2001 TOYOTA SEQUOIA 4WD

± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±701
895 Author: Date:
2005 SEQUOIA (RM1146U)
2. REAR AIR SUSPENSION SYSTEM DESCRIPTION
(a) Auto leveling function
The function to keep the rear vehicle height fixed regardless of the change in the number of the occupants
or the load.
(b) Vehicle height control function
(1) Mode change:
The mode can be changed between the auto mode and the manual mode by operating the
height control mode select switch.
Vehicle height control can be canceled by changing the height control mode select switch
to manual mode.
(2) Auto mode:
Vehicle height can be set to NORMAL, HIGH (+40 mm (1.57 in.)) or LOW (4WD: ±30 mm
(±1.18 in.), 2WD: ±15 mm (±0.59 in.)) by operating the height control switch.
When vehicle speed is 12 km/h (7.46 mph) or less, vehicle height is LOW.
When vehicle speed is 30 km/h (18.64 mph) or less, vehicle height is HIGH.
(3) Manual mode:
Vehicle height can be set in any level within the vehicle height adjustable range by operat-
ing the height control switch.
Vehicle speed is 30 km/h (18.64 mph) or less.
(4) Adjusting time:
Approximately 20 seconds is needed to adjust vehicle height to UP (+40 mm (1.57 in.)).
Approximately 30 seconds is needed to adjust vehicle height to DOWN (±40 mm (±1.18
in.)).
(c) Vehicle speed detection function
When any of the following conditions are met with the vehicle height set to any position other than
NORMAL, vehicle height is automatically adjusted to NORMAL.
AUTO MODE: When vehicle speed is 12 km/h (7.46 mph) or less, vehicle height is LOW.
AUTO MODE: When vehicle speed is 30 km/h (18.64 mph) or less, vehicle height is HIGH.
MANUAL MODE: Vehicle speed is 30 km/h (18.64 mph) or less.
(d) Vehicle height adjustment control after turning the ignition switch off
If the rear vehicle height is raised after the ignition switch is turned off, such as when the occupant gets out
of the vehicle, vehicle height is lowered to the correct position for several seconds even after the ignition
switch is turned off.
(e) Fail±safe
If the vehicle control switch is operated frequently to change vehicle height, vehicle height control is sus-
pended for a while to prevent the compressor from becoming overheated.

DI±728
± DIAGNOSTICSAIR SUSPENSION SYSTEM
922 Author: Date:
2005 SEQUOIA (RM1146U) MAIN RELAY
MAIN relay / ON or OFFON: MAIN relay operated
OFF: MAIN relay not operated±
MOTOR RELAYAIR SUS relay / ON or OFFON: Compressor operated
OFF: Compressor not operated±
RR HEIGHT
Right rear height control sensor
reading / min.: ±3276.7 mm
(±129.004 in.), max.: 3276.8 mm
(129.008 in.)
Always: 0 mm (0 in.)±
RL HEIGHT
Left rear height control sensor
reading / min.: ±3276.7 mm
(±129.004 in.), max.: 3276.8 mm
(129.008 in.)
2WD:
Min.: ±15 mm (±0.59 in.)
Max.: 40 mm (1.57 in.)
4WD:
Min.: ±30 mm (±1.18 in.)
Max.: 40 mm (1.57 in.)
±
#CODESNumber of DTC recorded / min.: 0,
max.: 255Min.: 0, Max.: XX±
2. ACTIVE TEST LIST
HINT:
Perform the ACTIVE TEST using the hand±held tester to operate the sensors, relays and solenoids without
removing any parts. Performing the ACTIVE TEST is the first step of troubleshooting and is one of the meth-
ods to shorten labor time. It is possible to display the DATA LIST during the ACTIVE TEST.
(a) Connect the hand±held tester to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Following the display on the tester, perform the ACTIVE TEST.
AIR SUSPENSION:
ItemVehicle Condition / Test DetailsDiagnostic Note
RR HEIGHTTurn height control switch / UP or DOWN±
LEVEL SOL REARTurn leveling solenoid valve / ON or OFFOperation sound of solenoid (clicking sound) can
be heard
GATE SOL REARTurn gate solenoid valve / ON or OFFOperation sound of solenoid (clicking sound) can
be heard
MOTOR RELAYTurn AIR SUS relay / ON or OFFOperation sound of motor can be heard

DI±732
± DIAGNOSTICSAIR SUSPENSION SYSTEM
926 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
HINT:

Proceed to troubleshooting following the flow chart, regardless of whether or not DTC C1714/14 is dis-
played.

If DTC C1761/61 (ECU malfunction) and/or C1774/74 (power source circuit) is displayed, perform the
inspection necessary for DTC C1761/61 (See page DI±761) and/or C1774/74 (See page DI±763)
first.
(If DTC C1761/61 and C1774/74 are output at the same time, perform the inspection necessary for
DTC C1774/74 first.)

