 and 3 sockets.
  11. Let your assistant will put a starter in action.
  12. The light-emitting diode has to flicker.
  13. If the diode indicator of tension does not blink: the bringing wire, the terminal cascade of power, the control unit or one of control unit sensors are faulty.
  14. Switch off ignition.

Check of the terminal cascade of power

Four-cylinder engine of 110 kW

 PERFORMANCE ORDER

  1. Disconnect sockets on all valves of injection.
  2. Disconnect the quadripolar socket on the terminal cascade of power (under a cover on the case of the air filter).
  3. Connect one wire of the LED indicator of tension to weight.
  4. Check 1: apply a free wire of the indicator of tension serially to contacts of the terminal cascade of power of a shtyrkovy conclusion 1, 2, 3 and 4.
  5. Every time your assistant scrolls thus the engine a starter.
  6. The LED indicator of tension has to flicker at all four measurements, in this case an output signal of the terminal cascade of power to ignition coils as it should be.
  7. Again connect the socket.
  8. Disconnect the five-polar socket on the terminal cascade of power.
  9. Check 2: this time apply a free wire of the indicator of tension to contacts of the disconnected socket 1, 2, 4 and 5, at this time your assistant every time turns the engine a starter.
  10. The LED indicator of tension has to flicker on all four contacts, in this case an entrance signal of the terminal cascade of power as it should be.
  11. Check 3: check, whether as it should be connection with weight at a shtyrkovy conclusion 3 five-polar sockets.
  12. Result: if at efficient connection with weight the entrance signal as it should be, but is not present an output signal, the terminal cascade of power is faulty.
  13. If at all there is no entrance signal, a cause of defect in the control unit (or in its sensors) or in the bringing wire.

Check of the sensor of the Hall

Four-cylinder engine of 1,8 l and six-cylinder engine

 PERFORMANCE ORDER

  1. Disconnect all sockets on injection valves.
  2. Unbend a rubber tip behind on the Hall sensor socket (the socket remains connected).
  3. Check the LED indicator of tension, whether there is tension between the socket plug 1 and 3 (on the socket of the plug are designated) at the included ignition (min of 4 V).
  4. If is not present, check the bringing wire.
  5. Connect the LED indicator of tension between the plug 2 and 3.
  6. Let your assistant will turn the engine a starter.
  7. The LED indicator of tension has to flicker slowly — the Hall sensor as it should be.

The terminal cascade of power (2) coils of ignition in the six-cylinder engine is on the case of the air filter on the right in a motive compartment.

In drawings the arrangement of contacts of the triple-pole socket ("1" in the photo) and the quadripolar socket is shown ("3" in the photo).

At electric check of a package of coils of ignition (the six-cylinder engine) measurements are taken, first, on opposite nests of a wire of a high voltage, secondly, on the triple-pole socket of the terminal cascade of power behind at the left on a wall of a motive compartment. Assembly situation is shown in the photo. Placement of sockets in drawing.

Shtyrkovy sockets behind in the middle of a motive compartment of the six-cylinder engine

1 – detonation sensor II (blue);
2 – heating and signal lambda probes (probe at the left, black);
3 – ignition coils (the bringing wire, white);

4 – sensor of the moment of ignition (black);
5 – sensor of number of turns of the engine (gray).


Arrangement of contacts of sockets of the sensor of number of turns of the engine and sensor of the moment of ignition.

