height TOYOTA SEQUOIA 2001 Service Owner's Manual

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.

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

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.).

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

DIDCV±01
C00083
DLC3
CG TS
F16800
Height
Control
Manual
Indicator
Lamp
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±711
905 Author: Date:
2005 SEQUOIA (RM1146U)
TEST MODE PROCEDURE
1. INPUT SIGNAL CHECK (Using SST check wire)
HINT:

This function checks if signals from the stop light switch
assy and the door courtesy lamp switch, etc. are being in-
put normally to the ECU.

When entering test mode, the suspension control ECU
sets all the test mode DTCs first.
After completing the test mode for each check item, the
test mode DTCs that are determined normal by the sus-
pension control ECU will be erased.
The test mode DTCs for other check items may not be
erased when only a certain signal is inspected.

When the test mode returns back to normal mode, all the
test mode DTCs will be erased.
(a) Procedure for Input Signal Check Mode (Test Mode) us-
ing SST check wire.
SST 09843±18040
(1) Make sure the ignition switch is OFF.
(2) Set each of the check items to the condition shown
under Operation (A) in the test mode table on the
next page.
(3) Using SST, connect terminals TS and CG of the
DLC3.
(4) Turn the ignition switch to the ON position.
(5) Check that the height control manual indicator lamp
is blinking.
HINT:

The height control manual indicator lamp comes on for 2
seconds, then blinks at 0.25 sec. intervals.

If the height control manual indicator light does not blink,
inspect the height control manual indicator lamp circuit
(See page DI±789).

C00083
DLC3
CG TC
TS
F16800
Height
Control
Manual
Indicator
Lamp
DI±712
± DIAGNOSTICSAIR SUSPENSION SYSTEM
906 Author: Date:
2005 SEQUOIA (RM1146U)

The TS terminal circuit uses CAN (Controller Area Net-
work) for communication. Therefore, if there are any mal-
functions in the communication circuit, one or more DTCs
in the CAN communication system is/are output.
(6) Set each of the check items to the condition shown
under Operation (B) in the test mode table below.
HINT:
When checking each item, the height control manual indicator
lamp comes on for 1 second.
Test mode table:
Check ItemOperation (A)Operation (B)
Stop light switch signalOFF (Brake pedal not depressed)ON (Brake pedal depressed)
Door courtesy light switch signalON (Each door opened)OFF (All doors closed)
Height control switch signal±Press the height control switch ºUPº first and
then press ºDOWNº
Height control mode select switch signalOFF (Height control mode select switch not
pushed in)ON to OFF (Height control mode select switch
pushed in and released)
(7) Using SST, connect the 3rd terminal of the SST
check wire to terminal TC of the DLC3.
SST 09843±18040
(8) Read the number of blinks of the height control
manual indicator lamp.

A08841
Hand±held
Tester
DLC3
DI±714
± DIAGNOSTICSAIR SUSPENSION SYSTEM
908 Author: Date:
2005 SEQUOIA (RM1146U)
DTC of air suspension system test mode (input signal check) function:
If a trouble code is displayed during the test mode DTC check, check the circuit listed for that code. For details
of each code, refer to ºSee pageº under the respective DTC No. in the chart.
DTC No.
(See Page)Detection ItemTrouble Area
C1782/82
(DI±767)Stop light switch circuit malfunction

Stop light switch assy

Stop light switch circuit

Suspension control ECU
C1783/83
(DI±770)Door courtesy switch circuit malfunction

Door courtesy light switch assy

W/ Motor back door assy

Door courtesy light switch circuit

Body ECU

Back door ECU

Suspension control ECU
C1786/86
(DI±774)Height control switch circuit malfunction

Height control switch

Height control switch circuit

Suspension control ECU
C1788/88
(DI±778)Height control mode select switch circuit malfunction

Height control mode select switch

Height control mode select switch circuit

Suspension control ECU
2. INPUT SIGNAL CHECK (Using Hand±held Tester)
HINT:

This function checks if signals from the stop light switch
assy and the door courtesy lamp switch, etc. are being in-
put normally to the ECU.

When entering test mode, the suspension control ECU
sets all the test mode DTCs first.
After completing the test mode for each check item, the
test mode DTCs that are determined normal by the sus-
pension control ECU will be erased.
The test mode DTCs for other check items may not be
erased when only a certain signal is inspected.

When the test mode returns back to normal mode, all the
test mode DTCs will be erased.
(a) Procedure for Test Mode (Input signal check).
(1) Make sure that the ignition switch is off.
(2) Set each of the check items to the condition shown
under Operation (A) in the test mode table on the
next page.
(3) Connect the hand±held tester to the DLC3.
(4) Turn the ignition switch to the ON position.
(5) Select TEST MODE mode on the hand±held tester.
(6) Set each of the check items to the condition shown
under Operation (B) in the test mode table below.

± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±715
909 Author: Date:
2005 SEQUOIA (RM1146U)
Test mode (input signal check) table:
Check ItemOperation (A)Operation (B)
Stop light switch signalOFF (Brake pedal not depressed)ON (Brake pedal depressed)
Door courtesy light switch signalON (Each door opened)OFF (All doors closed)
Height control switch signal±Press the height control switch ºUPº first and
then press ºDOWNº
Height control mode select switch signalOFF (Height control mode select switch not
pushed in)ON to OFF (Height control mode select switch
pushed in and released)
HINT:
In step (6), all signals can be checked together.
(7) Read the test mode DTCs by following the prompts
on the tester screen.
HINT:
Refer to the hand±held tester operator's manual for further de-
tails.
(8) Check the malfunction using the code table below.
DTC of air suspension system test mode (input signal check) function:
If a trouble code is displayed during the test mode DTC check, check the circuit listed for that code. For details
of each code, refer to ºSee pageº under the respective DTC No. in the chart.
DTC No.
(See Page)Detection ItemTrouble Area
C1782/82
(DI±767)Stop light switch circuit malfunction

