BMW 1999-2005 M3 Service Manual page 316

Ignition System
3 of 10
http://ebahn.bentleypublishers.com/BMW/3/E46/Repair%20Manuals/1...
Unfasten screws (B) and remove
lower microfilter housing.
Remove plastic engine cover from
-
top of valve cover by prying off bolt
covers and removing cover
mounting bolts.
Disconnect harness connector from coil.
Connect multimeter between terminal
15 (+) in connector and ground.
Turn ignition on and check for
-
battery voltage.
If battery voltage is not present,
check wire between terminal 15
and ignition switch. See Electrical
Wiring Diagrams.
CAUTION!
The wiring to terminal 15 (+) of the
coil (via the ignition switch) is not
fuse protected. Use care when testing
this circuit.
- Turn ignition off.
Remove coil and inspect coil housing
for hairline cracks or leaking casting
material. A leaky ignition coil may
indicate a faulty Engine Control Module
(ECM). Check ECM before installing a
new coil.
CAUTION!
Note location of coil ground straps
before coil removal; reinstall in the
same location.
Use a multimeter to test:
-
2/25/2009 9:54 PM