1995 TOYOTA SUPRA key

Headlight Control Relay Circuit
CIRCUIT DESCRIPTION
When the theft deterrent system is activated, it causes the Tr in the ECU to switch on and off at approximately
0.2 sec. intervals. This switches the headlight control relay on and off, thus flashing the headlights (See the wir-
ing diagram below).
In this condition, if any of the following operations is done, the Tr in the ECU goes off and the headlight control
relay switches off, thus stopping the headlights flashing:
(1) The front LH or RH door is unlocked with a key.
(2) The ignition switch is turned to ACC or ON position.
(3) Approximately 1 minute elapses.
BE±136± BODY ELECTRICAL SYSTEMTHEFT DETERRENT AND DOOR LOCK CONTROL SYSTEM

Taillight Control Relay Circuit
CIRCUIT DESCRIPTION
When the theft deterrent system is activated, it causes the Tr in the ECU to switch on and off at approximately
0.2 sec. intervals. This switches the taillight control relay on and off, thus flashing the taillights (See the wiring
diagram below).
In this condition, if any of the following operations is done, the Tr in the ECU goes off and the taillight control
relay switches off, thus stopping the taillights flashing:
(1) The front LH or RH door is unlocked with a key.
(2) The ignition switch is turned to ACC or ON position.
(3) Approximately 1 minute elapses.
BE±138± BODY ELECTRICAL SYSTEMTHEFT DETERRENT AND DOOR LOCK CONTROL SYSTEM

Luggage Compartment Door Key Lock and Unlock Switch Circuit
CIRCUIT DESCRIPTION
The luggage compartment door key lock and unlock switch goes on when the back door key cylinder is turned
to the unlock side with the key.
BE±142± BODY ELECTRICAL SYSTEM
THEFT DETERRENT AND DOOR LOCK CONTROL SYSTEM

(See page IN±30).
(1) Remove deck trim rear cover.
(2) Turn ignition switch ON.
Repair or replace luggage compartment door
key lock and unlock switch.
Measure voltage between terminal 1 of luggage
compartment door key lock and unlock switch
connector and body ground, when the key si
turned to the unlock side and not turned.
Check and replace theft deterrent and door lock
ECU. *1.
Check harness and connector between theft deterrent and door lock ECU and
key unlock switch, key unlock switch and body ground (See page
IN±30).
Check voltage between terminal 1 of luggage compartment door key lock
and unlock switch connector and body ground.
Key operation
Turned to the unlock side.
Not turned
Voltage
0 V
Battery positive voltage
Check luggage compartment door key lock and unlock switch.
Key operation
Turned to the unlock side.
Not turned
Disconnect luggage compartment door key lock and
unlock switch connector.
Check continuity between terminals 1 and 2, when
the key si turned to the unlock side and not turned.
Continuity
12
Repair or replace harness or connector.
Check and replace theft deterrent
and door lock ECU.
INSPECTION PROCEDURE
*1: When there is a malfunction that the theft deterrent
system cannot be set, proceed to the next
numbered circuit inspection shown on the
matrix chart (See page Be±123).
± BODY ELECTRICAL SYSTEMBE±143THEFT DETERRENT AND DOOR LOCK CONTROL SYSTEM

Door Key Lock and Unlock Switch Circuit
CIRCUIT DESCRIPTION
The door key lock and unlock switch is built in the door key cylinder.
When the key is turned to the lock side, terminal 3 of the switch is grounded and when the key is turned to the
unlock side, terminal 1 of the switch is grounded.
BE±158± BODY ELECTRICAL SYSTEM
THEFT DETERRENT AND DOOR LOCK CONTROL SYSTEM

INSPECTION PROCEDURE
(See page BE±123).
(See page IN±30).
Check door key lock and unlock switch.
(1)Remove the door trim and service hole cover.
(2)Disconnect the door key lock and unlock switch
connector.
Check continuity between terminals 1, 2 and 3 of
door key lock and unlock switch connector, when
door key lock and unlock switch is turned to the lock
side, unlock side and not turned.
Switch position
Lock side
Unlock side
Terminal
Replace door key lock and unlock switch.
OFF
Proceed to next circuit inspection shown on
matrix chart (See page
BE±123).
Repair or replace harness or connector.
Check harness and connectors between ECU and switch, switch and body
ground (See page IN±30).
± BODY ELECTRICAL SYSTEMBE±159THEFT DETERRENT AND DOOR LOCK CONTROL SYSTEM

Key Unlock Warning Switch Circuit
CIRCUIT DESCRIPTION
The key unlock warning switch goes on when the ignition key is inserted in the key cylinder and goes off when
the ignition key is removed.
The ECU operates the key confinement prevention function while the key unlock warning switch is on.
BE±160± BODY ELECTRICAL SYSTEM
THEFT DETERRENT AND DOOR LOCK CONTROL SYSTEM

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INSPECTION PROCEDURE
(See page IN±30).
Check key unlock warning switch.
Check continuity between terminals 1 and 2 of key
unlock warning switch connector, when the key is
inserted to the key cylinder or removed.
Switch position
Terminal
Replace key unlock warning switch.
OFF (Key inserted)
Proceed to next circuit inspection shown on
matrix chart (See page
BE±123).
Repair or replace harness or connector.
Check harness and connectors between ECU and key unlock warning
switch, key unlock warning switch and body ground (See page IN±30).
Disconnect key unlock warning switch connector.
ON (Key inserted)
± BODY ELECTRICAL SYSTEMBE±161THEFT DETERRENT AND DOOR LOCK CONTROL SYSTEM