TOYOTA SEQUOIA 2001 Service Repair Manual

± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±779
973 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
HINT:
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 ON, and turn the hand±held tester main switch ON.
(c) Select the item ºHEIGHT SW HOLDº in the DATA LIST, and read its value displayed on the hand±held
tester.
AIR SUSPENSION:
ItemMeasurement Item / Range (Dis-
play)Normal ConditionDiagnostic Note
HEIGHT SW HOLDHeight control mode select switch
/ ON or OFFON: Height control mode select
switch is pressed
OFF: ±
±
CHECK:
Check that the value displayed on the hand±held tester changes by pressing the height control mode select
switch.
OK:
Height control mode select switch 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

F19434
43
Height Control Mode Select Switch
Pushed In
Free
DI±780
± DIAGNOSTICSAIR SUSPENSION SYSTEM
974 Author: Date:
2005 SEQUOIA (RM1146U)
2 Inspect height control mode select switch.
PREPARATION:
Disconnect the height control mode select switch connector.
CHECK:
Check continuity between terminals 3 and 4 of the height con-
trol mode select switch when the height control mode select
switch is pushed in and free.
OK:
Switch conditionSpecification
Pushed inContinuity
FreeNo continuity
NG Replace height control mode select switch.
OK

F16805
Suspension Control ECU
Wire Harness View:
S25
TD
F19463
Height Control Mode Select Switch
Wire Harness Connector Front View:
H17
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±781
975 Author: Date:
2005 SEQUOIA (RM1146U)
3 Check harness and connector (Height control mode select switch ± Suspension
control ECU).
PREPARATION:
Disconnect the ECU connector.
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
Tester connection
(Symbol)ConditionSpecified condition
S25±12 (TD) ± H17±3AlwaysBelow 1 W
H17±4 ± Body groundAlwaysBelow 1 W
S25±12 (TD) ±
Body groundAlways10 kW or higher
NG Repair or replace harness or connector.
OK
Replace suspension control ECU
(See page IN±35).

DI±782
± DIAGNOSTICSAIR SUSPENSION SYSTEM
976 Author: Date:
2005 SEQUOIA (RM1146U)
DTC U0100/65 Lost Communication with ECM/PCM
CIRCUIT DESCRIPTION
The ECM sends signals such as engine speed signal, transmission signal, shift position signal, L4 switch
signal, TC terminal signal (diagnosis mode signal) to the suspension control ECU, etc. when the air suspen-
sion system is in operation.
DTC No.DTC Detecting ConditionTrouble Area
U0100/65
The suspension control ECU detects the following conditions
simultaneously:
1. Ignition switch ON
2. Vehicle speed signal is more than 30 km/h (18.5 mph)
3. No communication from ECM continues for more than 3
seconds

ECM

Suspension control ECU

Communication circuit
INSPECTION PROCEDURE
HINT:
This circuit uses CAN for communication. Therefore, if there are any malfunctions in the communication cir-
cuit, one or more DTCs in the CAN communication system is/are output.
1 Go to CAN communication system (See page DI±1065).
DIDEG±01

± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±783
977 Author: Date:
2005 SEQUOIA (RM1146U)
DTC U0122/67 Lost Communication with Translate ECU
CIRCUIT DESCRIPTION
The translate ECU sends signals such as vehicle wheel speed signal, TS terminal signal (test mode signal)
to the suspension control ECU, etc. when the air suspension system is in operation.
DTC No.DTC Detecting ConditionTrouble Area
U0122/67
The suspension control ECU detects the following conditions
simultaneously:
1. Ignition switch ON
2. No communication from translate ECU continues for more
than 3 seconds

Translate ECU

Suspension control ECU

Communication circuit
INSPECTION PROCEDURE
HINT:
This circuit uses CAN for communication. Therefore, if there are any malfunctions in the communication cir-
cuit, one or more DTCs in the CAN communication system is/are output.
1 Go to CAN communication system (See page DI±1065).
DIDEH±01

DI±784
± DIAGNOSTICSAIR SUSPENSION SYSTEM
978 Author: Date:
2005 SEQUOIA (RM1146U)
DTC U0132/71 Lost Communication with Ride Level Con-
trol Module
CIRCUIT DESCRIPTION
DTC No.DTC Detecting ConditionTrouble Area
U0132/71
The suspension control ECU detects the following conditions
simultaneously:
1. Ignition switch ON
2. No communication from CAN bus continues for more than
10 times

Suspension control ECU

Communication circuit
INSPECTION PROCEDURE
HINT:
This circuit uses CAN for communication. Therefore, if there are any malfunctions in the communication cir-
cuit, one or more DTCs in the CAN communication system is/are output.
1 Go to CAN communication system (See page DI±1065).
DIDEJ±01

F19450
C6
Combination
MeterSuspension Control
ECU
I18
Ignition SW Instrument Panel J/B
Engine Room J/B24
14
15
16 LO
N
HIP
B±L
GR±R26
S25
9
S25
8
S25LO
NR
HI
6
IG2 AM25
W±R B±R IGN1 11
7 1H
1J1C
1C32
W±R
AM2
1
2C
2D1
B
Battery B±O
B 5 4F10
FL Block
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±785
979 Author: Date:
2005 SEQUOIA (RM1146U)
Height Control Indicator Lamp Circuit
CIRCUIT DESCRIPTION
The height control indicator lamp indicates the target height, not the actual height.
It blinks when the height control is operated by pressing the height control switch and stays on when the
operation is completed.
WIRING DIAGRAM
DIDEL±01

DI±786
± DIAGNOSTICSAIR SUSPENSION SYSTEM
980 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Inspect height control indicator lamp.
PREPARATION:
Turn the ignition switch to the ON position.
CHECK:
Check that the height control indicator lamp comes on.
OK:
Height control indicator lamp comes on, and then goes off after 2 seconds.
NG Go to combination meter system
(See page DI±1610).
OK

I27705
Combination Meter Wire Harness View:
C6
C6±16
C6±15C6±14
F16805
Suspension Control ECU
Wire Harness View:
S25
NR HI
LO
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±787
981 Author: Date:
2005 SEQUOIA (RM1146U)
2 Check harness and connector (Suspension control ECU ± Combination meter
assy).
PREPARATION:
Disconnect the suspension control ECU connector and the
combination meter connector.
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
Tester connection
(Symbol)ConditionSpecified condition
S25±8 (HI) ± C6±16AlwaysBelow 1 W
S25±9 (NR) ± C6±15AlwaysBelow 1 W
S25±26 (LO) ± C6±14AlwaysBelow 1 W
S25±8 (HI) ± Body groundAlways10 kW or higher
S25±9 (NR) ±
Body groundAlways10 kW or higher
S25±26 (LO) ±
Body groundAlways10 kW or higher
NG Repair or replace harness or connector.
OK

F16805
Suspension Control ECU
Wire Harness View:
S25
NR HI
LO
DI±788
± DIAGNOSTICSAIR SUSPENSION SYSTEM
982 Author: Date:
2005 SEQUOIA (RM1146U)
3 Check combination meter.
PREPARATION:
Reconnect the combination meter connector.
CHECK:
Measure the voltage according to the value(s) in the table be-
low.
OK:
Tester connection
(Symbol)ConditionSpecified condition
S25±8 (HI) ± Body groundIgnition switch ON10 to 14 V
S25±9 (NR) ±
Body groundIgnition switch ON10 to 14 V
S25±26 (LO) ±
Body groundIgnition switch ON10 to 14 V
NG Replace combination meter.
OK
Replace suspension control ECU
(See page IN±35).