TOYOTA SEQUOIA 2001 Service Repair Manual

I21525
Free Pushed in
F16805
Wire Harness View:
S25
STP
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±769
963 Author: Date:
2005 SEQUOIA (RM1146U)
3 Inspect stop light switch assy.
PREPARATION:
Disconnect the stop light switch assy connector.
CHECK:
Check resistance between terminals 1 and 4 of the stop light
switch assy.
OK:
Switch conditionTester connectionSpecified condition
Switch pin free1 ± 4Below 1 W
Switch pin pushed in1 ± 410 kW or higher
NG Replace stop light switch assy.
OK
4 Inspect suspension control ECU.
PREPARATION:
Disconnect the ECU connector.
CHECK:
Measure the voltage between terminal S25±27 (STP) of the
suspension control ECU and body ground when the stop lamp
switch is ON and OFF.
OK:
Switch conditionSpecified condition
Brake pedal depressed (ON)10 to 14 V
Brake pedal released (OFF)Below 1 V
NG Repair or replace harness connector.
OK
Replace suspension control ECU
(See page IN±35).

F19447
Body ECUSuspension Control
ECU
ACTY20
B631
S25 DOOR R DI±770
± DIAGNOSTICSAIR SUSPENSION SYSTEM
964 Author: Date:
2005 SEQUOIA (RM1146U)
DTC C1783/83 Door Courtesy Switch Circuit
(Test Diagnosis)
CIRCUIT DESCRIPTION
The door courtesy light switch turns on when the door is opened and turns off when the door is closed.
The signal is sent from the body ECU and the back door ECU into the DOOR terminal of the suspension
control ECU when any door is open.
HINT:
This DTC is output only when the sensor signal check is done.
For courtesy light switch connection, see the system diagram on page DI±698.
DTC No.DTC Detecting ConditionTrouble Area
C1783/83Door courtesy light switch signal does not change.

Door courtesy light switch

Back door lock assy (Back door courtesy light switch)

Door courtesy light switch circuit

Body ECU

Back door ECU

Suspension control ECU
WIRING DIAGRAM
DIDEA±01

± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±771
965 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Inspect courtesy light switch.
CHECK:
Check that the open door warning light comes on when any door or back door is opened and goes off when
all the doors are closed.
OK:
Courtesy light operates normally.
NG Check open door warning light
(See page DI±1608).
OK

F16805
Suspension Control ECU:
DOORS25
I27700
Body ECU:
ACTYB6
DI±772
± DIAGNOSTICSAIR SUSPENSION SYSTEM
966 Author: Date:
2005 SEQUOIA (RM1146U)
2 Check harness and connector (Suspension control ECU ± Body ECU).
PREPARATION:
Disconnect the body ECU and suspension control ECU con-
nectors.
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
Tester connection
(Symbol)ConditionSpecified condition
B6±20 (ACTY) ±
S25±31 (DOOR)AlwaysBelow 1 W
B6±20 (ACTY) ±
Body groundAlways10 kW or higher
NG Repair or replace harness or connector.
OK

I27702
Body ECU Wire Harness View:
B6
ACTY
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±773
967 Author: Date:
2005 SEQUOIA (RM1146U)
3 Inspect body ECU (ACTY output).
PREPARATION:
Reconnect the body ECU and suspension control ECU connec-
tors.
CHECK:
Measure the voltage between terminal B6±20 (ACTY) of the
multiplex network body ECU and body ground when doors are
opened and closed.
OK:
Door conditionSpecified condition
Each door openedBelow 1.5 V
All doors closed10 to 14 V
NG Replace body ECU (See page IN±35).
OK
Replace suspension control ECU
(See page IN±35).

F19448
H12
Height Control SwitchSuspension Control
ECU
IMS25 313
S25 HI
LOHSW
LW S
DNSW 32
4 2 W±BUPSW
W L±B
E DI±774
± DIAGNOSTICSAIR SUSPENSION SYSTEM
968 Author: Date:
2005 SEQUOIA (RM1146U)
DTC C1786/86 Height Control Switch Circuit
(Test Diagnosis)
CIRCUIT DESCRIPTION
Vehicle height can be chosen by pressing the height control switch.
By pressing the ºUPº side, vehicle height goes up.
By pressing the ºDOWNº side, vehicle height goes down.
HINT:
This DTC is output only when the sensor signal check is done.
DTC No.DTC Detecting ConditionTrouble Area
C1786/86Height control switch signal does not change.