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 to the ON position, and push the hand±held tester main switch ON.
(c) Select the item ºRL HEIGHTº in the DATA LIST, and read its value displayed on the hand±held tester.
AIR SUSPENSION:
ItemMeasurement Item / Range (Dis-
play)Normal ConditionDiagnostic Note
RL HEIGHT
Left rear height control sensor
reading / min.: ±3276.7 mm
(±129.004 in.), max.: 3276.8 mm
(129.008 in.)
2WD:
Min.: ±15 mm (±0.59 in.)
Max.: 40 mm (1.57 in.)
4WD:
Min.: ±30 mm (±1.18 in.)
Max.: 40 mm (1.57 in.)
±
CHECK:
Check the vehicle height value of the height control sensor sub±assy with the hand±held tester while press-
ing the height control switch ºUPº or ºDOWNº.
OK:
Vehicle height 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

DIDLV±01
F17996
Front Speed SensorABS & VSC Actuator
(w/ Skid Control ECU)Level Warning Switch
Rear Speed Sensor Rear Speed Sensor Rotor
Front Speed
Sensor Rotor
Parking Brake SwitchStop Light Switch
Center Diff. Lock Switch *1
TRAC OFF Switch *2
Steering Angle Sensor
DLC3Brake Inhibit RelayTranslate ECU
VSC BuzzerBrake Booster
(Including Active Brake Booster
Solenoid, Delta S Sensor and Boost-
er Pedal Switch)
Master Cylinder
Pressure Sensor
Front Speed Sensor Rotor
Front Speed Sensor
Yaw Rate Sensor
(Including Deceleration Sensor)
ABS Warning Light
VSC TRAC Warning light
VSC OFF Indicator Light *
1
TRAC OFF Indicator Light *2
BRAKE Warning Light
SLIP Indicator Light
*1: Only for 4WD
*2: Only for 2WDCenter Diff. Lock
Position Switch
DI±892
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
1086 Author: Date:
2005 SEQUOIA (RM1146U)
LOCATION

DIDLW±01
F19153
Speed Sensor
(Each Wheel)
Stop Lamp Switch
Parking Brake Switch
Delta S Sensor
Yaw Rate
(Deceleration) SensorABS & VSC Actuator
Skid Control
ECUCombination
Meter
Translate
ECUSteering Angle
Sensor
4WD ECU
ECM
CAN Communication SystemAir Suspension ECU (*1): CAN1 Circuit
(*2): CAN2 Circuit
(*3): Vehicle CAN Circuit(*2)
(*3) (*1)
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
DI±893
1087 Author: Date:
2005 SEQUOIA (RM1146U)
SYSTEM DIAGRAM

DI93A±03
Inspector 's
Name:
Customer 's Name
Date Vehicle
Brought InRegistration DateRegistration No.
Frame No.
Odometer Reading/ /
/ /
Date Problem First Occurred
Frequency Problem Occurs/ /
ContinuousIntermittent ( times a day)
Remains ONDoes not Light Up
DTC Check1st Time
2nd TimeNormal System Code
Trouble Code (Code )
Symptomskm
miles
Check ItemNormal
ABS does not operate.
ABS does not operate efficiently.
Does not Light Up
ABS & BA & TRAC & VSC Check Sheet
VSC does not operate. (Wheels sideslip when turning sharply.)
ABS Warning Light
Abnormal
Remains ON
Does not Light Up
Remains ONDoes not Light Up
Remains ONDoes not Light Up
Remains ONDoes not Light Up
TRAC OFF Indicator
Light Abnormal*1
SLIP Indicator
Light Abnormal VSC TRAC Warning
Light Abnormal
BRAKE Warning
Light Abnormal
Malfunction
Indicator Light
TRAC does not operate. (Wheels spin when starting off rapidly.)
Remains ON
Does not Light UpVSC OFF Indicator
Light Abnormal*2
BA does not operate
Normal System Code
Trouble Code (Code )
DI±896
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
1090 Author: Date:
2005 SEQUOIA (RM1146U)
CUSTOMER PROBLEM ANALYSIS CHECK
*1: Only for 2WD
*2: Only for 4WD

DIDLY±01
F09750
DLC3
Ts
Tc
CG
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
DI±897
1091 Author: Date:
2005 SEQUOIA (RM1146U)
CALIBRATION
1. ZERO POINT CALIBRATION OF MASTER CYLINDER
PRESSURE, YAW RATE AND DECELERATION SEN-
SORS
HINT:
When having replaced the master cylinder pressure, yaw rate
and deceleration sensors and/or the ECU, make sure to per-
form master cylinder pressure, yaw rate and deceleration sen-
sors' zero point calibration.
NOTICE:

While obtaining the zero point, do not vibrate the ve-
hicle by tilting, moving or shaking it and keep it in a
stationary condition. (Do not start the engine.)

