Subaru LEGACY 2002 Quick Reference Index page 214

Fuel Injection (Fuel System)
! The ECM receives two types of crank angle signal pulse; one is generated every 10° of crank-
shaft rotation and the other, every 30° of crankshaft rotation. Using these two types of signal pulse,
the ECM determines the position of each piston as follows:
The ECM interprets the pulses of range (A) shown below as the No. 1 and No. 2 cylinder pistons
being at TDC, the pulses of range (B) as the No. 5 and No. 6 cylinder pistons being at TDC, and
the pulses of range (C) as the No. 3 and No. 4 cylinder pistons being at TDC.
! The ECM outputs an ignition signal for the No. 1, No. 3 or No. 5 cylinder when it receives a cam-
shaft angle pulse before a TDC signal and for the No. 2, No. 4 or No. 6 cylinder when it receives
no camshaft angle pulse before a TDC signal.
(1)
(2)
(3)
#1
#6
(4)
#3
#2
#5
#4
(1) Cylinder number (TDC)
(2) Crank angle pulse
(3) Cam angle pulse
(4) Ignition timing
CONTROL SYSTEM
#5,6 #4,3 #1,2 #6,5
(A) (B)
#3,4 #2,1 #5,6 #4,3
(C) (A) (B) (C)
FU-34
#1,2 #6,5 #3,4 #2,1
B2H3914B