Toyota Celica Supra 1986 Service And Repair Manual page 626

BE-78
BODY ELECTRICAL SYSTEM - Cruise Control System
D
INSPECTION OF STOP LIGHT SWITCH CIRCUIT
Turn ignition switch on.
I
Is stop fuse normal
?
No
• Short circuit in wire harness between
terminal 8 of computer and fuse.
• Short
circuit in wire
harness between
terminal 9 of computer and fuse.
Yes
c
OMPUTER
Disconnect computer and inspect connector
on wire harness side as follows.
INSPECT RELEASE VALVE CIRCUIT
Yes
InSPect stop light switch.
Is there continuity between terminal 1 and
2 w ith brake pedal depressed
?
No
INSPECT STOP FUSE CIRCUIT
No
Open circuit in wire harness between
Is there battery voltage between terminal 9 and
terminal 9 of computer and STOP fuse.
body ground ?
Yes
INSPECT STOP LIGHT SWITCH CIRCUIT
No
Open or short circuit in wire harness
Is there battery voltage between terminal 8 and
between terminal 8 of computer and
body ground with brake pedal depressed
?
terminal 2 of stop light switch.
Yes
Replace computer.