air suspension TOYOTA SEQUOIA 2001 Service Repair Manual

IN01T±18
± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN±23
23 Author: Date:
HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS
GENERAL INFORMATION
A large number of ECU controlled systems are used in the SEQUOIA. In general, the ECU controlled system
is considered to be a very intricate system requiring a high level of technical knowledge and expert skill to
troubleshoot. However, the fact is that if you proceed to inspect the circuits one by one, troubleshooting of
these systems is not complex. If you have adequate understanding of the system and a basic knowledge
of electricity, accurate diagnosis and necessary repair can be performed to locate and fix the problem. This
manual is designed through emphasis of the above standpoint to help service technicians perform accurate
and effective troubleshooting, and is compiled for the following major ECU controlled systems:
The troubleshooting procedure and how to make use of it are described on the following pages.
SystemPage
1. EngineDI±1
2. Automatic TransmissionDI±515
3. Air Suspension Control SystemDI±695
4. Tire Pressure Warning SystemDI±796
5. ABS with EBD & BA & TRAC & VSC SystemDI±891
6. Can Communication SystemDI±1060
7. Supplemental Restraint SystemDI±1118
8. Power Seat Control System w/ Driving Position MemoryDI±1501
9. Cruise Control SystemDI±1536
10.Engine Immobilizer SystemDI±1570
11. Combination Meter SystemDI±1601
12.Sliding Roof SystemDI±1661
13.Body Control SystemDI±1678
14.Driver Door Control SystemDI±1778
15.Passenger Door Control SystemDI±1814
16.Back Door Control SystemDI±1850
17.Multiplex Communication SystemDI±1887
18.Audio SystemDI±1955
19.Rear Seat Audio SystemDI±2044
20.Rear Seat Entertainment SystemDI±2078
21.Navigation SystemDI±2159
22.Air Conditioning SystemDI±2297
FOR USING OBD II SCAN TOOL OR TOYOTA HAND±HELD TESTER

Before using the scan tool or tester, the scan tool's instruction book or tester's operator manual should
be read thoroughly.

If the scan tool or tester cannot communicate with ECU controlled systems when you have connected
the cable of the scan tool or tester to DLC3, turned the ignition switch ON and operated the scan tool,
there is a problem on the vehicle side or tool side.
(1) If communication is normal when the tool is connected to another vehicle, inspect the diagnosis
data link line (Bus
line) or ECU power circuit of the vehicle.
(2) If communication is still not possible when the tool is connected to another vehicle, the problem
is probably in the tool itself, so perform the Self Test procedures outline in the Tester Operator's
Manual.

IN±26± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
26 Author: Date:
2005 SEQUOIA (RM1146U)
2. SYMPTOM CONFIRMATION AND DIAGNOSTIC TROUBLE CODE CHECK
The diagnostic system in the SEQUOIA fulfills various functions. The first function is the Diagnostic Trouble
Code Check in which a malfunction in the signal circuits to the ECU is stored in code in the ECU memory
at the time of occurrence, to be output by the technician during troubleshooting. Another function is the Input
Signal Check which checks if the signals from various switches are sent to the ECU correctly.
By using these check functions, the problem areas can be narrowed down quickly and troubleshooting can
be performed effectively. Diagnostic functions are incorporated in the following systems in the SEQUOIA.
SystemDiagnostic Trouble
Code CheckInput Signal Check
(Sensor Check)Diagnostic Test
Mode (Active Test)
1. Engine(with Check
Mode)
2. Automatic Transmission(with Check
Mode)
3. Air Suspension Control System(with Check
Mode)
4. Tire Pressure Warning System
5. ABS with EBD & BA & TRAC & VSC System
6. Can Communication System
7. Supplemental Restraint System(with Check
Mode)
8. Power Seat Control System w/ Driving Position Memory
9. Cruise Control System
10.Engine Immobilizer System
11. Combination Meter System
12.Sliding Roof System
13.Body Control System
14.Driver Door Control System
15.Passenger Door Control System
16.Back Door Control System
17.Multiplex Communication System
18.Audio System
19.Rear Seat Audio System
20.Rear Seat Entertainment System
21.Air Conditioning System
In diagnostic trouble code check, it is very important to determine whether the problem indicated by the diag-
nostic trouble code is still occurring or occurred in the past but returned to normal at present. In addition,
it must be checked in the problem symptom check whether the malfunction indicated by the diagnostic
trouble code is directly related to the problem symptom or not. For this reason, the diagnostic trouble codes
should be checked before and after the symptom confirmation to determine the current conditions, as shown
in the table on the next page. If this is not done, it may, depending on the case, result in unnecessary trouble-
shooting for normally operating systems, thus making it more difficult to locate the problem, or in repairs not
pertinent to the problem. Therefore, always follow the procedure in correct order and perform the diagnostic
trouble code check.

