Toyota COMPUTER-CONTROLLED SYSTEM Training Manual page 95

ESA - IGF Signa l
IGF
(IGNITION
CONFIRMATION) SIGNAL
7 4
The counter-electromotive force that is whether ignition actually occurred or not .
generated when the primary current is This signal is used for diagnosis (See page 131)
interrupted causes this circuit to send an IGF and the fail-safe function (See page 145) .
signal to the ECU, which detects by this signa l
Ignitio n
coi l
Ignitio n
switc h
Battery
IGF signal II
generation
circui t
0
a IGT
-~
2
Ignition
. . r rnntrn l
circuit
II h I
I N ~
I- >
OHP 6 1
~ NOTE
In some recent models, the IGF signal is generated according to the primary current value . In these
models, IGF is switched on when IGT is on, and IGF is switched off when the primary current exceeds the
predetermined value .
FOR RECENT MODEL S
ON
IGT OF
F
Primary
------~ -
current
0
IGF O
N
OFF
IG F
-
FOR PREVIOUS MODEL S
IGT
ON
OFF ~
I
*
Primary
12 V
voltage
0
ON
IGF
OF F
* The counter-electromotive forc e
Igniter Engine ECU
84