2001 TOYOTA SEQUOIA height

DIDD7±01
C00083DLC3
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±721
915 Author: Date:
2005 SEQUOIA (RM1146U)
DIAGNOSIS SYSTEM
1. DIAGNOSIS SYSTEM
(a) Inspect the battery voltage.
Battery voltage: 11 to 14 V
If voltage is below 11 V, recharge the battery before proceeding.
(b) Check DLC3.
The suspension control ECU uses the CAN system and
ISO 9141±2 for communication. The terminal arrange-
ment of the DLC3 complies with SAE J1962 and matches
the ISO 9141±2 format.
Verify the conditions listed in the table below:
Symbols (Terminal No.)Terminal DescriptionConditionSpecified Condition
SIL(7) ± SG(5)Bus º+º lineDuring communicationPulse generation
CG(4) ± Body groundChassis groundAlwaysBelow 1 W
SG(5) ± Body groundSignal groundAlwaysBelow 1 W
BAT(16) ± Body groundBattery positiveAlways11 to 14 V
CANH(6) ± CANL (14)HIGH±level CAN bus lineIG switch OFF54 to 67 W
CANH(6) ± Battery positiveHIGH±level CAN bus lineIG switch OFF1 MW or higher
CANH(6) ± CG(4)HIGH±level CAN bus lineIG switch OFF3 KW or higher
CANL(14) ± Battery positiveLOW±level CAN bus lineIG switch OFF1 MW or higher
CANL(14) ± CG(4)LOW±level CAN bus lineIG switch OFF3 KW or higher
HINT:
If the hand±held tester display shows UNABLE TO CONNECT
TO VEHICLE when the cable of the hand±held tester is con-
nected to the DLC3, the ignition switch is turned ON and the tes-
ter is operated, there is a problem on the vehicle side or tester
side.

If communication is normal when the tester is connected
to another vehicle, inspect the DLC3 on the original ve-
hicle.

If communication is still not possible when the tool is con-
nected to another vehicle, the problem is probably in the
tester itself, so consult the service department listed in the
tester 's instruction manual.
(c) DTCs (Normal mode)
(1) DTCs are memorized in the suspension control
ECU and read by using the SST check wire or the
hand±held tester (see page DI±723 for the proce-
dure of DTCs check).
SST 09843±18040
(d) Test mode (Input signal check)
(1) By switching from normal mode into test mode, you
can inspect the height control switch, height control
mode select switch, door courtesy lamp switch, and
stop lamp switch (see page DI±711).

F16799
DI±722
± DIAGNOSTICSAIR SUSPENSION SYSTEM
916 Author: Date:
2005 SEQUOIA (RM1146U)
(e) Check the indicator lamp.
(1) Turn the ignition switch to the ON position.
(2) Check that the height control manual indicator lamp
and the height control indicator lamp come on for 2
seconds.
If the indicator check result is not normal, proceed to trouble-
shooting for the height control indicator lamp circuit (See page
DI±785) and the height control manual indicator lamp circuit
(See page DI±789).

DIDDA±01
C00083
DLC3
CG TC
F16800
Height
Control
Manual
Indicator
Lamp
F16801
ON0.25 sec.
OFF
0.25 sec.
0.5 sec.
1.5 sec.4.5 sec. 2.5 sec.
0.5 sec. ON
OFF Normal:
Codes 13 and 33:
1.5 sec.
Repeat
C00083
DLC3
CG TC
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±723
917 Author: Date:
2005 SEQUOIA (RM1146U)
DTC CHECK / CLEAR
1. DTC CHECK (USING SST CHECK WIRE)
(a) Checking DTCs using the SST check wire.
SST 09843±18040
(1) Using the SST, connect terminals TC and CG of the
DLC3.
(2) Turn the ignition switch to the ON position.
(3) Read and record any DTCs from the height control
manual indicator lamp on the combination meter.
As examples, the blinking patterns of a normal sys-
tem code and codes 13 and 33 are shown on the
left.
HINT:

If the height control manual indicator lamp does not show
any DTC or a normal system code, inspect the height con-
trol manual indicator lamp circuit
(See page DI±789).