Be sure to do this on a level surface (within an inclina-
tion of 1 degree).
(a) Perform master cylinder pressure, yaw rate and decelera-
tion sensors zero point calibration.
(1) Using SST, connect terminals Ts and CG of the
DLC3.
SST 09843±18040
(2) Shift the shift lever to the P position.
(3) Turn the ignition switch to the ON position.
(4) Keep the vehicle in a stationary condition on a level
surface for 4 sec. or more.
(5) Keep your foot off the brake pedal.
Do not leave 4WD vehicles in the L4 position.
(6) Press the center diff. lock (TRAC OFF) switch 3
times within 3 seconds.
(7) Check that the VSC buzzer sounds for 3 seconds.
HINT:

If the VSC buzzer does not sound, do the zero point cal-
ibration again and/or check the VSC buzzer circuit (See
page DI±1052).

If the VSC buzzer does not sound, check for yaw rate and
deceleration sensor failure (See page DI±911).
(8) Turn the ignition switch OFF.
(9) Disconnect terminals Ts and CG of the DLC3.
(b) Perform steering angle sensor zero point calibration.
This calibration is carried out automatically by following
procedures below:
(1) Make sure the system is not in sensor check mode.
(2) Calibrate the steering angle sensor by driving the
vehicle in a straight line at more than 7 MPH (12
km/h) for 5 seconds.

F16975
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
DI±909
1103 Author: Date:
2005 SEQUOIA (RM1146U)
Translate ECU:
Symbols (Terminal No.)Wiring ColorTerminal DescriptionConditionSpecified Condition
IG1 (1) ± GND (40)B±R ± OTranslate ECU power
supplyIG SW ON10 to 14 V
PKB2 (4) ± GND (40)LG±R ± OPKB signal lineIG SW ON, PKB SW ONBelow 2.0 V
PKB2 (4) ± GND (40)LG±R ± OPKB signal lineIG SW ON, PKB SW OFF10 to 14 V
VSC+ (7) ± VSC± (11)L ± WCAN communication lineIG switch ONPulse generation
ENG+ (14) ± ENG± (16)R ± WECM communicationIG SW ONPulse generation
SS1+ (18) ± SS1± (19)O ± YSteering angle sensor lineIG SW ONPulse generation
TRIG (20) ± GND (40)W±L ± OSteering angle sensor sig-
nalIG SW ON4.5 to 5.5 V
LVL2 (24) ± GND (40)Y±L ± OBrake fluid level signalBrake fluid level SW ONBelow 1.5 V
CSW (26)* ± GND (40)L±W ± OCenter diff. lock SW sig-
nalIG SW ON, VSC OFF SW ONBelow 1.5 V
CSW (26)* ± GND (40)L±W ± OCenter diff. lock SW sig-
nalIG SW ON, VSC OFF SW OFF8 to 14 V
TS (27) ± GND (40)R±L ± OSensor check inputIG switch ON10 to 14 V
TC (28) ± GND (40)P±B ± ODiagnosis tester commu-
nication lineIG switch ON10 to 14 V
CD (29)* ± GND (40)BR±Y ± OCenter diff. lock lamp sig-
nalIG SW ON, center diff. lock indica-
tor ONBelow 1.5 V
CD (29)* ± GND (40)BR±Y ± OCenter diff. lock lamp sig-
nalIG SW ON, center diff. lock indica-
tor OFF8 to 14 V
EXI2 (31)* ± GND (40)Y±G ± OCenter diff. lock signalIG SW ON, center diff. lock SW ONBelow 1.5 V
EXI2 (31)* ± GND (40)Y±G ± OCenter diff. lock signalIG SW ON, center diff. lock SW
OFF8 to 14 V
IND (37) ± GND (40)W±R ± OSLIP indicator signalIG SW ON, SLIP indicator ONBelow 2.0 V
IND (37) ± GND (40)W±R ± OSLIP indicator signalIG SW ON, SLIP indicator OFF10 to 14 V
WT (38) ± GND (40)R±G ± OVSC OFF or TRAC OFF
warning light circuitIG SW ON, VSC OFF or TRAC
OFF warning light ONBelow 2.0 V
WT (38) ± GND (40)R±G ± OVSC OFF or TRAC OFF
warning light circuitIG SW ON, VSC OFF or TRAC
OFF warning light OFF10 to 14 V
BRL (39) ± GND (40)R±B ± OBRAKE warning light cir-
cuitIG SW ON, BRAKE warning light
ONBelow 2.0 V
BRL (39) ± GND (40)R±B ± OBRAKE warning light cir-
cuitIG SW ON, BRAKE warning light
OFF10 to 14 V
*: Only for 4WD