Height control switch

Height control switch circuit

Suspension control ECU
WIRING DIAGRAM
DIDED±01

± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±775
969 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
HINT:
Start the inspection from step 1 when using the hand±held tester and start from step 2 when not using the
hand±held tester.
1 Read value of the hand±held tester.
PREPARATION:
(a) Connect the hand±held tester to the DLC3.
(b) Turn the ignition switch ON, and turn the hand±held tester main switch ON.
(c) Select the item ºHEIGHT SW DOWNº or ºHEIGHT SW UPº in the DATA LIST, and read its value dis-
played on the hand±held tester.
AIR SUSPENSION:
ItemMeasurement Item / Range (Dis-
play)Normal ConditionDiagnostic Note
HEIGHT SW DOWNHeight control switch (DOWN) /
ON or OFFON: Height control switch
ºDOWNº button is pressed
OFF: ±
±
HEIGHT SW UPHeight control switch (UP) / ON or
OFFON: Height control switch ºUPº
button is pressed
OFF: ±
±
CHECK:
Check that the value displayed on the hand±held tester changes by pressing the height control switch ºUPº
or ºDOWNº.
OK:
Height control switch value changes.
RESULT:
NGA
OK (When troubleshooting according to the PROBLEM SYMPTOMS TABLE)B
OK (When troubleshooting according to the DTC chart)C
B Proceed to next circuit inspection shown in
problem symptoms table (See page DI±716).
C Replace suspension control ECU
(See page IN±35).
A

F19433
3
UP Button
DOWN Button
Height Control
Switch
12 45
DI±776
± DIAGNOSTICSAIR SUSPENSION SYSTEM
970 Author: Date:
2005 SEQUOIA (RM1146U)
2 Inspect height control switch.
PREPARATION:
Remove the height control switch connector.
CHECK:
Check continuity between each terminal of the height control
switch when the height control switch ºUPº or ºDOWNº button
is pressed.
OK:
Tester connectionSwitch conditionSpecification
ºUPº button2 ± 3Continuity
ºDOWNº button2 ± 3No continuity
ºUPº button2 ± 4No continuity
ºDOWNº button2 ± 4Continuity
NG Replace height control switch.
OK

F16805
Suspension Control ECU
Wire Harness View:
S25
UPSW
DNSW
F19462
Height Control Switch Wire Harness
Side Connector Front View:
H12
ELW S
HSW
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±777
971 Author: Date:
2005 SEQUOIA (RM1146U)
3 Check harness and connector (Height control switch ± Suspension control ECU,
Body ground).
PREPARATION:
Disconnect the ECU connector.
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
Tester connection
(Symbol)ConditionSpecified condition
S25±13 (UPSW) ±
H12±3 (HSW)AlwaysBelow 1 W
S25±32 (DNSW) ±
H12±4 (LWS)AlwaysBelow 1 W
H12±2 (E) ± Body groundAlwaysBelow 1 W
S25±13 (UPSW) ±
Body groundAlways10 kW or higher
S25±32 (DNSW) ±
Body groundAlways10 kW or higher
NG Repair or replace harness or connector.
OK
Replace suspension control ECU
(See page IN±35).

F19449
H17
Height Control Mode
Select SwitchSuspension Control
ECU
W±B
IM4BR±B
312
S25
TD DI±778
± DIAGNOSTICSAIR SUSPENSION SYSTEM
972 Author: Date:
2005 SEQUOIA (RM1146U)
DTC C1788/88 Height Control Mode Select Switch Circuit
(Test Diagnosis)
CIRCUIT DESCRIPTION
Height control can be operated or suspended by pressing the height control mode select switch.
By pressing the switch once, height control can be suspended.
By pressing the switch one more time, height control can be operated.
HINT:
The DTC is output only when the sensor signal check is done.
DTC No.DTC Detecting ConditionTrouble Area
C1788/88Height control mode select switch signal does not change.

Height control mode select switch

Height control mode select switch circuit

Suspension control ECU
WIRING DIAGRAM
DIDEF±01