Service Manual

4.31
ELECTRONIC FUEL INJECTION
4
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 for PTO cylinder. 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 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 / 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
the coil 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).
Ignition Coil Resistance Readings
Test
Pin
Connection
Resistance
Primary
Between 1 & 2
Between 3 & 2
0.4 Ω
Secondary
Between
High Tension
Lead Ends
5 k Ω
Ignition Coil
= T
Ignition Coil Retaining Bolt Torque:
75 in. lbs. (8.5 Nm)
Measure Between
Connector Pins
0.4 Ω
Measure Between
End Caps
5 k Ω