Electronic Ignition; Ignition Coils; Ignition Control - Isuzu 2000 Trooper Workshop Manual

6E–572
TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Electronic Ignition

The electronic ignition system controls fuel combustion
by providing a spark to ignite the compressed air/fuel
mixture at the correct time. To provide optimum engine
performance, fuel economy, and control of exhaust
emissions, the PCM controls the spark advance of the
ignition system. Electronic ignition has the following
advantages over a mechanical distributor system:
D No moving parts.
D Less maintenance.
D Remote mounting capability.
D No mechanical load on the engine.
D More coil cooldown time between firing events.
D Elimination of mechanical timing adjustments.
D Increased available ignition coil saturation time.

Ignition Coils

A separate coil-at-plug module is located at each spark
plug. The coil-at-plug module is attached to the engine
with two screws. It is installed directly to the spark plug by
an electrical contact inside a rubber boot. A three-way
connector provides 12-volt primary supply from the
15-amp ignition fuse, a ground-switching trigger line from
the PCM, and a ground.

Ignition Control

The ignition control (IC) spark timing is the PCM's method
of controlling the spark advance and the ignition dwell.
The IC spark advance and the ignition dwell are
calculated by the PCM using the following inputs:
D Engine speed.
D Crankshaft position (58X reference).
D Camshaft position (CMP) sensor.
D Engine coolant temperature (ECT) sensor.
D Throttle position (TP) sensor.
D ION sensing module.
D Park/Neutral position (PRNDL input).
D Vehicle speed (vehicle speed sensor).
D PCM and ignition system supply voltage.
0013
D The crankshaft positron (CKP) sensor sends the
PCM a 58X signal related to the exact position of the
crankshaft.
060RY00022