BMW M3 2001, Manual

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Self-diagnostics
All of the important electrical and elec-
tronic systems in the vehicle are tested
regularly and automatically – the driver
does not have to perform any extra
operations or adjustments.
The indicator lamps also come on
briefly after the ignition has been turned
on.
In the same manner, the electrical
resistance of the airbag ignition genera-
tors and all of the remaining airbag
components are constantly being
measured. Any fault in this system
would be detected immediately by a
current fluctuation that would neces-
sarily accompany it. The fault would be
indicated immediately by the airbag
warning lamp.
Even after you shut off the engine, the
overall functional status of your vehicle
is monitored. For example, all of the
flaps of the heating and ventilation
system travel to the nearest limit posi-
tion. This action ensures that the
defrost function will be preserved,
regardless of the circumstances, even
if, for example, a malfunction in the
heating or ventilation system should
occur during the night while the vehicle
is parked.
A calibration cycle runs every tenth time
the engine is shut off. During this cycle,
the actuator motors of all the heating
and ventilation flaps travel to their limit
stops in both directions. The limit posi-
tions and the return travel paths are
checked in this manner in order to
ensure that appropriate adjustments for
the operating elements can be made at
any time.
You can hear the vent flaps of the
heating or ventilation system
performing their self-diagnostics
routine after turning off the ignition. All
of the other self-diagnostics functions
operate silently in the background.
Any possible faults detected during
these self-diagnostics can be read out
and corrected by your BMW center
during the next regularly scheduled
maintenance.