Toyota Supra 1990 Manual page 241

EFI SYSTEM - Troubleshooting with Volt/Ohmmeter (7M-GTE)
FI-67
No.
Terminals Trouble
Condition STD Voltage
12 AIC - E1 No voltage
Ignition switch
Air conditioning ON
10 - 14 V
ON
ECU
To A/C
A/C
Amplifier
r
El
-
FI4925
ECU
CD
CD
There is no voltage between ECU terminals A/C and El.
(Air conditioning ON)
Voltmeter
~~~;;;~~
LYJ
®
Check that there is voltage between ECU terminal A/C and
body ground.
NO
~OK
FI3576
®
Check wiring between ECU terminal El and body
ground.
ECU
Voltmeter
lJ!1~~~~~
t
OK
t
BAD
I
Try another ECU.
I
Repair or replace.
Check that there is voltage between
I
amplifier terminal and body ground.
I
BAD
Repair or replace.
OK
FI3219
Check wiring between amplifier and
I
BAD
Repair or replace.
ECU terminal A/C.
I