height TOYOTA SEQUOIA 2001 Service User Guide

DIDIP±01
12345678
9 10111213141516
D13649
DLC3:
CG
TC
D13654
DI±524
± DIAGNOSTICSAUTOMATIC TRANSMISSION
718 Author: Date:
2005 SEQUOIA (RM1146U)
BASIC INSPECTION
1. CHECK FLUID LEVEL
(a) Using SST, create a short±circuit between terminals TC
and CG of the DLC3.
SST 09843±18040
(b) Start the engine and run at idle.

The A/C switch must be turned off.

On models with active height control suspension &
adaptive variable suspension, turn the height con-
trol switch off.
(c) Slowly move the shift lever through all positions from P to
L, and move it back to the P position.
(d) Switch to the fluid temperature detection mode.
Move the shift lever from the N to the D position, or from
D to N, within 1.5 seconds. (Repeat this operation for 6 se-
conds or more.)
OK: The A/T OIL TEMP warning light comes on for 2
seconds and then goes off.
(e) Return the shift lever to the P position and disconnect ter-
minals TC and CG.
(f) Idle the engine to raise oil temperature.
(g) Lift up the vehicle immediately after the meter indicator
light (ATF temperature warning light) comes on.

The A/T OIL TEMP warning light indicates the ATF
temperature according to the following table.
ATF Temp.Less than optimized
temperatureOptimized temperatureMore than optimized
temperature
A/T OIL TEMP warning lightOFFONBlinking

D14139Overflow Plug
D14140
Refill Plug
12345678
9 10111213141516
D13649
DLC3:
CG
TC
± DIAGNOSTICSAUTOMATIC TRANSMISSION
DI±529
723 Author: Date:
2005 SEQUOIA (RM1146U)
(4) Temporarily install the gasket and overflow plug.
Torque: 20 NVm (204 kgfVcm, 15 ftVlbf)
(5) Add the proper amount of ATF through the refill
hole.
NOTICE:
Refill amount differs depending on the related procedures
indicated below.
Related proceduresRefill amount
Removal and installation of oil pan1.7 liters (1.8 us qts, 1.5 lmp.qts)
Removal of transmission valve body
assy4.3 liters (4.5 us qts, 3.8 lmp.qts)
Removal of torque converter assy5.4 liters (5.7 us qts, 4.8 lmp.qts)
(6) Temporarily install the O±ring and refill plug.
Torque: 39 NVm (400 kgfVcm, 29 ftVlbf)
(7) Lower down the vehicle.
(8) Using SST, create a short±circuit between terminals
TC and CG of the DLC3.
SST 09843±18040
(9) Start the engine and run at idle.
NOTICE:

The A/C switch must be turned off.

On models with active height control suspension &
adaptive variable suspension, turn the height control
switch off.
(10) Slowly move the shift lever from the P to the 2±L
position.
Return the shift lever to the P position.

DIDCB±01
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±695
889 Author: Date:
2005 SEQUOIA (RM1146U)
AIR SUSPENSION SYSTEM
PRECAUTION
Be sure to switch the height control mode select switch to manual mode and cancel the auto leveling
function when:

Jacking up the vehicle.

A trailer etc. is attached to the vehicle.
NOTICE:
When disconnecting the battery terminal, initialize the following system after the terminal is recon-
nected.
System NameSee Page
Back Door Power Window Control SystemBE±77

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

F19440
Height Control
Cylinder Assy
(Pneumatic Cylinder)
Height Control Valve Height Control Cylinder Assy
(Pneumatic Cylinder)
Door Courtesy Light Switch

Leveling Solenoid Valve

Gate Solenoid ValveDoor Courtesy Light Switch

Compressor/Height Control Dryer

Exhaust Solenoid Valve

Height Control Cleaner
Height Control
Sensor Sub±assy
Compressor Assy
Back Door Courtesy
Light Switch
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±697
891 Author: Date:
2005 SEQUOIA (RM1146U)

DIDCI±01
F19438
Height Control Sensor
Sub±assy
Height Control Mode
Select Switch
Body ECU
Stop Light Switch
Front Door Courtesy
Light Switch (Driver)
Front Door Courtesy
Light Switch
(Passenger)
Rear Door Courtesy
Light Switch (LH)
Rear Door Courtesy
Light Switch (RH)
Back Door Courtesy
Light SwitchCombination Meter
Leveling Solenoid Valve
AIR SUS Relay
DLC3
ECM
Translate ECU Compressor/
Height Control Dryer
Exhaust Solenoid Valve Height Control Valve
Compressor Assy Gate Solenoid Valve IG
BBAT
SBL2
SHRL
SGL2VN
HI
NR
LO
TD
UPSW
DWSW
Door
STPSLRR
SLRL
RC
RM+
RM±
SLEX
SIL
CANH
CANL
CANSuspension
Control ECU Height Control Switch
GND From IG SwitchFrom Battery
From
Battery DI±698
± DIAGNOSTICSAIR SUSPENSION SYSTEM
892 Author: Date:
2005 SEQUOIA (RM1146U)
SYSTEM DIAGRAM

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.

± 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±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