The TC terminal circuit uses CAN for communication.
Therefore, if there are any malfunctions in the commu-
nication circuit, one or more DTCs in the CAN commu-
nication system is/are output.

If 2 or more malfunctions are indicated at the same time,
the lowest numbered DTC is displayed first.
(4) Refer to the Diagnostic Trouble Code Chart (See
page DI±729) for DTC information.
(5) After completing the check, remove the SST check
wire from the DLC3.
SST 09843±18040
(b) Clearing the DTCs using the SST check wire.
SST 09843±18040
(1) Using SST, connect terminals TC and CG of the
DLC3.
(2) Turn the ignition switch to the ON position.

BR3890
D05981
Hand±held
Tester
DLC3
DI±724
± DIAGNOSTICSAIR SUSPENSION SYSTEM
918 Author: Date:
2005 SEQUOIA (RM1146U)
(3) Clear DTCs stored in the ECU by depressing the
brake pedal 8 times or more within 5 seconds.
(4) Check that the height control manual indicator lamp
shows a normal system code.
(5) Remove the SST check wire from the DLC3.
SST 09843±18040
HINT:
Disconnecting the battery cable during the operation will not
erase DTCs in the ECU.
2. DTC CHECK (USING HAND±HELD TESTER)
(a) Checking DTCs using the hand±held tester.
(1) Connect the hand±held tester to the DLC3.
(2) Turn the ignition switch to the ON position.
(3) Read DTCs by following the prompts on the tester
screen.
HINT:
Refer to the hand±held tester operator's manual for further de-
tails.
(b) Clearing the DTCs using the hand±held tester.
(1) Connect the hand±held tester to the DLC3
(2) Turn the ignition switch to the ON position.
(3) Erase the DTCs following the prompts on the tester
screen.
HINT:
Refer to the hand±held tester operator's manual for further de-
tails.

DIDDC±01
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±725
919 Author: Date:
2005 SEQUOIA (RM1146U)
FAIL±SAFE CHART
FAIL±SAFE FUNCTION
When a rear air suspension system malfunction is detected under normal control operation, the suspension
control ECU will suspend the switch control of the height control operation.
FAIL±SAFE CHART
DTC No.Malfunction ItemFail±safe OperationFail±safe Deactivation
Condition
C1714/14Malfunction in height
control sensor
Auto mode:
When the target vehicle height, just before fail, is higher than
ºNº, vehicle height is lowered for 20 seconds and then sys-
tem control shuts down.
Manual mode:
When the target vehicle height, just before switching to the
manual mode, is higher than ºNº, the switch operation to
lower vehicle height is available for only 20 seconds.
Return to normal condition.
C1733/33Open or short in gate
solenoid valveSystem control shuts down.Return to normal condition.
C1734/34Open or short in level-
ing solenoid valveSystem control shuts down.Return to normal condition.
C1735/35Open or short in ex-
haust solenoid valve
Auto mode:
After vehicle height is raised through control, the system
shuts down.
Manual mode:
When vehicle height is lower than ºNº, only the switch opera-
tion to raise vehicle height is available.
Return to normal condition.
C1741/41Open or short in AIR
SUS relay circuit
Auto mode:
After vehicle height is lowered through control, the system
shuts down.
Manual mode:
When vehicle height is higher than ºNº, only the switch op-
eration to lower vehicle height is available.
Return to normal condition.
C1742/42Lock in height control
compressor motor
Auto mode:
After vehicle height is lowered through control, the system
shuts down.
Manual mode:
When vehicle height is higher than ºNº, only the switch op-
eration to lower vehicle height is available.
After interrupting for 70 min-
utes, restart the control.
C1751/51
Powered continuously
or powered excessive-
ly in height control
compressor motor
Auto mode:
After vehicle height is lowered through control, the system
shuts down.
Manual mode:
When vehicle height is higher than ºNº, only the switch op-
eration to lower vehicle height is available.
After interrupting for 70 min-
utes, restart the control.
C1761/61Malfunction in suspen-
sion control ECUSystem control shuts down.Return to normal condition.
C1774/74Power voltage
droppedSystem control shuts down.Return to normal condition.
U0100/65Lost communication
with TL ECUSystem control continues.Return to normal condition.

