Page 1961 of 4323
± DIAGNOSTICSBODY CONTROL SYSTEM
DI±1759
1953 Author: Date:
2005 SEQUOIA (RM1146U)
Illumination circuit
CIRCUIT DESCRIPTION
The body ECU and the back door ECU detect the condition of each door courtesy light switch.
FRONT COURTESY LIGHT SWITCH CONTROL:
The 2 front courtesy light switches are directly connected to the body ECU and back door ECU. If the courte-
sy light switch is turned on (a front door is opened), voltage applied to terminal ILE of the body ECU is
grounded inside the ECU and the step light, front courtesy light, etc. come on.
REAR COURTESY LIGHT SWITCH CONTROL:
The 2 rear courtesy light switches are directly connected to the body ECU and back door ECU via each cour-
tesy light. The rear courtesy light comes on when a rear door is opened.
DID9B±01
Page 1962 of 4323
I28523
Back Door ECU
Sub J/B No. 3 ILE
B118
BF18
BD29
WWWW
J30J/C
J29 FMInstrument Panel J/BBody ECU
1G6
1G5
1M10
1E3
1G13
1G14
1E81M6
1J5ILE B73
1F 10
1M7W
3C
3A3A
3D6 6
16 6I17
Ignition Key
Cylinder Light
12W
R
R6R
J48R
J/C
J49
BC1 LF R
D13 Door Courtesy
Light Rear RH
12
D17 Door Courtesy
Light Switch Rear RH2 1
W±B
BA161
2
2
IN1R
A AJ21
J/C R
R 1B±O
2 1 D8 Diode
(Interior Light No. 1)BC17
R±YR±YW±B RW±B W±BRRRW (*1)
W (*2)
W
R
12 S8 Step Light
V7 Vanity Light RH
V6 Vanity Light LH
R11 Rear Interior Light
(*4) (*3) To Dome Fuse
W±B
W±B
W
G±R(*2)
(*2)
(*2) 1
2
4
de f g bc aR
(*2)
3ON
DoorOFF R
R DI±1760
± DIAGNOSTICSBODY CONTROL SYSTEM
1954 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM
(*1): w/o Sliding Roof, RSE and RSA
(*2): w/ Sliding Roof, RSE or RSA
(*3): w/ Sliding Roof w/ RSE or RSA
(*4): w/ Sliding Roof w/o RSE and RSA
Page 1963 of 4323
I28526
de fg
bc a
D12 Door Courtesy
Light Rear LH
D9 Diode
(Interior Light No. 2)
2 11 2
W±B
R
BA1 7R±Y
R±Y
D16 Door Courtesy
Light Switch Rear LH
1W±B (*1) (*2)O4 O53 9Overhead Module
Personal Light
Rear Interior Light(*2)
(*1)
(*1)
(*1) (*1)ON
DoorOFF
O4 (*1) (*2)O4 O51 13 13
G±R
(*2) O5
10
A
J8
J/C
IEW
(*1) W±B
R
± DIAGNOSTICSBODY CONTROL SYSTEM
DI±1761
1955 Author: Date:
2005 SEQUOIA (RM1146U)
(*1): w/o Sliding Roof, RSE and RSA
(*2): w/ Sliding Roof, RSE or RSA
Page 1964 of 4323
DI±1762
± DIAGNOSTICSBODY CONTROL SYSTEM
1956 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 illumination (interior light) using hand±held tester.
PREPARATION:
(a) Connect the hand±held tester to the DLC3.
(b) Turn the ignition switch ON. (Do not start the engine.)
(c) Turn the light control switch OFF.
CHECK:
According to the display on the tester, perform the ºACTIVE TESTº.
BODY ECU:
ItemTest DetailsDiagnostic Note
ILLUMI OUTPUTIlluminated entry system ON/OFF±
OK:
The illumination (interior) lights 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 illumination light (interior light system) (See page BE±40).
NG Replace defective light.
OK
Page 1965 of 4323
± DIAGNOSTICSBODY CONTROL SYSTEM
DI±1763
1957 Author: Date:
2005 SEQUOIA (RM1146U)
3 Check wire harness and connector between each illumination light and body
ECU, each illumination light and back door ECU, each illumination light and bat-
tery (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 1966 of 4323
I24147
B7
HORN HORN Relay
2
1Body ECU
1
2D18
HR
HORN
B5 B±Y
6 C9
Horn SW
B54 F10
FL Block H8
Horn (low)
1
1 B B8
2H
7
2F5
3W±R W±R19
IA1
26
Battery H7
Horn (high)Engine Room J/B
B DI±1764
± DIAGNOSTICSBODY CONTROL SYSTEM
1958 Author: Date:
2005 SEQUOIA (RM1146U)
Horn circuit
CIRCUIT DESCRIPTION
The vehicle horn sounds when the horn switch is pressed. It also sounds as an alarm for the theft deterrent
system when the body ECU detects any alert condition.
WIRING DIAGRAM
DI94T±08
Page 1967 of 4323
± DIAGNOSTICSBODY CONTROL SYSTEM
DI±1765
1959 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 vehicle horn 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
VEHICLE HORNTurn vehicle horn sound ON/OFF±
OK:
The horn sounds or stops correctly when operating it through the hand±held tester.
OK Proceed to next circuit inspection shown in
problem symptoms table (See page DI±1686).
NG
2 Check horn (See page BE±145).
NG Replace horn.
OK
3 Check horn switch (See page BE±145).
NG Replace horn switch.
OK
Page 1968 of 4323
DI±1766
± DIAGNOSTICSBODY CONTROL SYSTEM
1960 Author: Date:
2005 SEQUOIA (RM1146U)
4 Check horn relay (See page BE±145).
NG Replace horn relay.
OK
5 Check wire harness and connector between horn and body ECU, body ECU and
horn switch (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).