Toyota 3F-E Repair Manual Supplement page 99

FI-40
No.
Terminals
ISC4 — El
8 ISC1
Fusible
MAIN 0.85R
Link
Battery
ECU
1=1
DEMOOD
EEO
000C 200MODOC
Voltmeter
0
////i/////
Troubleshooting with Volt/Ohmmeter
EFI SYSTEM -
Trouble
No voltage
EFI Main Relay
Fuse
EFI 15A
There is no voltage between ECU terminals ISC1
• and El.
Check that there is voltage between ECU terminal + B
O
( +
+
+B B1
Check wiring between ECU terminal El and body
ground.
I
O00000
ODOODEO0D
• Check ISC valve.
• (See page FI-67)
F10312
Replace ISC
valve.
Try another ECU.
Condition
Ignition switch ON
(IG SW ON)
and body ground.
B1)
(IG SW ON)
OK
OK
BAD
OK
Check wiring between ECU and EFI
main relay.
OK
STD Voltage
V
10 — 14
ECU
ISC1
o
ISC2
o
ISC3
o
ISC4
+B
o +
B1
o
M REL
El
O
F12437
ISC4
BAD
Repair or replace.
BAD
Repair or replace.