2001 TOYOTA SEQUOIA engine

G23400G23400D14177
Accelerator Pedal
Opening Angle
Lock±up OFF
Lock±up ON
"time Engine Speed
Accelerator Pedal
Fully Released DI±676
± DIAGNOSTICSAUTOMATIC TRANSMISSION
870 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
HINT:
Performing the ACTIVE TEST using the hand±held tester allows the relay, VSV, actuator and so on to oper-
ate without parts removal. Performing the ACTIVE TEST as the first step of troubleshooting is one method
to shorten labor time.
It is possible to display the DATA LIST during the ACTIVE TEST.
(a) Warm up the engine.
(b) Turn the ignition switch off.
(c) Connect the hand±held tester to the DLC3.
(d) Turn the ignition switch to the ON position.
(e) Turn on the tester.
(f) Select the item ºDIAGNOSIS / ENHANCED OBD II / ACTIVE TESTº.
(g) According to the display on the tester, perform the ºACTIVE TESTº.
ItemTest DetailsDiagnostic Note
LOCK UP
[Test Details]
Control the shift solenoid SLU to set the automatic transmission to the
lock±up condition.
[Vehicle Condition]

Throttle valve opening angle: Less than 35 %

Vehicle Speed: 60 km/h (37 mph) or more
Possible to check the SLU opera-
tion.
HINT:

This test can be conducted when the vehicle speed is 60 km/h (37 mph) or more.

This test can be conducted in the 5th gear.

Lightly depress the accelerator pedal and check that the engine speed does not change abruptly.
HINT:

When changing the accelerator pedal opening angle while driving, if the engine speed does not
change, lock±up is on.

Slowly release, but not fully, the accelerator pedal in order to decelerate. (Fully releasing the pedal will
close the throttle valve and lock±up may be turned off automatically.)

DIDCF±01
F19439
Crankshaft
Position SensorEngine Room R/B No. 3
Engine Room J/B
Instrument
Panel J/B

STOP Fuse

IGN1 Fuse

ECU±IG Fuse
Stop Light
Switch
Combination Meter
Height Control Switch Body ECU
ECM Engine Room R/B No. 2
Suspension Control ECU
Translate ECU
4LO Switch
2WD/4HI Switch
Height Control Mode Select SwitchIgnition Switch
Height Control Indicator
Fusible Link Block

AIR SUS Fuse

AM2 Fuse

Height Control Manual IndicatorCenter Diff. Lock Switch
DLC3
Vehicle Speed Sensor
Vehicle Speed Sensor

AIR SUS Relay

AIR SUS No. 2 Fuse DI±696
± DIAGNOSTICSAIR SUSPENSION SYSTEM
890 Author: Date:
2005 SEQUOIA (RM1146U)
LOCATION

± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±699
893 Author: Date:
2005 SEQUOIA (RM1146U)
Input and output signals of each ECU.
Transmitting ECUReceiving ECUSignalCommunication method
ECM

Translate ECU

Suspension control
ECU

Engine speed signal

Transmission signal

Shift position signal

L4 switch signal

TC signal
CAN
Translate ECUSuspension control
ECU
Vehicle wheel speed signal

TS signalCAN
Suspension control ECUTranslate ECUAir suspension setting signalCAN

DIDCN±01
F19465
: CAN
Compressor Assy
Combination Meter
Suspension
Control
ECU Exhaust Solenoid
Valve
Gate Solenoid Valve
Leveling Solenoid ValveAIR SUS Relay
Height Control Cylinder
(Pneumatic Cylinder)
Height Control Sensor
Sub±assy : ECU Output Signal
: ECU Input Signal
: Air Flow Path
Dryer
Height Control Cylinder
(Pneumatic Cylinder)
Speed Sensors

