Subaru LEGACY 2002 Quick Reference Index page 213

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-33
Fuel Injection (Fuel System)
Ignition coil and
ignitor assembly
B2H4153A