Section 08 ENGINE MANAGEMENT (4-TEC)
Subsection 02 (COMPONENT INSPECTION AND ADJUSTMENT)
IGNITION COILS
1
R1503motr175A
1. Ignition coil
NOTE: The MPEM energizes the primary side of
each ignition coil individually. It can detect open
and short circuit in the primary winding but it does
not check the secondary winding.
Using the vehicle communication kit (VCK) with
the B.U.D.S. software, energize the ignition coil
from the Activation tab.
You should hear the spark occurring. In doubt, use
an inductive spark tester or a sealed tester - avail-
able from tool suppliers to prevent spark occur-
ring in the bilge. Otherwise, perform the following
checks.
An ignition coil with good resistance measure-
ment can still be faulty. Voltage leak can occur
at high voltage level which is not detectable with
an ohmmeter. Replacing the ignition coil may be
necessary as a test.
WARNING
Never make a spark test with spark plug re-
moved. Flammable vapors may be present
in the bilge and ignited which could cause an
explosion.
Voltage Test
WARNING
When disconnecting coil from spark plug, al-
ways disconnect coil from main harness first.
Never check for engine ignition spark from
an open coil and/or spark plug in the engine
compartment as spark may cause fuel vapor
to ignite.
Disconnect the connector from the ignition coil
and check the voltage supplied by the MPEM.
Install safety lanyard on the DESS post.
Check voltage between terminal 2 of ignition
coil connector on the wiring harness and battery
ground.
R1503motr196A
2
1
The voltage should be 12 V.
If 12 V is NOT read, check continuity of appropriate
circuit2-16(cylinder1),2-17(cylinder2)or2-18
(cylinder 3). If it tests good, try a new MPEM.
If 12 V is read, disconnect the ECM connector A
from the ECM and check the continuity of appro-
priate circuit 41 (cylinder 1), 1 (cylinder 2) or 29
(cylinder 3).
R1503motr190A
1
41 29
ECM CONNECTOR
436
smr2004-Complete Line Up
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