2001 TOYOTA SEQUOIA DLC3 Ts

DIDCI±01
F19438
Height Control Sensor
Sub±assy
Height Control Mode
Select Switch
Body ECU
Stop Light Switch
Front Door Courtesy
Light Switch (Driver)
Front Door Courtesy
Light Switch
(Passenger)
Rear Door Courtesy
Light Switch (LH)
Rear Door Courtesy
Light Switch (RH)
Back Door Courtesy
Light SwitchCombination Meter
Leveling Solenoid Valve
AIR SUS Relay
DLC3
ECM
Translate ECU Compressor/
Height Control Dryer
Exhaust Solenoid Valve Height Control Valve
Compressor Assy Gate Solenoid Valve IG
BBAT
SBL2
SHRL
SGL2VN
HI
NR
LO
TD
UPSW
DWSW
Door
STPSLRR
SLRL
RC
RM+
RM±
SLEX
SIL
CANH
CANL
CANSuspension
Control ECU Height Control Switch
GND From IG SwitchFrom Battery
From
Battery DI±698
± DIAGNOSTICSAIR SUSPENSION SYSTEM
892 Author: Date:
2005 SEQUOIA (RM1146U)
SYSTEM DIAGRAM

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.

F16802
0.25 sec. 0.5 sec.
ON
OFF
0.25 sec.4.5 sec.
ON
OFF1.5 sec. Normal:
Code 82:
0.5 sec.
Repeat
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±713
907 Author: Date:
2005 SEQUOIA (RM1146U)
HINT:

As examples, the blinking patterns of a normal system
code and code 82 are shown in the illustration.

If 2 or more malfunctions are indicated at the same time,
the lowest numbered code is displayed first.

When a DTC is not output, check the TC terminal circuit
on page DI±1567.
(9) Check the malfunction using the code table on the
next page.
(b) Ending the Input Signal Check Mode (Test Mode) using
SST check wire.
SST 09843±18040
(1) With the ignition switch OFF, disconnect the SST
check wire from the terminals of the DLC3 and then
turn the ignition switch to the ON position.
(c) Procedure for Sensor Test Mode (Test Mode) using the
hand±held tester.
(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
previous page.
(3) Connect the hand±held tester to the DLC3.
(4) Turn the ignition switch to the ON position.
(5) Select SIGNAL CHECK 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 on the
previous page.
HINT:
In step (6), all signals can be checked together.
(7) Read the DTCs by following the prompts on the tes-
ter screen.
HINT:
Refer to the hand±held tester operator's manual for further de-
tails.

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.

F16807
GND
F19430
GND
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±719
913 Author: Date:
2005 SEQUOIA (RM1146U) RM+ (S25±20) ±
GND (S25±22)
R±L ± W±B
Height Control
Compressor
Motor Lock (+)Engine idling, vehicle height changes from ºNORMALº to
ºHIGHº by pressing the height control switch (While
height control compressor assy is working).
Below 1.0 V
RM± (S25±21) ±
Body groundBR±Y ± W±B
Height Control
Compressor
Motor Lock (±)
AlwaysBelow 1.0 V
GND (S25±22) ±
Body groundW±B ±
Body groundGroundAlwaysBelow 1.0 V
B (S25±24) ±
GND (S25±22)V ± W±BBatteryIG switch ON10 to 14 V
LO (S25±26) ± PWB
Height Control
I di t ºLOº
Engine idling, vehicle height is ºNORMALº "
P i th ºDOWNº b tt f th h i ht t l it h10 V or more "LO (S25 26)
GND (S25±22)P ± W±BIndicator ºLOº
SignalPressing the ºDOWNº button of the height control switch
turns on the ºLOº indicator lamp (*1)10 V or more "
Below 5 V
STP (S25±27) ± GY WBStop LightBk dld dRl d10 to 14 V "STP (S25 27)
GND (S25±22)G±Y ± W±BSto Light
SwitchBrake pedal depressed " Released10 to 14 V "
Below 1.5 V
SIL (S25±30) ±
GND (S25±22)G±R ± W±BDiagnosis Sig-
nalHand±held tester is connected to DLC3Pulse generation
(See waveform 3)
DOOR (S25±31) ± RWBDSilIG switch ON, each door opened "Below 1.5 VDOOR (S25 31)
GND (S25±22)R ± W±BDoor SignalIG switch ON, each door o ened "
All door closed
Below 1.5 V
10 to 14 V
DNSW (S25±32) ±
GND (S25±22)W ± W±B
Height Control
Switch
ºDOWNº SignalIG switch ON, ºDOWNº button of height control switch
pushed in "
ºDOWNº button of height control switch releasedBelow 1.5 V "
10 to 14 V
BAT (S25±25) ±
GND (S25±22)V ± W±BBatteryAlways10 to 14 V
CANL (S25±28) ±
GND (S25±22)W ± W±BCAN Commu-
nication SignalIG switch ONPulse generation
(See waveform 1)
CANH (S25±29) ±
GND (S25±22)G ± W±BCAN Commu-
nication SignalIG switch ONPulse generation
(See waveform 2)
*1: Perform inspection after checking that the height control indicator lamp switches are illuminated when
the height control switch button is pressed.
Waveform 1 (Reference):
ItemContents
TerminalCANL ± GND
Tool setting1V/DIV, 10ms/DIV
Vehicle conditionIgnition SW ON, Engine stopped
Waveform 2 (Reference):
ItemContents
TerminalCANH ± GND
Tool setting1V/DIV, 10ms/DIV
Vehicle conditionIgnition SW ON, Engine stopped

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).

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.