Audi A3 1997 - 3 Self-Diagnosis of Dash Panel Insert with Long Life Service as of Model Year 2000; General Information

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-> Display on VAS 5051:
- Switch on ignition.
- From list -1- select appropriate vehicle system.
- Interrogate and erase fault memory of control unit just connected.
- Touch ◂ key.
- From list -1- select diagnosis function "06 - End of output".
- Switch ignition off and on again.
- Leave ignition switched on for 10 seconds. Then use fault reader to read out fault memory of control unit
just connected.
- If fault "Drive train data bus defective" is read out, replace control unit just connected.
- If fault "Drive train data bus defective" is not read out, connect next control unit and repeat sequence.
4 - Immobilizer self-diagnosis - immobilizer I (fixed code)
4.1 - Immobilizer self-diagnosis - immobilizer I (fixed code)
Note:
-> With immobilizer I with fixed code, the keys were originally not marked. Since the introduction of newer
immobilizers, the keys have been marked with a "W" and an "F". Keys for immobilizers II and III are only marked
with a "W".
4.2 - General information
Function
The electronic immobilizer consists of the following:
◆ Immobilizer control unit (integrated into dash panel insert electronics)
◆ Fault lamp in dash panel insert
◆ Reader coil at ignition lock and
◆ Matched ignition keys with electronics (transponder)
The electronic immobilizer control unit is an integral part of the dash panel insert, i.e. the dash panel insert has
to be replaced in the event of a defective control unit.
=> Electrical System; Repair Group 90
Immobilizer acts on engine-management system by way of an adapted engine control unit.
Reader coil for immobilizer reads response code of transponder each time ignition is switched on.
Audi A3 1997 ➤
Electrical system Self-diagnosis - Edition 02.2002
3.14 - Checking data exchange between control units 113