Page 905 of 1807
DI-614
- DIAGNOSTICSTHEFT DETERRENT SYSTEM
842 Author: Date:
1997 SUPRA (RM502U)
LSWPE (T13 21T7 4)GBWBDoor unlock detection switch ON (door opened).Below 1WLSWP e E (T13-21 e T7-4)G-B e W-BDoor unlock detection switch OFF (door closed).1MW or higher
L2E (T13 22T7 4)GYWBDoor key lock and unlock switch ºlockº position.Below 1WL2 e E (T13-22 e T7-4)G-Y e W-BDoor key lock and unlock switch OFF or ºunlockº position.1MW or higher
TA I L e E (T13-23 eT7-4)G-W e W-BLight control switch ºTAILº position.10 - 14 V
HORN e E (T13-24 eT7-4)L-R e W-BHorn switch OFF.10 - 14 V
SRLY e Ground
(T13-25 eGround)L-O e GroundIgnition switch is turned to ºSTº position.
(When park/neutral position switch ºPº position.)10 - 14 V
Page 906 of 1807

DI4X0-01
- DIAGNOSTICSTHEFT DETERRENT SYSTEM
DI-615
843 Author: Date:
1997 SUPRA (RM502U)
PROBLEM SYMPTOMS TABLE
Proceed to the reference page shown in the matrix chart below for each malfunction symptom and trouble-
shoot for each circuit.
HINT:
Troubleshooting of the theft deterrent system is based on the premise that the door lock control system is
operating normally. Accordingly, before troubleshooting the theft deterrent system, first make certain that
the door lock control system is operating normally.
Theft Deterrent System:
Details of ProblemInspecting Circuit *1See page
1. Indicator light circuitDI-617
2. Luggage compartment door key lock and unlock switch
circuitDI-633
The theft deterrent system cannot be set3. Luggage compartment door courtesy switch circuitDI-636
4. Door courtesy switch circuitDI-640
5. Engine hood courtesy switch circuitDI-642
The indicator light does not blink when system is setIndicator light circuitDI-617
When the system is set
When the back door is opened by a method other than the key
The system does not operate
Luggage compartment door courtesy switch circuitDI-636
When the system is set
When the engine hood is opened
The system does not operate
Engine hood courtesy switch circuitDI-642
While the system is in warning operation
Horns do not soundHorn relay circuitDI-621
While the system is in warning operation
Theft deterrent horn does not soundTheft deterrent horn circuitDI-623
While the system is in warning operation
Headlights do not flashHeadlight control relay circuitDI-626
While the system is in warning operation
Taillights do not flashTaillight control relay circuitDI-628
While the system is in warning operation
The starter cut is not cut offStarter relay circuitDI-619
When the system is set
It is not canceled when the ignition key is turned to ACC or ON
position
Ignition switch circuitDI-630
When the system is set
It still operates when the back door is opened with the keyLuggage compartment door key lock and unlock switch
circuitDI-633
System is still set even when a rear door is openDoor courtesy switch circuitDI-640
Even when the system is not set
Horns soundHorn relay circuitDI-621
Even when the system is not set
Theft deterrent horn soundsTheft deterrent horn circuitDI-623
Even when the system is not set
Headlights stay onHeadlight control relay circuitDI-626
Even when the system is not set
Taillights stay onTaillight control relay circuitDI-628
*1:
If numbers are given to the circuit proceed with troubleshooting in the order indicated by those numbers.
Page 907 of 1807

DI-616
- DIAGNOSTICSTHEFT DETERRENT SYSTEM
844 Author: Date:
1997 SUPRA (RM502U)
Door Lock System:
TroubleSuspect AreaSee page
Whole function of the door lock control system does not operate.
1. ECU Power Source Circuit
2. Actuator Power Source Circuit
3. Door Lock Motor Circuit
4. Theft Deterrent and Door Lock Control ECUDI-644
DI-647
DI-650
DI-623
All doors or some doors are not locked and unlocked with the
door lock control switch and key lock and unlock switch.
1. Door Lock Control Switch Circuit
2. Door key Lock and Unlock Switch Circuit
3. Door Lock Motor Circuit
4. Theft Deterrent and Door Lock Control ECUDI-653
DI-656
DI-650
DI-623
Doors cannot be locked with the door lock control switch. (Doors
lock and unlock normally with the key lock and unlock switch.)
