immobilizer AUDI A8 1997 D2 / 1.G ATQ Engine Ignition System Checking Workshop Manual

28-1


Ignition system, checking

General notes on ignition system


The battery should only be disconnected and
reconnected when the ignition is turned off,
since otherwise the Engine Control Module
(ECM) can be damaged.
The Engine Control Module (ECM) is equipped
with an On Board Diagnostic (OBD)
For the electric components to work properly, a
voltage of at least 12.7 V is required.
It is possible that the control module will
recognize a malfunction and store a DTC during
some tests. After completing all tests and
repairs, DTC memory should therefore be
checked and erased if necessary.
If the engine only starts briefly and then turns
off again after troubleshooting, repair or
checking of the components, it may be that the
immobilizer is blocking the Engine Control
Module (ECM). DTC memory must then be
checked and if necessary, control module must
be adapted.
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