BMW 3 (E46). Manual - part 236
600-1
General
A brief description of the principal parts
of the electrical system is presented
here. Also covered here are basic
electrical system troubleshooting tips.
See also
121 Battery, Alternator,
Starter
.
Electrical test equipment
Many electrical tests described in this
manual call for measuring voltage,
current, or resistance using a digital
multimeter. Digital meters are preferred
for precise measurements and for
electronics work because they are
generally more accurate than analog
meters. An analog meter (swing-
needle) may draw enough current to
damage sensitive electronic
components.
An LED test light is a safe, inexpensive
tool that can be used to perform many
simple electrical tests that would
otherwise require a digital multimeter.
The LED indicates when voltage is
present between any two test-points in
a circuit.
The integrated safety, comfort, security
and handling systems on E46 cars are
designed with self-diagnostic
capabilities. The quickest way to
diagnose many problems is to start out
with a scan tool read out of Diagnostic
Trouble Codes (DTCs). See
OBD
On Board Diagnostics
at rear of
manual.
Special Tools