DIDDE±01
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±727
921 Author: Date:
2005 SEQUOIA (RM1146U)
DATA LIST / ACTIVE TEST
1. DATA LIST
HINT:
By accessing the DATA LIST displayed by the hand±held tester, you can read the value of the switches and
sensors and so on without removing any parts. Reading the DATA LIST is the first step of troubleshooting
and is one method to shorten labor time.
(a) Connect the hand±held tester to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Following the display on the tester, read the DATA LIST.
AIR SUSPENSION:
ItemMeasurement Item / Range (Dis-
play)Normal ConditionDiagnostic Note
VEHICLE SPD
Vehicle speed reading / min.: 0
km/h (0 mph), max.: 255 km/h
(158 mph)
Actual vehicle speedSpeed indicated on the combina-
tion meter
FR WHEEL SPD
Wheel speed (Front right) reading /
min.: 0 km/h (0 mph), max.: 255
km/h (159 mph)
Actual vehicle speedSpeed indicated on the speedome-
ter
FL WHEEL SPD
Wheel speed (Front left) reading /
min.: 0 km/h (0 mph), max.: 255
km/h (159 mph)
Actual vehicle speedSpeed indicated on the speedome-
ter
IG VOLTAGEECU power supply voltage / min.:
0 V, max.: 25.5 VActual ECU power supply voltage:
10 to 14 V±
POWER VOLTAGE+B power source voltage / min.: 0
V, max.: 25.5 VActual battery power supply volt-
age: 10 to 14 V±
STEERING ANG
Steering angle sensor reading /
min.: ±49150.5 deg, max.: 49152
degActual steering angle /
Left turn: reading increases
Right turn: reading increasesZero point is set at the point when
battery is connected
ENGINE SPDCrankshaft position sensor read-
ing / min.: 0 rpm, max.: 25,500 rpmActual engine speedSpeed indicated on the combina-
tion meter
HEIGHT SW DOWNHeight control switch (DOWN) /
ON or OFFON: Height control switch
ºDOWNº button pressed
OFF: ±
±
HEIGHT SW UPHeight control switch (UP) / ON or
OFFON: Height control switch ºUPº
button pressed
OFF: ±
±
HEIGHT SW HOLDHeight control mode select switch
/ ON or OFFON: Height control mode select
switch pressed
OFF: ±
±
STOP LIGHT SWStop light switch / ON or OFFON: Brake pedal depressed
OFF: Brake pedal released±
DOOR SWDoor courtesy light switch / ON or
OFFON: Open each door
OFF: Close all doors±
L4 SW4LO switch / ON or OFFON: 2WD/4HI switch pressed
OFF: ±±
TSTS terminal / ON or OFFON: During test mode
OFF: Normal mode±
TCTC terminal / ON or OFFON: DTC recorded
OFF: No DTC recorded±
SOL SLRLHeight control valve solenoid (Lev-
elling solenoid valve) / ON or OFFON: Leveling solenoid operated
OFF: Leveling solenoid not oper-
ated
±
SOL SLRGHeight control valve solenoid
(Gate solenoid valve) / ON or OFFON: Gate solenoid operated
OFF: Gate solenoid not operated±

