Page 905 of 4323
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
Page 906 of 4323
F19467
Height Control Cleaner
Exhaust Chamber
OUT IN
F19468
Compressed Air DI±704
± DIAGNOSTICSAIR SUSPENSION SYSTEM
898 Author: Date:
2005 SEQUOIA (RM1146U)
Height Control Cleaner
The height control cleaner consists of a filter to remove dust and debris, and an expansion chamber
to reduce the intake sound. In consideration of dusty areas, this cleaner draws air from the inside of
the vehicle cabin.
This cleaner cannot be disassembled; therefore, it is not possible to replace only the filter element.
Height Control Cylinder Assy (Pneumatic Cylinder)
The pneumatic cylinder consists of a signal type air chamber with a large compressed air capacity in order
to realize excellent riding comfort.
Page 907 of 4323
F19469
Gate Solenoid Valve
Leveling Solenoid Valve
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±705
899 Author: Date:
2005 SEQUOIA (RM1146U)
Height Control Valve
The height control valve consists of a leveling solenoid valve, and gate solenoid valve.
Specification
Leveling Solenoid ValveRated Voltage12 V
Leveling Solenoid ValveOperating Voltage Range10 to 15 V
Leveling Solenoid ValveResistance10 to 14 W
Gate Solenoid ValveRated Voltage12 V
Gate Solenoid ValveOperating Voltage Range10 to 15 V
Gate Solenoid ValveResistance17.5 to 21.5 W
Page 908 of 4323
F19470
Low
High
Link
Arm
DI±706
± DIAGNOSTICSAIR SUSPENSION SYSTEM
900 Author: Date:
2005 SEQUOIA (RM1146U)
Height Control Sensor
The height control sensor detects the vehicle height. One sensor is located in the center of the rear
frame, which is connected to the center of the rear axle via a link, in order to detect the vehicle height.
The sensor has an arm that moves along with the change in vehicle height, and the resultant change
in voltage enables the suspension control ECU to detect the vehicle height.
A semiconductor type sensor has been adopted to make it compact and heat±resistant.
HINT:
Refer to the following factors when adjusting the link of the height control sensor:
The vehicle height changes approximately 4 mm (0.16 in.) with each turn of the link.
The vehicle height changes approximately 2 mm (0.08 in.) by moving the link installation position by
1 mm (0.04 in.).
Page 909 of 4323
DIDCP±01
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±707
901 Author: Date:
2005 SEQUOIA (RM1146U)
HOW TO PROCEED WITH TROUBLESHOOTING
1 Vehicle Brought to Workshop
NEXT
2 Customer Problem Analysis (See page DI±710)
NEXT
3 Check CAN Communication System (See page DI±1065)
Check if any DTCs are output.
HINT:
The suspension control ECU of this system is connected to the CAN communication system. Therefore, be-
fore starting troubleshooting, make sure to check that there is no trouble in the CAN communication system.
CAN System DTC is Output (Proceed To ºCAN
COMMUNICATION SYSTEMº (See page
DI±1065))
No CAN System DTC is Output (Go to step 4)
4 Check and Clear DTCs (See page DI±723)
NEXT
5 Problem Symptom Confirmation
Symptom Does Not Occur (Go to step 6)
Symptom Occurs (Go to step 7)
Page 910 of 4323
DI±708
± DIAGNOSTICSAIR SUSPENSION SYSTEM
902 Author: Date:
2005 SEQUOIA (RM1146U)
6 Symptom Simulation (See page IN±35)
NEXT
7 DTC Check (See page DI±723), Test Mode (See page DI±711)
Normal System Code (Go to step 8)
Trouble Code (Go to step 9)
8 Problem Symptoms Table (See page DI±716)
NEXT Go To Step 10
9 DTC Chart (See page DI±729)
NEXT
10 Circuit Inspection (See page DI±731 to DI±793)
NEXT
11 Identification of Problem
NEXT
12 Repair
NEXT
Page 911 of 4323
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±709
903 Author: Date:
2005 SEQUOIA (RM1146U)
13 Confirmation Test
NEXT
End
HINT:
Step 4, 7, 10, 13:
Diagnostic steps permitting use of the hand±held tester.
Page 912 of 4323

DIDCS±01
Air Suspension System Check Sheet
:
Always
Once onlySometimes ( times per day, month) Inspector 's
Name
Customer 's Name
/ / Date Vehicle
Brought InOdometer Reading/ /
Frequency Problem Occurs
Weather
Outdoor Temperature
Symptoms Date Problem First Occurred
Place Conditions When
Problem OccurredCloudy Fine Rainy Snowy
Various/Other
Cool Warm Hot
Cold (Approx. °F ( °C))
Rough RoadInner City Hill (Up, Down)
Other Suburbs Highway
Vehicle height cannot be changed by operating the
height control switch
Normal System Code Malfunction in
vehicle height
control
Other ( ) High speed control does not operate
Trouble Code (Code )
Normal System Code Trouble Code (Code ) DTC Check
2nd Time 1st Time
Indicator lamp does
not come onHeight control manual indicator lamp does not come on
Height control indicator lamp does not come onLicence Plate No.VIN
Production Date
Otherkm
miles DI±710
± DIAGNOSTICSAIR SUSPENSION SYSTEM
904 Author: Date:
2005 SEQUOIA (RM1146U)
CUSTOMER PROBLEM ANALYSIS CHECK