4.34
ELECTRONIC FUEL INJECTION
IGNITION COIL
Operation Overview
The ignition coil is used to provide high voltage to fire the spark
plugs. When the ignition key is on, DC voltage is present in
primary side of the ignition coil windings. During engine
rotation, an AC pulse is created within the crankshaft position
sensor for each passing tooth on the flywheel. The two-tooth gap
creates an “interrupt” input signal, corresponding to specific
crankshaft position. This signal serves as a reference for the
control of ignition timing. The ECU then calculates the time
interval between the consecutive pulses, and determines when
to trigger the voltage spike that induces the voltage from the
primary to the secondary coil windings to fire the spark plugs.
Ignition Coil / HT Lead Replacement
1. Remove the driver and passenger seats.
2. Remove the rear service panel to access the ignition coil.
3. Disconnect the ignition coil harness and remove the high
tension leads from the coil.
4. Remove the fastener retaining the ignition coil and remove
it from the vehicle. If replacing the high tension lead(s),
remove the other end of the lead(s) from the spark plug.
5. Install the new ignition coil and/or high tension lead(s).
NOTE: Be sure to mark / note which ignition coil
wire goes to which cylinder and ignition coil post.
The engine will misfire if the spark plug wires are
installed incorrectly. The spark plug wires are
marked PTO and MAG and should be installed to the
corresponding cylinder spark plug and coil post.
Ignition Coil Tests
The ignition coil can be tested by using an ohm meter. Use the
following illustration and specification table to test the ignition
coil.
Primary Test
Secondary Test
Ignition Coil Retaining Bolt Torque:
75 in. lbs. (8.5 Nm)
Ignition CoilIgnition Coil
Ignition Coil Resistance Readings
Test Pin Connection Resistance
Primary
Between 1 & 2
Between 2 & 3
0.4
Secondary
Between High Tension
Lead End Caps
(Red end caps on coil end)
6.6 k
Measure Between
Connector Pins
0.4
Measure Between End Caps
6.6k