2001 TOYOTA SEQUOIA height

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

± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±779
973 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 HOLDº in the DATA LIST, and read its value displayed on the hand±held
tester.
AIR SUSPENSION:
ItemMeasurement Item / Range (Dis-
play)Normal ConditionDiagnostic Note
HEIGHT SW HOLDHeight control mode select switch
/ ON or OFFON: Height control mode select
switch is pressed
OFF: ±
±
CHECK:
Check that the value displayed on the hand±held tester changes by pressing the height control mode select
switch.
OK:
Height control mode select 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

F19434
43
Height Control Mode Select Switch
Pushed In
Free
DI±780
± DIAGNOSTICSAIR SUSPENSION SYSTEM
974 Author: Date:
2005 SEQUOIA (RM1146U)
2 Inspect height control mode select switch.
PREPARATION:
Disconnect the height control mode select switch connector.
CHECK:
Check continuity between terminals 3 and 4 of the height con-
trol mode select switch when the height control mode select
switch is pushed in and free.
OK:
Switch conditionSpecification
Pushed inContinuity
FreeNo continuity
NG Replace height control mode select switch.
OK

F16805
Suspension Control ECU
Wire Harness View:
S25
TD
F19463
Height Control Mode Select Switch
Wire Harness Connector Front View:
H17
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±781
975 Author: Date:
2005 SEQUOIA (RM1146U)
3 Check harness and connector (Height control mode select switch ± Suspension
control ECU).
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±12 (TD) ± H17±3AlwaysBelow 1 W
H17±4 ± Body groundAlwaysBelow 1 W
S25±12 (TD) ±
Body groundAlways10 kW or higher
NG Repair or replace harness or connector.
OK
Replace suspension control ECU
(See page IN±35).

F19450
C6
Combination
MeterSuspension Control
ECU
I18
Ignition SW Instrument Panel J/B
Engine Room J/B24
14
15
16 LO
N
HIP
B±L
GR±R26
S25
9
S25
8
S25LO
NR
HI
6
IG2 AM25
W±R B±R IGN1 11
7 1H
1J1C
1C32
W±R
AM2
1
2C
2D1
B
Battery B±O
B 5 4F10
FL Block
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±785
979 Author: Date:
2005 SEQUOIA (RM1146U)
Height Control Indicator Lamp Circuit
CIRCUIT DESCRIPTION
The height control indicator lamp indicates the target height, not the actual height.
It blinks when the height control is operated by pressing the height control switch and stays on when the
operation is completed.
WIRING DIAGRAM
DIDEL±01

DI±786
± DIAGNOSTICSAIR SUSPENSION SYSTEM
980 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Inspect height control indicator lamp.
PREPARATION:
Turn the ignition switch to the ON position.
CHECK:
Check that the height control indicator lamp comes on.
OK:
Height control indicator lamp comes on, and then goes off after 2 seconds.
NG Go to combination meter system
(See page DI±1610).
OK

F19451
C6
Combination
MeterSuspension Control
ECU
I18
Ignition SW
Engine Room J/B Instrument Panel J/B B±O
W±R11
7 1H
1JIGN1
1C
1C32
B±RMAN. 24
13 LG11
S25 VN
5
IG2 AM2 6
W±R
B
Battery 1
2D AM2
2C1
B5 4F10
FL Block
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±789
983 Author: Date:
2005 SEQUOIA (RM1146U)
Height Control Manual Indicator Lamp Circuit
CIRCUIT DESCRIPTION
When manual mode is selected by pressing the height control mode select switch, the manual indicator lamp
comes on. (For the wiring diagram of the height control mode select switch circuit, see page DI±778.) If the
suspension control ECU detects a problem, the height control manual indicator lamp blinks while suspend-
ing the height control function. At the same time, the suspension control ECU records a DTC in the memory.
Connect terminals TC and CG of the DLC3 to make the height control manual indicator lamp blink and output
DTCs.
WIRING DIAGRAM
DIDEN±01