IN04Q±33
IN±40
± INTRODUCTIONTERMS
40 Author: Date:
2005 SEQUOIA (RM1146U)
TERMS
ABBREVIATIONS USED IN THIS MANUAL
AbbreviationsMeaning
ABSAnti±Lock Brake System
A/CAir Conditioner
ACAlternating Current
ACCAccessory
ACISAcoustic Control Induction System
ACMActive Control Engine Mount
ACSDAutomatic Cold Start Device
A.D.D.Automatic Disconnecting Differential
A/FAir±Fuel Ratio
AHCActive Height Control Suspension
ALRAutomatic Locking Retractor
ALTAlternator
AMPAmplifier
ANTAntenna
APPROX.Approximately
ASSYAssembly
A/T, ATMAutomatic Transmission (Transaxle)
AT FAutomatic Transmission Fluid
AUTOAutomatic
AUXAuxiliary
AV GAverage
AV SAdaptive Variable Suspension
B+Battery Voltage
BABrake Assist
BACSBoost Altitude Compensation System
BATBattery
BDCBottom Dead Center
B/LBi±Level
B/SBore±Stroke Ratio
BTDCBefore Top Dead Center
BVSVBimetallic Vacuum Switching Valve
CBCircuit Breaker
CCoCatalytic Converter For Oxidation
CCVCanister Closed Valve
CDCompact Disc
CFCornering Force
CGCenter Of Gravity
CHChannel
CKDComplete Knock Down
COMB.Combination
CPECoupe
CPSCombustion Pressure Sensor
CPUCentral Processing Unit
CRSChild Restraint System
CTRCenter
C/VCheck Valve
CVControl Valve
CWCurb Weight

± PREPARATIONSUSPENSION AND AXLE
PP±49
107 Author: Date:
2005 SEQUOIA (RM1146U)
(09710±03051)Bushing ReplacerFront axle
Front suspension
09730±00010Tube RemoverElectronic modulated air suspension
Height control valve
09843±18040Diagnosis Check Wire No.2Tire pressure monitor valve
09922±10010Variable Open WrenchFront suspension
09950±00020Bearing RemoverFront drive shaft
Front differential
Front suspension
Rear differential
09950±30012Puller A Set
(09951±03010)Upper PlateFront differential
Rear differential
(09953±03010)Center BoltFront differential
Rear differential
(09954±03010)ArmFront differential
Rear differential
(09955±03030)Lower Plate 130Front differential
Rear differential
(09956±03020)Adapter 18Front differential
(09956±03050)Adapter 24Rear differential
09950±40011Puller B Set