Engine Speed

L4 Switch

Shift Position
Information

Transmission
Model Informa-
tion

Height Control Mode Select
Switch

Height Control Switch

Courtesy Light Switches

Stop Light SwitchHI
N
LO
MAN. DI±700
± DIAGNOSTICSAIR SUSPENSION SYSTEM
894 Author: Date:
2005 SEQUOIA (RM1146U)
SYSTEM DESCRIPTION
1. GENERAL
This system uses pneumatic cylinders instead of the coil springs that are used in a conventional rear
suspension. The suspension control ECU analyzes the information based on the switches, sensors,
and input signals, operates the compressor assy, and uses the solenoid valves to control the vehicle
height.
The suspension control ECU detects, via the height control sensor, the changes in the rear vehicle
height that results from the number of occupants or the amount of the load. Then, the suspension con-
trol ECU controls the height control solenoid valves and the compressor assy in order to automatically
adjust the rear vehicle height to a constant (normal) vehicle height.
Furthermore, three vehicle heights can be selected by operating the height control switch: HI, NOR-
MAL, and LO. The HI vehicle height ensures the vehicle's drive±through performance on rough roads.
The LO vehicle height facilitates the entry and exit of the occupants and the loading and unloading
of cargo. The NORMAL vehicle height helps realize excellent controllability and riding comfort during
normal driving.

DI±702
± DIAGNOSTICSAIR SUSPENSION SYSTEM
896 Author: Date:
2005 SEQUOIA (RM1146U)
3. FUNCTION OF MAIN COMPONENTS
ComponentOutline
Height Control Mode Select SwitchUsed to select vehicle height control mode (Auto/Manual).
Used to operate or stop auto leveling control.
Height Control SwitchAuto mode: Used to select vehicle height (HIGH, NORMAL, LOW).
Manual mode: Used to select vehicle height optionally.
Height Control SensorConverts the vertical change of the rear axle, in proportion to the standard, to sig-
nals and detects vehicle height.
Height Control Indicator Lamp (Combination Meter)Auto mode: Target vehicle height is displayed (HIGH, NORMAL, LOW).
Manual mode: Current vehicle height is displayed (HIGH, NORMAL, LOW).
Height Control Manual Indicator Lamp (Combination Meter)
Comes on during manual mode.
Blinks when the suspension control ECU detects a system malfunction.
Blinks during test mode.
Displays output DTC.
Stop light SwitchDetects braking condition.
Used to clear DTCs.
Pneumatic Cylinder (Height Control Cylinder Assy)Supports the vehicle body and adjusts the vehicle height.
Height Control Compressor Assy (Compressor/Height Con-
trol Dryer)The compressor generates compressed air that is necessary to raise vehicle
height and supplies it to the height control cylinder assy.
The dryer removes moisture from the compressed air.
Exhaust Solenoid ValveDrains the air in the height control cylinder assy when vehicle height is lowered.
(Built into the height control compressor assy)
Leveling Solenoid ValveOpens or closes the passage between the height cylinder assy and height control
compressor assy.
Gate Solenoid ValveOpens or closes the passage between the right and left height control cylinder assy
(Built into the leveling solenoid valve).
Suspension Control ECU
Estimates vehicle condition based on the signals from sensors and switches, and
outputs the control signals to the compressor and valves.
Blinks the height control manual indicator light when a system malfunction is de-
tected.
Air Suspension RelaySupplies power to the height control compressor assy.
Door Courtesy Switch (Body ECU)Detects whether the 5 doors, including the back door, are opened or closed, and
sends the signals to the suspension control ECU.
ECMSends the engine speed signal, etc. to the suspension control ECU through CAN
communication.
Speed Sensor (Skid Control ECU)Sends the vehicle wheel speed signal, etc. to the suspension control ECU through
CAN communication via the translate ECU.