1. Door Lock Control Switch Circuit
2. Key Unlock Warning Switch Circuit
3. Door Courtesy Switch Circuit
4. Theft Deterrent and Door Lock Control ECUDI-653
DI-658
DI-640
DI-623
Doors are not locked or unlocked with the door key lock and un-
lock switch. (Doors lock and unlock normally with the door lock
control switch.)1. Door Key Lock and Unlock Switch Circuit
2.Theft Deterrent and Door Lock Control ECUDI-656
DI-623
Key confinement prevention function does not operate. (Doors
lock and unlock normally with the door key lock and unlock
switch.)1. Key Unlock Warning Switch Circuit
2. Door Unlock Detection Switch CIrcuit
3. Theft Deterrent and Door Lock Control ECUDI-658
DI-638
DI-623
Page 908 of 1807
DI4X1-01
I02537
Indicator Light
(Telltale Light LH)Theft Deterrent and
Door Lock ECU
W-L
W-B9
12
IE
J/B No.1
1
1J
IET13
10 IND
18
- DIAGNOSTICSTHEFT DETERRENT SYSTEM
DI-617
845 Author: Date:
1997 SUPRA (RM502U)
CIRCUIT INSPECTION
Indicator Light Circuit
CIRCUIT DESCRIPTION
When the theft deterrent system is preparing to set, this circuit lights up the indicator light. When the system
has been set, it continually turns the indicator light on for 1 second and turns it off for 1 second, thus blinking
the indicator light.
WIRING DIAGRAM
Page 909 of 1807
I02538
10 (+)9 (-)
DI-618
- DIAGNOSTICSTHEFT DETERRENT SYSTEM
846 Author: Date:
1997 SUPRA (RM502U)
INSPECTION PROCEDURE
1 Check indicator light.
PREPARATION:
(a) Remove instrument panel cluster finish panel.
(b) Disconnect telltale light RH connector.
CHECK:
Connect positive lead to terminal 10 and negative lead to
terminal 9 of indicator light connector.
OK:
Indicator light comes on.
NG Replace telltale light RH.
OK
2 Check harness and connector between theft deterrent and door lock ECU and
indicator light, indicator light and body ground (See page IN-28).
NG Repair or replace harness or connector.
OK
Check and replace theft deterrent and door
lock ECU. *
1
*1:
When there is a malfunction that the theft deterrent system cannot be set, proceed to the next numbered
circuit inspection shown on matrix chart (See page DI-615).
Page 910 of 1807
N19900
1K
1J
IJ2P2P2
C9C9IJ1
EA122
2IB2IF2
I19I19IB1
2
2A
S2S3 4
6
87 B1365
1223
1
2
3510Theft Deterrent and
Door Lock ECU
EA2
EA3
4Starter Relay MAINL-OSRLY
25
Clutch Start Switch(M/T)
21AM2 J/B No.1 STR/B No.2
2
1
2JZ-GTE
2JZ-GE
Battery1
2 B
BL-O
L-O B-WB-WW-R
W-R W-B
B
B B 1 Ignition
SwitchT13
Park/Neutral Start Switch
1
1 B
(A/T)
12
- DIAGNOSTICSTHEFT DETERRENT SYSTEM
DI-619
847 Author: Date:
1997 SUPRA (RM502U)
Starter Relay Circuit
CIRCUIT DESCRIPTION
When the theft deterrent system is activated, contact ºaº in the ECU becomes open, creating an open circuit
in terminal ST circuit and making the starter inoperative (starter cut).
In this condition, if one of the following operations is done, the contact ºaº in the ECU is grounded, thus can-
celing the starter cut:
(1) The front LH and RH door is unlocked with a key.
WIRING DIAGRAM
DI4X2-01
Page 911 of 1807
I02540
START
Disconnect
SPLY (+)
DI-620
- DIAGNOSTICSTHEFT DETERRENT SYSTEM
848 Author: Date:
1997 SUPRA (RM502U)
INSPECTION PROCEDURE
HINT:
This troubleshooting is based on the premise that engine cranking occurs.
If the engine does not crank, proceed to the engine troubleshooting on page DI-3 or DI-141 (Vol. 1).
1 Check voltage between terminal SRLY of theft deterrent and door lock ECU con-
nector and body ground.
PREPARATION:
(a) Remove the instrument panel. (See page BO-50)
(b) Disconnect the ECU connector.
CHECK:
Measure voltage between terminal SRLY of theft deterrent ECU
connector and body ground, when ignition switch is turned to
ST position.
OK:
Voltage: 10 - 14 V
OK Check and replace theft deterrent ECU.
NG
Check and repair harness and connector between starter and theft deterrent and door lock ECU
(See page IN-28).
Page 912 of 1807
I02710
I02710
Theft Deterrent and
Door Lock ECU R/B No.2
HORN Relay
R/B No2.Horn Switch
HornL-R
L-B HAZ-HORN
BatteryHORN
L-BL-R
L-R W
22
2 2
2
2A 11
1116
14
L-R
L-B 3IB2IF2
24
BT13
- DIAGNOSTICSTHEFT DETERRENT SYSTEM
DI-621
849 Author: Date:
1997 SUPRA (RM502U)
Horn Relay Circuit
CIRCUIT DESCRIPTION
When the theft deterrent system is activated, it causes the Tr in the ECU to switch on and off in approximately
0.2 sec. cycles. This switches the horn relay on and off, thus the horn blow (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 horn relay
switches off, thus the horns stop blowing:
(1) The front LH or RH door is unlocked with a key.
(2) The ignition switch is turned to the ACC or ON position.
(3) Approximately 1 minute elapses.
WIRING DIAGRAM
DI4X3-01