SS0OJ±22
± SERVICE SPECIFICATIONSSUSPENSION AND AXLE
SS±31
173 Author: Date:
2005 SEQUOIA (RM1146U)
SUSPENSION AND AXLE
SERVICE DATA
Tire size: P245/70R16 Front
Rear220 kPa (2.2 kgf/cm2, 32 psi)
240 kPa (2.4 kgf/cm2, 35 psi)
Cold tire inflation
pressureTire size: P265/70R16 Front
Rear220 kPa (2.2 kgf/cm2, 32 psi)
220 kPa (2.2 kgf/cm2, 32 psi)ressure
Tire size: P265/65R17 Front
Rear220 kPa (2.2 kgf/cm2, 32 psi)
220 kPa (2.2 kgf/cm2, 32 psi)
Vehicle height (Except air suspension models)
UCK35L±GKBSKA
Tire size: P245/70R16 Front:
A*1 ± B*2
Rear: C*3 ± D*4
Tire size: P265/70R16 and P265/65R17
Front:
A*1 ± B*2
Rear: C*3 ± D*4
69.7 mm (2.74 in.)
76.2 mm (3.00 in.)
69.5 mm (2.74 in.)
75.5 mm (2.97 in.)
UCK35L±GKBLKA Front:
A*1 ± B*2
Rear: C*3 ± D*471.6 mm (2.82 in.)
77.3 mm (3.04 in.)
UCK45L±GKBSKA Front:
A*1 ± B*2
Rear: C*3 ± D*461.6 mm (2.43 in.)
63.8 mm (2.51 in.)
Front wheel
UCK45L±GKBLKA Front:
A*1 ± B*2
Rear: C*3 ± D*462.8 mm (2.47 in.)
65.2 mm (2.57 in.)
Front wheel
Alignment
Vehicle height (Except air suspension models)g
UCK35L±GKBSKA
Tire size: P245/70R16 Front:
A*1 ± B*2
Rear: C*3 ± D*4
Tire size: P265/70R16 and P265/65R17
Front:
A*1 ± B*2
Rear: C*3 ± D*4
53.5 ± 83.5 mm (2.11 ± 3.29 in.)
74.8 ± 104.8 mm (2.94 ± 4.13 in.)
53.3 ± 83.3 mm (2.10 ± 3.28 in.)
74.1 ± 104.1 mm (2.92 ± 4.10 in.)
UCK35L±GKBLKA Front:
A*1 ± B*2
Rear: C*3 ± D*455.3 ± 85.3 mm (2.18 ± 3.36 in.)
74.6 ± 104.6 mm (2.94 ± 4.12 in.)
UCK45L±GKBSKA Front:
A*1 ± B*2
Rear: C*3 ± D*445.5 ± 75.5 mm (1.79 ± 2.97 in.)
61.0 ± 91.0 mm (2.40 ± 3.58 in.)
UCK45L±GKBLKA Front:
A*1 ± B*2
Rear: C*3 ± D*446.8 ± 76.8 mm (1.84 ± 3.02 in.)
61.3 ± 91.3 mm (2.41 ± 3.59 in.)
A*1: Ground clearance of the front drive shaft center
B*
2: Ground clearance of the front adjusting cam bolt center
C*
3: Ground clearance of the rear axle shaft center
D*
4: Ground clearance of the rear lower control arm front bolt center

