Ignition Coil Assembly, Testing And Replacing - BMW 1999-2005 M3 Service Manual

Ignition System
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(ECM) or the ignition coils may result.
Note:
Spark plug replacement is covered in
020 Maintenance.
Checking for spark is difficult on
engines with distributorless ignition
systems.
Try removing the spark plugs and
inspecting for differences between
them. A poor-firing plug may be wet
with fuel and/or black and sooty, but not
always. If a coil is not operating, the
engine management system will
electrically disable the fuel injector to
that cylinder. The key is to look for
differences between cylinders.
Ignition coil assembly, testing
and replacing
CAUTION!
Use a digital multimeter for the
following tests.
Remove interior ventilation microfilter.
Remove housing for microfilter for
interior ventilation.
Open wiring harness loom (A) and
remove wires.
2/25/2009 9:54 PM