F19466
Compressor Motor Exhaust Solenoid
ValveDryer
Compressor Portion
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±703
897 Author: Date:
2005 SEQUOIA (RM1146U)
4. CONSTRUCTION AND OPERATION OF MAIN COMPONENTS
Compressor Assy
The compressor and motor are used to make the compressed air necessary for raising the vehicle
height.
The exhaust solenoid valve is provided on the compressor assy. The exhaust solenoid valve dis-
charges compressed air from the pneumatic cylinders to the atmosphere in order to lower the vehicle.
The dryer is used to eliminate the moisture in the compressed air made by the compressor and motor.
To protect the battery, this compressor assy operates only when the engine is running.
Specification
MotorTypeDC
MotorRated Voltage12 V
Exhaust Solenoid ValveRated Voltage12 V
Exhaust Solenoid ValveOperating Voltage Range10 to 15 V
Exhaust Solenoid ValveResistance10 to 14 W

DIDD3±01
F16803
S25
DI±718
± DIAGNOSTICSAIR SUSPENSION SYSTEM
912 Author: Date:
2005 SEQUOIA (RM1146U)
TERMINALS OF ECU
Symbols (Terminal No.)Wiring ColorTerminal
DescriptionConditionSpecified Condition
SLEX (S25±1) ± LR WB
Exhaust Sole-
id V l Si
IG switch ON "
E i idli b tt f h i ht t l it h i h dBelow 1.0 V "SLEX (S25 1)
GND (S25±22)L±R ± W±Bnoid Valve Sig-
nalEngine idling, button of height control switch is pushed
from ºUPº to ºDOWNºBelow 1.0 V "
9 V or more
SLRR (S25±3) ± LG R W B
Leveling Sole-
id V l Si
IG switch ON "
E i idli b tt f h i ht t l it h i h dBelow 1.0 V "SLRR (S25 3)
GND (S25±22)LG±R ± W±Bnoid Valve Sig-
nalEngine idling, button of height control switch is pushed
from ºDOWNº to ºUPºBelow 1.0 V "
9 V or more
SLRL (S25±4) ± WL WBGate SolenoidIG switch ON "
E i idli b tt f h i ht t l it h i h dBelow 1.0 V "SLRL (S25 4)
GND (S25±22)W±L ± W±BGate Solenoid
Valve SignalEngine idling, button of height control switch is pushed
from ºDOWNº to ºUPºBelow 1.0 V "
9 V or more
RC (S25±5) ± GY WBAIR SUS RelayIG switch ON "
E i idli b tt f h i ht t l it h i h dBelow 1.0 V "RC (S25 5)
GND (S25±22)G±Y ± W±BAIR SUS Relay
SignalEngine idling, button of height control switch is pushed
from ºNº to ºUPºBelow 1.0 V "
9 V or more
HI (S25±8) ± GR R W B
Height Control
I di t ºHIº
Engine idling, vehicle height is ºNORMALº "
P i th ºUPº b tt f th t l it h t10 V or more "HI (S25 8)
GND (S25±22)GR±R ± W±BIndicator ºHIº
SignalPressing the ºUPº button of the control switch turns on
the ºHIº indicator lamp (*1)10 V or more "
Below 5 V
NR (S25±9) ± BL WB
Height Control
I di t ºNº
Engine idling, vehicle height is ºNORMALº "
P i th ºUPº b tt f th t l it h tBelow 5 V "NR (S25 9)
GND (S25±22)B±L ± W±BIndicator ºNº
SignalPressing the ºUPº button of the control switch turns on
the ºHIº indicator lamp (*1)Below 5 V "
10 V or more
IG (S25±10) ±
GND (S25±22)B±R ± W±BIgnition SwitchIG switch ON10 to 14 V
VN (S25±11) ± LG W B
Height Control
MlIdi
IG switch ON, height control manual indicator lamp ON
" Pressin
g and releasing the height control mode selectBelow 5 V "VN (S25 11)
GND (S25±22)LG ± W±BManual Indica-
tor Lamp Signal" Pressing and releasing the height control mode select
switch turns off the height control manual indicator lamp
(*1)
Below 5 V "
10 V or more
TD (S25±12) ± BR B W B
Height Control
Md Sl t
IG switch ON, height control mode select switch pushed
iBelow 1.5 V "TD (S25 12)
GND (S25±22)BR±B ± W±BMode Select
Switchin
" Height control select switch releasedBelow 1.5 V "
10 to 14 V
UPSW (S25±13) ± LB WB
Height Control
S it h ºUPº
IG switch ON, ºUPº button of height control switch
hdiBelow 1.5 V "UPSW (S25 13)
GND (S25±22)L±B ± W±BSwitch ºUPº
Signalpushed in "
ºUPº button of height control switch releasedBelow 1.5 V "
10 to 14 V
SBL (S25±15) ±
SGL (S25±19)G±O ± L±R
Height Control
Sensor Power
Source
IG switch ON4.5 to 5.5 V
SHRL (S25±17) ± GR L L R
Height Control
SIt
IG switch ON "
E i idli hi l h i ht i h d f ºHIGHº t0.5 to 4.5 V "SHRL (S25 17)
SGL (S25±19)GR±L ± L±RSensor Input
SignalEngine idling, vehicle height is changed from ºHIGHº to
ºNORMALº by pressing the height control switch0.5 to 4.5 V "
Approx. 2.5 V
SGL (S25±19) ±
GND (S25±22)L±R ± W±BHeight Control
Sensor GroundAlwaysBelow 1.0 V