Stop light switch assy

Stop light switch circuit

Suspension control ECU
C1783/83
(DI±770)Door courtesy switch circuit malfunction

Door courtesy light switch assy

W/ Motor back door assy

Door courtesy light switch circuit

Body ECU

Back door ECU

Suspension control ECU
C1786/86
(DI±774)Height control switch circuit malfunction

Height control switch

Height control switch circuit

Suspension control ECU
C1788/88
(DI±778)Height control mode select switch circuit malfunction

Height control mode select switch

Height control mode select switch circuit

Suspension control ECU
(9) After completing the test mode, disconnect the tes-
ter and turn the ignition switch off.

DIDCZ±01
DI±716
± DIAGNOSTICSAIR SUSPENSION SYSTEM
910 Author: Date:
2005 SEQUOIA (RM1146U)
PROBLEM SYMPTOMS TABLE
HINT:

If a normal system code is displayed during the DTC check but the problem still occurs, check the cir-
cuits for each problem symptom in the order given in the table below and proceed to the relevant trou-
bleshooting page.

Inspect the fuse before inspecting the suspected areas as shown in the chart below.

Inspect each malfunction circuit in numerical order for the corresponding symptom.

If the malfunction still exists even after checking and confirming that all the circuits are normal, replace
the suspension control ECU.
SymptomSuspected AreaSee page
Vehicle height control function does not operate.
If the compressor remains on for an excessive period of
time or turns on and off repeatedly, the system control will
be halted for up to 70 minutes, after which the system will
return to normal operation.
1. Air tube is seized
2. Power source circuit
3. IG signal circuit
4. Crankshaft position sensor circuit
5. Height control mode select switch circuit
6. Height control switch circuit
7. Height control sensor circuit
8. Leveling solenoid valve circuit
9. Gate solenoid valve circuit
10.Exhaust solenoid valve circuit
11. AIR SUS relay circuit
12.Height control compressor circuit
13.Suspension control ECU
±
DI±761
DI±793
DI±210
DI±778
DI±774
DI±731
DI±740
DI±736
DI±744
DI±747
DI±752
IN±35
Illuminated position of height control indicator lamp does not
change by the height control switch operation.
1. Power source circuit
2. Crankshaft position sensor circuit
3. Height control mode select switch circuit
4. Height control switch circuit
5. Height control sensor circuit
6. Leveling solenoid valve circuit
7. Gate solenoid valve circuit
8. Exhaust solenoid valve circuit
9. AIR SUS relay circuit
10.Height control compressor circuit
11. Speed sensor circuit
12.CAN communication circuit
13.Suspension control ECUDI±763
DI±761
DI±793
DI±210
DI±778
DI±774
DI±731
DI±740
DI±736
DI±744
DI±783
DI±1065
IN±35
Hunting of vehicle height occurs.
1. Air leakage (Height control cylinder assy rear)
2. Height control sensor circuit
3. Suspension control ECUSA±156
DI±731
IN±35
Vehicle height control operates, but vehicle height is uneven.
1. Air leakage
2. Clogging of the air tube
3. Height control sensor link sub±assy
4. Height control sensor circuit
5. Gate solenoid valve circuit
6. Suspension control ECUSA±156
±
SA±156
DI±731
DI±736
IN±35
Vehicle height control operates, but vehicle height is high or
low (Vehicle height in NORMAL mode differs from the standard
value).1. Height control sensor link sub±assy
2. Height control sensor circuit
3. Suspension control ECUSA±156
DI±731
IN±35
When vehicle height control is adjusted, it stops at extremely high
or low position.1. Height control sensor circuit
2. Height control sensor link sub±assy
3. Suspension control ECUDI±731
SA±156
IN±35

± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±717
911 Author: Date:
2005 SEQUOIA (RM1146U) Height control manual indicator lamp condition is abnormal.
1. Power source circuit
2. Height control mode select switch circuit
3. Height control manual indicator lamp circuit
4. Suspension control ECUDI±763
DI±778
DI±789
IN±35
Height control indicator lamp condition is abnormal.
1. Power source circuit
2. Height control indicator lamp circuit
3. Suspension control ECUDI±763
DI±785
IN±35
DTC check cannot be completed.
1. Power source circuit
2. CAN communication system
3. Height control manual indicator lamp circuit
4. Suspension control ECU
5. ECMDI±763
DI±782
DI±789
IN±35
IN±35
Input signal check (test mode) cannot be completed.
1. Power source circuit
2. CAN communication system
3. Suspension control ECU
4. Translate ECUDI±763
DI±783
IN±35
IN±35
Vehicle height is extremely low when vehicle is parked.
Although, especially in a cold district, the vehicle height
may become lower due to a drop in air temperature in the
height control cylinder assy, but this is not abnormal.
1. Air leakage
2. Height control cylinder assy
3. Height control sensor link sub±assy
4. Leveling solenoid valve circuit
5. Exhaust valve circuit
SA±156
±
SA±156
DI±740
DI±744
Compressor motor continues to operate.
Due to the air tube freezing, vehicle height may not rise.
1. Air leakage
2. Air tube clogged
3. Height control cylinder assy
4. Height control sensor link sub±assy
5. Height control sensor circuit
6. Leveling solenoid valve circuit
7. Exhaust valve circuit
8. AIR SUS relay circuit
9. Height control compressor circuit
10.Suspension control ECU
SA±156
±
±
SA±156
DI±731
DI±740
DI±744
DI±747
DI±752
IN±35