Check of the coil of ignition

Six-cylinder engine

 PERFORMANCE ORDER

  1. A visual inspection of coils of ignition was already carried out.
  2. For check of resistance disconnect all wires of a high voltage on coils. We take measurements on a secondary winding of the coil.
  3. Take measurement an exact ohmmeter between nests of wires of ignition of the 1st and 6th cylinders (the 1st coil). Nominal size: 9–14 kOhm.
  4. Repeat the same measurement between nests of wires of ignition of the 2nd and 4th cylinders (the 2nd coil), and also between nests of wires of ignition of the 3rd and 5th cylinders (the 3rd coil).
  5. If everything is all right, the secondary winding of coils is measured.
  6. Disconnect the white shtyrkovy socket on a back wall of a motive compartment (giving of tension on ignition coils), connect the measuring device on a choice to one of three sockets of the plug 15 (in the top part of the shtekerny socket).
  7. Disconnect the triple-pole socket on the terminal cascade of power (under a cover of the air filter), connect the second wire of measuring devices serially to all three plugs in the socket.
  8. Nominal size: at all three measurements of 0,5-1,0 Ohms.
  9. If the specified sizes are not received, replace a package of coils of ignition.

Check of the terminal cascade of power

Six-cylinder engine

 PERFORMANCE ORDER

  1. Disconnect sockets of all six valves of injection.
  2. Disconnect the triple-pole socket on the terminal cascade of power (under a cover of the air filter).
  3. Connect one wire of the LED indicator of tension to weight.
  4. Check 1: apply a free wire of the indicator of tension serially to contacts of a shtyrkovy conclusion 1, 2 and 3 terminal cascades of power.
  5. Every time your assistant scrolls thus the engine a starter.
  6. The LED indicator of tension has to flicker at all three measurements, in this case an output signal of the terminal cascade of power to ignition coils as it should be.
  7. Again connect the socket.
  8. Disconnect the quadripolar socket on the terminal cascade of power.
  9. Check 2: apply serially free wire of the indicator of tension to contacts of the disconnected socket 1, 2 and 4, in it time your assistant every time turns the engine a starter.
  10. The LED indicator of tension has to flicker on all four contacts, in this case an entrance signal of the terminal cascade of power as it should be.
  11. Check 3: check, whether as it should be connection with weight at a shtyrkovy conclusion 2 quadripolar sockets.
  12. Result: if at efficient connection with weight the entrance signal as it should be, but is not present an output signal, the terminal cascade of power is faulty.
  13. If at all there is no entrance signal, a cause of defect in the control unit (or in its sensors) or in the bringing wire.

Check of the sensor of number of turns of the engine

Six-cylinder engine

The sensor of number of turns of the engine is located on a gear wreath of a flywheel. Shtyrkovy connection of its wire is taken away to an arm up on a back wall of a motive compartment therefore measurement does not need to be taken under the car.

 PERFORMANCE ORDER

  1. Track laying of a wire from the sensor to an arm on a back wall of a motive compartment, check shtekerny sockets and a wire.
  2. Electric check by an exact ohmmeter:
  3. Disconnect the gray triple-pole shtyrkovy socket and connect an ohmmeter to a sensor wire between contact 1 and 2.
  4. The ohmmeter has to show about 1 kOhm, otherwise the sensor is faulty.
  5. The third contact is a shielding wire.
  6. For check of shielding connect an ohmmeter between contact 1 and 3 now, and then to contact 2 and 3.
  7. The ohmmeter has to show u of Ohms, otherwise the sensor is faulty.

Check of the sensor of the moment of ignition

Six-cylinder engine

 Councils: Other check consists in unscrewing of the sensor and cleaning of its front party. It is necessary to pay attention: never unscrew a sensor arm, but only the sensor.

The sensor of the moment of ignition is installed at the left behind directly on the case case. It is checked on the black triple-pole shtekerny socket in an arm on a back wall of a motive compartment.

Direct check is identical to how it becomes on the sensor of number of turns of the engine. It is not necessary to clean the front party only.

Check of the control unit

For check of the control unit of system of ignition/injection there are no methods in traditional understanding. But defect is found in a workshop by reading of the computer which is memorable malfunctions.

Detonation sensor

The detonation sensor (since their 1,8-liter engine it is put two) is checked by poll of the computer. Other opportunities for check are not present. Sometimes the defective sensor of a detonation draws to itself attention with an intensive ring in the engine at acceleration. At installation of a new sensor of a detonation surely consider the correct moment of an inhaling of a fixing bolt in 20 Nanometers.