Toyota Celica Supra 1986 Service And Repair Manual page 645

BODY ELECTRICAL SYSTEM -Theft Deterrent System
BE-97
H INSPECTION OF LIGHT CONTROL RELAY CIRCUIT
Turn ignition switch off.
I
DIODE
INSPECT DIODE CONTINUITY Replace diode.
Is diode of head light control relay side No
and/ or taillight control rel ay side normal
?
(See page BE-14)
Yes
COMPUTER
Disconnect computer and inspect connector
on w ire harness side as follows.
INSPECT HEADLIGHT CONTROL RELAY
Open or short circuit in wire harness
CIRCUIT
between terminal 12 of computer and
Disconnect taillight control relay and No
terminal 1 of headlight control relay.
theft deterrent horn.
Is there battery voltage between terminal 12
and body ground?
Yes
INSPECT TAILLIGHT CONTROL RELAY
Open or short circuit in wire harness
CIRCUIT
between termi nal 12 o f computer and
Disconnect headlight control relay and
No
terminal 1 of taillight control relay.
theft deterrent horn.
Is there battery voltage between terminal
12 and body ground?
Yes
J Replace computer
·I