Ignition Coil Resistance - BMW 1999-2005 M3 Service Manual

Ignition System
4 of 10
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Coil primary resistance at coil
terminals
Spark plug connector resistance
Compare results to specification in
Table e.
Table e. Ignition coil resistance
Component Terminals Resistance
Coil primary 1 (-) and
15 (+)
Coil
secondary
Spark plug
connector
Bosch
Beru
Replace ignition coil or spark plug
-
connector if resistance readings do
not meet specifications.
Remove ignition coil to be tested.
Install BMW special tool 12 7 030
(A) on coil to be tested.
Connect ground jumper between
coil mounting point and engine
ground point (B).
Clip scope high pick-up lead (C)
around ignition lead.
Start engine.
approx. 0.8
N.A.
1 k 20%
1.8 k
20%
2/25/2009 9:54 PM