Ignition Circuit Malfunction - Toyota T100 1996 Service Manual

DTC P1300
CIRCUIT DESCRIPTION
The ECM determines the ignition timing, turns on Tr
tion 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 rpm and ignition timing
one revolution ago, that is, the time the Tr
When it reaches the ignition timing, the ECM turns Tr
off, interrupting the primary current flow and generating a high voltage in the secondary coil
This turns Tr
2
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 ECM. The ECM stops fuel
injection as a fail safe function when the IGF signal is not input to the ECM.
DTC No.
No IGF signal to ECM for 4 consecutive IGT signal during
P1300
engine running
WIRING DIAGRAM
8
W−R
IA3
2
R/B No.2
2
1996 TOYOTA T100 (RM449U)
DIAGNOSTICS

Ignition Circuit Malfunction

DTC Detecting Condition
W−R
8
IG Switch
14
7
B−R
IE1
1
Ignition
Coil
− ENGINE (3RZ−FE)
at a predetermined angle (°CA) before the desired igni-
1
turns on.
2
off and outputs the IGT signal "0".
1
S Open or short in IGF or IGT circuit from igniter to ECM
S Igniter
S ECM
B−R
To To
Spark plug Tachometer
4
2 5
B−W
Tr
Igniter
Trouble Area
3
20 23
2
B−L
E7 E7
2
3 17
1
B−Y
E7 E7
(M/T)(A/T)
DI−103
DI0U1−03
ECM
5 V
IGT
Tr
1
IGF
S00874