SS±32
± SERVICE SPECIFICATIONSSUSPENSION AND AXLE
174 Author: Date:
2005 SEQUOIA (RM1146U)
CamberRight±left error: 30' (0.5°) or less
UCK35L±GKBSKA0°08' ± 45' (0.14° ± 0.75°)
UCK35L±GKBLKA0°06' ± 45' (0.10° ± 0.75°)
UCK45L±GKBSKA0°17' ± 45' (0.28° ± 0.75°)
UCK45L±GKBLKA0°16' ± 45' (0.26° ± 0.75°)
Caster (Except air suspension models) Right±left error: 30' (0.5°) or less
UCK35L±GKBSKA
Tire size: P245/70R16
Tire size: P265/70R16 and P265/65R17
2°56' ± 45' (2.93° ± 0.75°)
2°59' ± 45' (2.98° ± 0.75°)
UCK35L±GKBLKA3°02' ± 45' (3.04° ± 0.75°)
UCK45L±GKBSKA2°36' ± 45' (2.60° ± 0.75°)
UCK45L±GKBLKA2°38' ± 45' (2.64° ± 0.75°)
Caster (Air suspension models) Right±left error: 30' (0.5°) or less
UCK35L±GKBSKA
Tire size: P245/70R16
Tire size: P265/70R16 and P265/65R17
3°17' ± 45' (3.28° ± 0.75°)
3°20' ± 45' (3.33° ± 0.75°)
UCK35L±GKBLKA3°21' ± 45' (3.35° ± 0.75°)
UCK45L±GKBSKA2°55' ± 45' (2.91° ± 0.75°)
UCK45L±GKBLKA2°56' ± 45' (2.93° ± 0.75°)
Steering axis inclination Right±left error: 30' (0.5°) or less
Front wheel
AlignmentUCK35L±GKBSKA10°14' ± 45' (10.24° ± 0.75°)AlignmentUCK35L±GKBLKA10°16' ± 45' (10.27° ± 0.75°)
UCK45L±GKBSKA10°05' ± 45' (10.09° ± 0.75°)
UCK45L±GKBLKA10°07' ± 45' (10.11° ± 0.75°)
Toe±in (total) Rack end length difference: 1.5 mm (0.059 in.) or less
UCK35L±GKBSKA
Tire size: P245/70R16
Tire size: P265/70R16 and P265/65R17
Tire size: P265/65R17 (Air suspension models)
0°05' ± 0°09' (0.09° ± 0.15°, 1.19 ± 2 mm (0.05 ± 0.08 in.)
0°05' ± 0°09' (0.09° ± 0.15°, 1.29 ± 2 mm (0.05 ± 0.08 in.)
0°05' ± 0°09' (0.09° ± 0.15°, 1.28 ± 2 mm (0.05 ± 0.08 in.)
UCK35L±GKBLKA0°05' ± 0°09' (0.08° ± 0.15°, 1.15 ± 2 mm (0.05 ± 0.08 in.)
UCK45L±GKBSKA
Tire size: P265/70R16 (Air suspension models)0°05' ± 0°09' (0.08° ± 0.15°, 1.08 ± 2 mm (0.04 ± 0.08 in.)
0°05' ± 0°09' (0.08° ± 0.15°, 1.07 ± 2 mm (0.04 ± 0.08 in.)
UCK45L±GKBLKA0°04' ± 0°09' (0.07° ± 0.15°, 0.99 ± 2 mm (0.04 ± 0.08 in.)
UCK35L±GKSSKAInside wheel
Outside wheel: Reference
Outside wheel (Air suspension models): Reference-35°24' (-35.40°)
32°08' (32.13°)
31°54' (31.90°)
UCK35L±GKSLKAInside wheel
Outside wheel: Reference-35°22' (-35.36°)
32°07' (32.12°)
UCK45L±GKSSKAInside wheel
Outside wheel: Reference-35°37' (-35.61°)
32°17' (32.28°)
UCK45L±GKSLKAInside wheel
Outside wheel: Reference-35°35' (-35.59°)
32°16' (32.26°)
Front drive shaftFront drive shaft length523.5 ± 2.0 mm (20.610 ± 0.079 in.)
Upper ball joint turning torque0.7 ± 4.4 N´m (7 ± 45 kgf´cm, 6 ± 39 in.´lbf)
Ft iLower ball joint excessive play Maximum0.5 mm (0.020 in.)Front suspensionLower ball joint turning torque1.0 ± 6.5 N´m (10 ± 66 kgf´cm, 9 ± 56 in.´lbf)
Stabilizer bar link ball joint turning toque0.05 ± 2.0 N´m (0.5 ± 20 kgf´cm, 0.4 ± 17 in.´lbf)

SS±38
± SERVICE SPECIFICATIONSSUSPENSION AND AXLE
180 Author: Date:
2005 SEQUOIA (RM1146U)
Air suspension
Amount of change in vehicle height
HIGH position:
LOW position (4WD):
LOW position (2WD):
40 mm (1.57 in.)
±30 mm (±1.18 in.)
±15 mm (±0.59 in.)
Air suspension
Difference between the tester value and vehicle height
(D±C measurement):
5 mm (0.20 in.) or less
Height control sensor link standard length:6.5 ± 15.0 mm (0.26 ± 0.59 in.) or less

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)