F16807
GND
F19430
GND
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±719
913 Author: Date:
2005 SEQUOIA (RM1146U) RM+ (S25±20) ±
GND (S25±22)
R±L ± W±B
Height Control
Compressor
Motor Lock (+)Engine idling, vehicle height changes from ºNORMALº to
ºHIGHº by pressing the height control switch (While
height control compressor assy is working).
Below 1.0 V
RM± (S25±21) ±
Body groundBR±Y ± W±B
Height Control
Compressor
Motor Lock (±)
AlwaysBelow 1.0 V
GND (S25±22) ±
Body groundW±B ±
Body groundGroundAlwaysBelow 1.0 V
B (S25±24) ±
GND (S25±22)V ± W±BBatteryIG switch ON10 to 14 V
LO (S25±26) ± PWB
Height Control
I di t ºLOº
Engine idling, vehicle height is ºNORMALº "
P i th ºDOWNº b tt f th h i ht t l it h10 V or more "LO (S25 26)
GND (S25±22)P ± W±BIndicator ºLOº
SignalPressing the ºDOWNº button of the height control switch
turns on the ºLOº indicator lamp (*1)10 V or more "
Below 5 V
STP (S25±27) ± GY WBStop LightBk dld dRl d10 to 14 V "STP (S25 27)
GND (S25±22)G±Y ± W±BSto Light
SwitchBrake pedal depressed " Released10 to 14 V "
Below 1.5 V
SIL (S25±30) ±
GND (S25±22)G±R ± W±BDiagnosis Sig-
nalHand±held tester is connected to DLC3Pulse generation
(See waveform 3)
DOOR (S25±31) ± RWBDSilIG switch ON, each door opened "Below 1.5 VDOOR (S25 31)
GND (S25±22)R ± W±BDoor SignalIG switch ON, each door o ened "
All door closed
Below 1.5 V
10 to 14 V
DNSW (S25±32) ±
GND (S25±22)W ± W±B
Height Control
Switch
ºDOWNº SignalIG switch ON, ºDOWNº button of height control switch
pushed in "
ºDOWNº button of height control switch releasedBelow 1.5 V "
10 to 14 V
BAT (S25±25) ±
GND (S25±22)V ± W±BBatteryAlways10 to 14 V
CANL (S25±28) ±
GND (S25±22)W ± W±BCAN Commu-
nication SignalIG switch ONPulse generation
(See waveform 1)
CANH (S25±29) ±
GND (S25±22)G ± W±BCAN Commu-
nication SignalIG switch ONPulse generation
(See waveform 2)
*1: Perform inspection after checking that the height control indicator lamp switches are illuminated when
the height control switch button is pressed.
Waveform 1 (Reference):
ItemContents
TerminalCANL ± GND
Tool setting1V/DIV, 10ms/DIV
Vehicle conditionIgnition SW ON, Engine stopped
Waveform 2 (Reference):
ItemContents
TerminalCANH ± GND
Tool setting1V/DIV, 10ms/DIV
Vehicle conditionIgnition SW ON, Engine stopped