Subaru LEGACY 2002 Quick Reference Index page 88

Fuel Injection (Fuel System)
D: IGNITION SYSTEM CONTROL
! The ECM determines operating condition of the engine based on signals from the pressure sen-
sor, engine coolant temperature sensor, intake air temperature sensor, crankshaft position sensor
and other sources. It then selects the ignition timing most appropriate for the condition thus deter-
mined from those stored in its memory and outputs at that timing a primary current OFF signal to
the ignitor to initiate ignition.
! This control uses a quick-to-response learning feature by which the data stored in the ECM
memory is processed in comparison with information from various sensors and switches.
Thus, the ECM can always perform optimum ignition timing taking into account the output, fuel
!
consumption, exhaust gas, and other factors for every engine operating condition.
! Ignition control during start-up
Engine speed fluctuates during start of the engine, so the ECM cannot control the ignition timing.
During that period, the ignition timing is fixed at 10° BTDC by using the 10° signal from the crank-
shaft position sensor.
CONTROL SYSTEM
FU-30
Ignition coil and
ignitor assembly
B2H3827B