Warning: Before disconnecting any electrical wiring (including high voltage) from the ignition system, the ignition must be switched off. If this precaution is not observed, there is a risk of damage to the integrated circuit components and electric shock.
Self-monitoring system
1. The control unit is equipped with a fault memory that functions when the ignition is on. Damage information is stored in permanent memory, which must be cleared after the damage is corrected. Other damages are stored in an additional memory that is not reset after the ignition is turned off, but is automatically updated when the engine is turned on.
2. The following paragraphs describe the method for reading fault data using a diode tester. Audi dealers use a special electronic damage reader, but this is not usually available to a home mechanic.
3. Prepare the diode tester and wiring, draw up a test circuit as shown in fig. 4.11.
4. Check the fuses 13, 21, 27 and 28. Turn off the air conditioner and check the cylinder head earth wire is secure.
5. Start the engine, drive the car for at least five minutes. During this time, the engine speed must exceed 3000 rpm, to do this, fully depress the accelerator pedal several times for a short time.
6. Start the engine at idle speed. Do not increase engine speed during the following tests. The engine must be warmed up to normal operating temperature.
7. If the engine does not start from the starter within six seconds, leave the ignition on.
8. Locate the two test connectors on the driver's front leg area and connect the wiring as shown.
9. Connect the connector and sockets C and D together for at least four seconds.
10. Disconnect the connector and socket, then count the number of flashes of the diode tester. The sequence begins with a signal lit for 2.5 seconds and a pause lasting 2.5 seconds, then pulses are given after 0.5 seconds. Count the number of each group of signals. The result will be a four-digit number. If no damage is found, code 4444 will be issued (four groups of four flashes).
11. Check if there is still damage by repeating the procedure from point 9.
12. Further testing of the KE-Motronic system is described in Section 3.
13. Decoding of damage codes for the engine ZA is given in the following table.
- 1111 Control unit
- 2113 Engine speed signal, air flow meter plate stuck, Hall sensor defective
- 2121 Switch I idle throttle
- 2123 Switch II wide open throttle
- 2141 Detonation control at the limit
- 2142 knock sensor
- 2231 Limits for setting excessive idle stabilization
- 2232 Air flow meter potentiometer
- 2312 coolant temperature sensor
- 2341 Lambda control at the limit
- 2342 Lambda control
- 2343 The limit of the mixture composition control unit, lean
- 2344 The limit of the mixture control unit, rich
- 4431 idle speed control valve
- 4444 No damage
- 0000 End of fault indication
14. Testing of individual parts is given in the following paragraphs. Before removing any part, check the wiring associated with it. Note that incorrect ignition timing can cause the knock sensor to reach its control limit and cause a corresponding fault indication. After reading the damage from the permanent memory, the memory must be cleared, as described in paragraphs 28-32. The main memory will be cleared when the engine is started.
Ignition coil
15. Be guided Chapter 6, paragraphs 1-4.
Control block
16. If the self-monitoring procedure shows damage in the control unit, it must be replaced.
Hall Sensor
17. Be guided Chapter 8, paragraphs 21-28.
Power output block
18. First check the ignition coil as described in Chapter 6.
19. Squeeze the spring clip together and disconnect the wire connector from the connector of the power output unit behind the ignition coil.
20. Turn on the ignition, then connect the digital multimeter (switch to voltage measurement mode) between two outer clamps (1 and 3) on the socket. If the meter does not show battery voltage, check the wiring.
21. Connect a diode tester between terminals 2 and 3 on the connector.
22. Quickly rotate the engine with a starter, check the LED glow. If the diode does not light up, check the Hall sensor.
23. Turn off the ignition, reconnect the connector.
24. Disconnect the wire contact from the Hall sensor on the distributor.
25. Connect the digital multimeter between terminals 1 (-) and 15 (+) on the ignition coil, then turn on the ignition.
26. Using a piece of wire, connect the center terminal of the Hall sensor wire to ground. The voltage should first increase to 2 volts, then drop to zero within 1-2 seconds.
27. If the voltage does not drop, install a new power output unit or control unit, and also check for leakage of sealant from the ignition coil. If necessary, replace the ignition coil.
Damage permanent memory - reset
28. Connect the special test cable as shown in fig. 4.11. The ignition must be off.
29. Connect the connector and socket C and D.
30. Turn on the ignition, the LED should light up.
31. Disconnect the connector and socket C and D for at least four seconds, the code - 0000 should be displayed.
32. Reconnect the connector and socket within five seconds, then disconnect them, the LED should be solid.
Visitor comments