Page 402 of 1202
BE3841N14680I09775
SRLY
(+)(-) Disconnect START
- DIAGNOSTICSTHEFT DETERRENT SYSTEM
DI-227
1996 TERCEL (RM440U)
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 DI-1.
1 Check voltage between terminal SRLY of theft deterrent ECU connector and
body ground.
PREPARATION:
(a) Disconnect the theft deterrent ECU connector.
(b) Transmission in neutral position.
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 - 14V
OK Check and repair theft deterrent ECU.
NG
Check and repair harness and connector between starter and theft deterrent ECU
(See page IN-26).
Page 403 of 1202
N20819
Theft Deterrent ECU
SH T411
V-W IC2
4
V-W
1
2
W
Engine Room
Relay Block
MAIN FL
Battery 2
1
EA2BB
Theft Deterrent Horn
HAZ-HORN
W
T1 DI-228
- DIAGNOSTICSTHEFT DETERRENT SYSTEM
1996 TERCEL (RM440U)
Theft Deterrent Horn Circuit
CIRCUIT DESCRIPTION
When the theft deterrent system is activated, contact (a) and contact (b) in the ECU close alternately in cycles
of approximately 0.2 sec., causing the theft deterrent horn to blow (See the wiring diagram below).
In this condition, if any of the following operations is done, the contact (a) in the ECU opens, thus stopping
the theft deterrent horn from blowing:
(1) Unlock the front LH or RH door with key.
(2) Turn the ignition switch to ACC or ON position.
(3) Unlock the doors with the wireless door lock control system.
(4) Wait for approximately 60 seconds.
WIRING DIAGRAM
DI4N6-02
Page 406 of 1202
N20820
BatteryMAIN FL
B1
EA2 HAZ-HORN
2 W2Engine Room Relay Block
Horn Relay
11
2
2IC1G-Y24
T4
G-R
1
HORNTheft Deterrent ECU
HORN
H4 G-Y
B
- DIAGNOSTICSTHEFT DETERRENT SYSTEM
DI-231
1996 TERCEL (RM440U)
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
0.4 sec. cycles. This switches the horn relay on and off, thus the horns 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 stopping the horns from blowing:
(1) Unlock the front LH or RH door with key.
(2) Turn the ignition switch to ACC or ON position.
(3) Unlock the doors with the wireless door lock control system.
(4) Wait for approximately 60 seconds.
WIRING DIAGRAM
DI4N7-01
Page 408 of 1202

N20821
BatteryHeadlight
LHHeadlight
RH MAIN FL B 1
EA2
R
R-L2
2HEAD LH
HEAD RH2 B-R Engine Room Relay Block
Headlight Control Relay
2
2R-L
IC1
16
Light Control
Switch
(Combination
Switch)
13R-L R-L10
T4 Theft Deterrent ECU
HEAD
C12
- DIAGNOSTICSTHEFT DETERRENT SYSTEM
DI-233
1996 TERCEL (RM440U)
Headlight Control Relay Circuit
CIRCUIT DESCRIPTION
When the theft deterrent system is activated, it causes the Tr in the ECU for switch on and off at approximate-
ly 0.4 sec. cycles. This switches the headlight control relay on and off, thus flashing the headlights (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 headlight control
relay switches off, thus stopping the headlights flashing:
(1) Unlock the front LH or RH door with key.
(2) Turn the ignition switch to ACC or ON position.
(3) Unlock the doors with the wireless door lock control system.
(4) Wait for approximately 60 seconds.
WIRING DIAGRAM
DI4N8-02
Page 410 of 1202
N20822
Battery MAIN FL 1
F6 F7ALT B-R
Taillight
LH Taillight
RH 2
EA2B-R
G 1J1Instrument Panel Junction Block
Taillight Control Relay
TAIL4
1E
8
1L
G G LGTheft Deterrent ECU
23
T4 TAIL
1
B
- DIAGNOSTICSTHEFT DETERRENT SYSTEM
DI-235
1996 TERCEL (RM440U)
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
0.4 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) Unlock the front LH or RH door with key.