DI±728
± DIAGNOSTICSAIR SUSPENSION SYSTEM
922 Author: Date:
2005 SEQUOIA (RM1146U) MAIN RELAY
MAIN relay / ON or OFFON: MAIN relay operated
OFF: MAIN relay not operated±
MOTOR RELAYAIR SUS relay / ON or OFFON: Compressor operated
OFF: Compressor not operated±
RR HEIGHT
Right rear height control sensor
reading / min.: ±3276.7 mm
(±129.004 in.), max.: 3276.8 mm
(129.008 in.)
Always: 0 mm (0 in.)±
RL HEIGHT
Left rear height control sensor
reading / min.: ±3276.7 mm
(±129.004 in.), max.: 3276.8 mm
(129.008 in.)
2WD:
Min.: ±15 mm (±0.59 in.)
Max.: 40 mm (1.57 in.)
4WD:
Min.: ±30 mm (±1.18 in.)
Max.: 40 mm (1.57 in.)
±
#CODESNumber of DTC recorded / min.: 0,
max.: 255Min.: 0, Max.: XX±
2. ACTIVE TEST LIST
HINT:
Perform the ACTIVE TEST using the hand±held tester to operate the sensors, relays and solenoids without
removing any parts. Performing the ACTIVE TEST is the first step of troubleshooting and is one of the meth-
ods to shorten labor time. It is possible to display the DATA LIST during the ACTIVE TEST.
(a) Connect the hand±held tester to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Following the display on the tester, perform the ACTIVE TEST.
AIR SUSPENSION:
ItemVehicle Condition / Test DetailsDiagnostic Note
RR HEIGHTTurn height control switch / UP or DOWN±
LEVEL SOL REARTurn leveling solenoid valve / ON or OFFOperation sound of solenoid (clicking sound) can
be heard
GATE SOL REARTurn gate solenoid valve / ON or OFFOperation sound of solenoid (clicking sound) can
be heard
MOTOR RELAYTurn AIR SUS relay / ON or OFFOperation sound of motor can be heard

DIDDG±01
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±729
923 Author: Date:
2005 SEQUOIA (RM1146U)
DIAGNOSTIC TROUBLE CODE CHART
HINT:

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

If no abnormality is found when the parts are inspected, inspect the suspension control ECU.

If a trouble code is displayed during the DTC check, check the circuit listed for that code. For details
of each code, refer to the ºSee pageº under respective DTC No. in the DTC chart.
DTC No.
(See Page)Detection ItemTrouble Area
Manual
Indicator
Lamp*
1Memory*2
C1714/14
(DI±731)Open or short in left rear height
control sensor circuit
Height control sensor sub±assy

Height control sensor circuit

Suspension control ECU

C1733/33
(DI±736)Open or short in gate solenoid
valve circuit
Gate solenoid valve (Height control valve)

Gate solenoid valve (Height control valve) circuit

Suspension control ECU

C1734/34
(DI±740)Open or short in leveling sole-
noid valve circuit
Leveling solenoid valve (Height control valve)

Leveling solenoid valve (Height control valve) circuit

Suspension control ECU

C1735/35
(DI±744)Open or short in exhaust sole-
noid valve circuit
Exhaust solenoid valve (Height control compressor)

Exhaust solenoid valve (Height control compressor) circuit

Suspension control ECU

C1741/41
(DI±747)Open or short in AIR SUS relay
circuit
AIR SUS relay

AIR SUS relay circuit

Suspension control ECU

C1742/42
(DI±752)Lock, open or short in height
control compressor circuit
Height control compressor assy

Height control compressor circuit

Suspension control ECU

C1751/51*3
(DI±757)
Continuous electric current to
height control compressor circuit

Height control compressor assy

Height control compressor circuit

Height control sensor circuit

Height control sensor sub±assy

Relief valve

AIR SUS relay circuit

Air leakage from the air tube or each valve

Clogging in the air tube or each valve

Suspension control ECU
X
C1761/61
(DI±761)ECU malfunction

Power source circuit

Suspension control ECU

Communication circuit
 / X
C1774/74
(DI±763)Power source drop

Battery

Power source circuit

Suspension control ECU
XX
U0100/65
(DI±782)Lost communication with ECM/
PCM
ECM

Suspension control ECU

Communication circuit
XX
U0122/67
(DI±783)Lost communication with TL
ECU
Translate ECU

Suspension control ECU

Communication circuit
XX
U0132/71
(DI±784)Lost communication with ride
level control module
Suspension control ECU

Communication circuitXX