A02471
Engine ECU
IGT
IGF
Tr1
E4
E4
6
7
I6
I6
3
1
B--L
B--L
Igniter
Ignition Coil
To Spark Plug
Tr2
I7
I7 1
2
B--R
IC6 9
18
B
B
B
B
To Tachometer
To Check Connector
B--R
J13
J14
C
onnec
to
r
Junc
tion
C
A
B--R
B--R
B--R
6
7
Ignition Switch
W--R
2
2
30A
AM2
2
1
W
Battery
Engine
Room J/B
IIA
IC6
DI--24
--
DIAGNOSTICS
ENGINE (1RZ--E)
DTC 14 I gniti on Signal Circuit
CIRCUIT DESCRIPTION
The ECU determines the ignition timing, turns ON Tr1 at a predetermined angle (
˚
CA) before the desired
ignition timing and outputs an ignition signal (IGT) ”1” to the igniter.
Since the width of the IGT signal is constant, the dwell angle control circuit in the igniter determines the time
the control circuit starts primary current flow to the ignition coil based on the engine speed and ignition timing
one revolution ago, that is, the time the Tr2 turns ON.
When it reaches the ignition timing, the ECU turns Tr1 OFF and outputs the IGT signal ”0”.
This turns Tr2 OFF, interrupting the primary current flow and generating a high voltage in the secondary coil
which causes the spark plug to spark. Also, by the counter electromotive force generated when the primary
current is interrupted, the igniter sends an ignition confirmation signal (IGF) to the ECU.
The ECU stops fuel injection as a fail safe function when the IGF signal is not input the ECU.
DTC No.
Detection Item
Trouble Area
14
No IGF signal to ECU for 4 consecutive IGT signal
S
Open or short in IGF or IGT circuit from IIA to engine ECU
S
Igniter
S
Engine ECU
WIRING DIAGRAM
DI1HP--01
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Pages From Supplement
3RZ-F,3RZ-FE
