Page 1905 of 4323
± DIAGNOSTICSBODY CONTROL SYSTEM
DI±1703
1897 Author: Date:
2005 SEQUOIA (RM1146U)
3 Check wire harness and connector between body ECU and body ground, body
ECU and battery (See page IN±35).
NG Repair or replace wire harness or connector.
OK
Proceed to next circuit inspection shown in
problem symptoms table
(See page DI±1686).
Page 1906 of 4323
I18741
Body ECU
RWW R1
Rear Washer
Motor
C10
Rear
Wiper and
Washer
SwitchRWLS
RWC1 Y±B G±B L±O
L±O
WASH1
OFF
INT
ON
WASH2
J8 J/C1
2
IEIA14
B7
13
AG±B
G±B IL1
B5 10
6 25 10
12
7
2
W±B
WR EW C1R+1R
B5 DI±1704
± DIAGNOSTICSBODY CONTROL SYSTEM
1898 Author: Date:
2005 SEQUOIA (RM1146U)
Rear wiper switch and motor circuit
CIRCUIT DESCRIPTION
Body ECU judges the switch position with the terminal voltage of the rear wiper and washer switch and runs
the washer motor.
WIRING DIAGRAM
DI56X±09
Page 1907 of 4323
± DIAGNOSTICSBODY CONTROL SYSTEM
DI±1705
1899 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Check wiper and washer switch (See page BE±49).
NG Replace wiper and washer switch.
OK
2 Check rear washer motor (See page BE±49).
NG Replace rear washer motor.
OK
3 Check wire harness and connector between wiper and washer switch and body
ECU, wiper and washer switch and body ground (See page IN±35).
NG Repair or replace wire harness or connector.
OK
4 Check wire harness and connector between rear washer motor and washer
switch, rear washer motor and body ECU (See page IN±35).
NG Repair or replace wire harness or connector.
OK
Proceed to next circuit inspection shown in
problem symptoms table
(See page DI±1686).
Page 1908 of 4323

I24351
Body ECU
11 3
21 5
B 5W
1G TAILLIGHT Relay
To Taillight
F10
Fusible Link BlockLG
B7
ALTTRLY 2 1L
81
BatteryInstrument Panel J/B
LG
DDJ/9
J/C DI±1706
± DIAGNOSTICSBODY CONTROL SYSTEM
1900 Author: Date:
2005 SEQUOIA (RM1146U)
Taillight Relay Circuit
CIRCUIT DESCRIPTION
TAILLIGHT relay will be ºONº by operating the light control switch. The transistor which activates the tail light
relay has two sorts: one is activated by the light control switch for fail safe and the other is activated by CPU.
When the theft deterrent system is activated, it causes the transistor in the ECU to switch ON and OFF at
approximately 0.4 sec. intervals. This switches the TAILLIGHT relay ON and OFF, and thus flashing the tail-
lights (See the wiring diagram below).
In this condition, if any of the following operations is done, the transistor in the ECU goes OFF and the TAIL-
LIGHT relay switches OFF, and thus stopping the taillights flashing:
(1) Unlock the front LH or RH door with a 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
DI6QY±15
Page 1909 of 4323

± DIAGNOSTICSBODY CONTROL SYSTEM
DI±1707
1901 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
HINT:
When using the hand±held tester, start the inspection from step 1 and when not using the hand±held tester,
start from step 2.
1 Check TAILLIGHT relay using hand±held tester.
PREPARATION:
(a) Connect the hand±held tester to the DLC3.
(b) Turn the ignition switch ON.
CHECK:
According to the display on the tester, perform the ºACTIVE TESTº.
BODY ECU:
ItemTest DetailsDiagnostic Note
TAIL LIGHTTaillight ON/OFF±
OK:
The taillights turn on or off correctly when operating them through the hand±held tester.
OK Proceed to next circuit inspection shown in
problem symptoms table (See page DI±1686).
NG
2 Check TAILLIGHT relay (See page BE±27).
NG Replace TAILLIGHT relay.
OK
3 Check wire harness and connector between TAILLIGHT relay and body ECU, bat-
tery and TAILLIGHT relay (See page IN±35).
NG Repair or replace wire harness or connector.
OK
Proceed to next circuit inspection shown in
problem symptoms table
(See page DI±1686).
Page 1910 of 4323