(2) Turn the ignition switch to ACC or ON position.
(3) Unlock the doors with the wireless door lock control system.
(4) Wait for approximately 60 seconds.
WIRING DIAGRAM
DI4N9-01
Page 412 of 1202
N20823
BatteryMAIN FL2
F61
F7B-R B
Fusible Link
Block2
EA2B-R 2 2AM1
W-G 2 1
1B
1J W-G2Ignition Switch
3
B-Y4
1BCIG & RAD1
1DGRTheft Deterrent ECU
8
T3
ACC
I10Instrument Panel
Junction Block
Instrument Panel
Junction BlockACC
AM1
ALT
- DIAGNOSTICSTHEFT DETERRENT SYSTEM
DI-237
1996 TERCEL (RM440U)
Ignition Switch Circuit
CIRCUIT DESCRIPTION
When the ignition switch is turned to the ACC position, battery positive voltage is applied to the terminal ACC
of the ECU. Also, if the ignition switch is turned to the ON position, battery positive voltage is applied to the
terminals ACC and IG of the ECU. When the battery positive voltage is applied to the terminal ACC of the
ECU while the theft deterrent system is activated, the warning stops. Furthermore, power supplied from the
terminals ACC and IG of the ECU is used as power for the door courtesy switch, and position switch, etc.
WIRING DIAGRAM
DI4NA-02
Page 413 of 1202
N12877N14677I09780
Instrument Panel Junction Block
CIG & RAD
BE4061I05896I09781
ON
IG
(+) (-)
Disconnect
DI-238
- DIAGNOSTICSTHEFT DETERRENT SYSTEM
1996 TERCEL (RM440U)
INSPECTION PROCEDURE
1 Check CIG / RAD fuses.
PREPARATION:
(a) Remove the fuse box cover.
(b) Remove CIG & RAD fuse from instrument panel junction
block.
CHECK:
Check continuity of CIG & RAD fuses.
OK:
Continuity
NG Check for short in all the harness and compo-
nents connected to the CIG & RAD fuse (See at-
tached wiring diagram).
OK
2 Check voltage between terminals ACC of theft deterrent ECU and body ground.
PREPARATION:
(a) Disconnect the theft deterrent ECU connectors.
(b) Turn ignition switch ON.
CHECK:
Measure voltage between terminals ACC of theft deterrent
ECU connector and body ground.
OK:
Voltage: 10 - 14 V
OK Check and replace theft deterrent ECU.
NG
Check and repair harness and connector between theft deterrent ECU and battery
(See page IN-26).
Page 417 of 1202

BE4061I05898I09782
ON
(+)
(-)
1
Connect
I05899BE4061
I09783
21
Disconnect
DI-242
- DIAGNOSTICSTHEFT DETERRENT SYSTEM
1996 TERCEL (RM440U)
INSPECTION PROCEDURE
1 Check voltage between terminal 1 of luggage compartment door key lock and
unlock switch connector and body ground.
PREPARATION:
(a) Remove luggage compartment door trim.
(b) Turn ignition switch ON.
CHECK:
Measure voltage between terminal 1 of luggage compartment
door key lock and unlock switch connector and body ground,
when the key is turned to the unlock side and not turned.
OK:
Key operationVoltage
Turned to the unlock side0 V
Not turnedBattery positive voltage
OK Check and replace theft deterrent ECU.*1
NG
2 Check luggage compartment door key lock and unlock switch.
PREPARATION:
Disconnect luggage compartment door key lock and unlock
switch connector.
CHECK:
Check continuity between terminals 1 and 2, when the key is
turned to the unlock side and not turned.
OK:
Key operationTester connectionSpecified condition
Turned to unlock side1 - 2Continuity
Not turned-No continuity
NG Repair or replace luggage compartment door
key lock and unlock switch.
OK