I24144
Body ECU
MAINEngine Room J/B
HEAD Relay
Instrument Panel J/B
Battery
LG±R 2D
B12FL
R±W
12 532F
2G
2C
B7 1G 1JL
R±L
R±L
HRLY 8
6
1
6
1
2
(*1): w/ Daytime Running Light
(*2): w/o Daytime Running LightLG±R69 8 To Headlight RH To Headlight LH To DRL No.4 Relay To DIMMER Relay To DIMMER Relay
B 4
5 F10
FL Block(*2) (*2) (*1)
(*1)
(*1)
H±LP RH (*2)
DRL (*1)
H±LP LH (*2)
(*1) DI±1708
± DIAGNOSTICSBODY CONTROL SYSTEM
1902 Author: Date:
2005 SEQUOIA (RM1146U)
Headlight Relay Circuit
CIRCUIT DESCRIPTION
HEAD relay will be ºONº by operating the light control switch. The transistor which activates the HEAD relay
has two sorts: one is activated by the light control switch for fail safe and the other is activated by CPU. The
one that is activated by CPU prevents the headlight from turning off at the time of trouble with the other sys-
tem in the automatic operation circuit.
When the theft deterrent system is activated, it causes the transistor in the ECU to switch ON and OFF at
approximately 0.25 sec. intervals. This switches the HEAD relay ON and OFF, and thus flashing the head-
lights (See the wiring diagram below).
In this condition, if any of the following operations is done, the transistor in the ECU goes OFF and the HEAD
control relay switches OFF, and thus stopping the headlights flashing:
(1) Unlock the front LH or RH door with a 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
DI5VQ±14
Page 1911 of 4323

± DIAGNOSTICSBODY CONTROL SYSTEM
DI±1709
1903 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
HINT:
When using the hand±held tester, start the inspection from step 1 and when not using the hand±held tester,
start from step 2.
1 Check HEAD relay using hand±held tester.
PREPARATION:
(a) Connect the hand±held tester to the DLC3.
(b) Turn the ignition switch ON.
CHECK:
According to the display on the tester, perform the ºACTIVE TESTº.
BODY ECU:
ItemTest DetailsDiagnostic Note
HEAD LIGHTHeadlight relay ON/OFF±
OK:
The headlights turn on or off correctly when operating them through the hand±held tester.
OK Proceed to next circuit inspection shown in
problem symptoms table (See page DI±1686).
NG
2 Check HEAD relay (See page BE±27).
NG Replace HEAD relay.
OK
3 Check wire harness and connector between HEAD relay and body ECU, battery
and HEAD relay (See page IN±35).
NG Repair or replace wire harness or connector.
OK
Proceed to next circuit inspection shown in
problem symptoms table
(See page DI±1686).
Page 1912 of 4323
I28516
J5
J/CBody ECU
FFOG J50
J/C J3
J/C
5 Instrument Panel J/B
From DIMMER Relay (*1) FOG LIGHT Relay
FOG
1K7
1B9
1J10 1L1
3
1 2 D
D
D
1
2F2
Front Fog
Light RH
W±B
B 1
2P
W±B
EDIGALTF10
FL Block 8
5
B
BatteryR±W
C8 Combination Switch
Fog Light Switch
B613
G±B
10
LFG BFG 11 P
F1
Front Fog
Light LH
G±W (*1)
Y±R (*2) WP
A
(*1): w/ Daytime Running Light
(*2): w/o Daytime Running LightB
J2
J/C B
BW±B
J18
J/C W±B W±B
IL1
From Headlight (*2) 16
A DI±1710
± DIAGNOSTICSBODY CONTROL SYSTEM
1904 Author: Date:
2005 SEQUOIA (RM1146U)
Front fog light relay and switch circuit
CIRCUIT DESCRIPTION
The fog light switch is built into the combination switch.
Turning the fog light switch ON supplies power to terminal FFOG of the body ECU.
The fog lights come on when the FOG light relay is turned on.
WIRING DIAGRAM
DI6U4±14