2001 TOYOTA SEQUOIA seat

H23981
Occupant
Classification Sensor
Occupant
Classification ECU
Occupant Load
A
A ± A Cross Section
Occupant
Classification Sensor
Occupant
Classification Sensor
A
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±1125
1319 Author: Date:
2005 SEQUOIA (RM1146U)
3. DESCRIPTION OF OCCUPANT CLASSIFICATION SYSTEM
(a) GENERAL DESCRIPTION.
(1) In the occupant classification system, the occupant classification ECU calculates the weight of
the occupant based on a signal from the occupant classification sensor. This system recognizes
the occupant to be a child if it detects a weight of less than 36 kg (79.37 lb), and disables the
front and side airbags.
(2) This system is mainly comprised of 4 occupant classification sensors that detect the load on the
front passenger seat. The occupant classification ECU controls the system, and the passenger
airbag ON/OFF indicator indicates the ON/OFF condition of the front passenger airbag assembly
and side airbag assembly (passenger side).
(b) OCCUPANT CLASSIFICATION SENSOR.
The occupant classification sensors are installed on 4 brackets connecting the seat rail and seat frame.
Accordingly, when load is applied to the passenger seat by an occupant sitting in it, the occupant classi-
fication sensors register a distortion.

DIDGK±01
A08841
Hand±held Tester
DLC3
DI±1128
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1322 Author: Date:
2005 SEQUOIA (RM1146U)
INITIALIZATION
ZERO POINT CALIBRATION AND SENSITIVITY CHECK
NOTICE:
Make sure that the seat is not occupied before performing
the operation.
HINT:
Perform the zero point calibration and sensitivity check if any of
the following conditions occur.

The occupant classification ECU is replaced.

Accessories (seatback tray and seat cover, etc.) are
installed.

The passenger seat is removed from the vehicle.

The passenger airbag ON/OFF indicator (ºOFFº) comes
on when the passenger seat is not occupied.

The vehicle is brought to the workshop for repair due to
an accident or a collision.
Zero point calibration and sensitivity check procedures.
HINT:
Make sure that zero point calibration has finished normally, and
then perform the sensitivity check.
(1) Adjust the seat position according to the table be-
low.
Adjustment ComponentPosition
Slide DirectionRearmost position
Reclining AngleUpright position
Headrest HeightLowest position
Lifter HeightLowest position
(2) Connect the hand±held tester to the DLC3.
(3) Turn the ignition switch to the ON position.
(4) Perform the zero point calibration by following the
prompts on the tester screen shown in 2 pages lat-
er.
HINT:
Refer to the hand±held tester operator's manual for further de-
tails.
OK:
The ºCOMPLETEº is displayed.

± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±1129
1323 Author: Date:
2005 SEQUOIA (RM1146U)
(5) Perform the sensitivity check by following the
prompts on the tester screen shown in 2 pages lat-
er.
(6) Confirm that the beginning sensor reading is within
the standard value.
OK:
Standard value: ±3.2 to 3.2 kg (±7 to 7 lb)
(7) Place a 30 kg (66.14 lb) weight (eg. a 30 kg (66.14
lb) of lead mass) onto the passenger seat.
(8) Confirm that the sensitivity is within the standard
value.
OK:
Standard value: 27 to 33 kg (59.52 to 72.75 lb)
HINT:

When performing the sensitivity check, use a solid metal
weight (the check result may not appear properly if the
weight made from liquid is used).

When the sensitivity deviates from the standard value, re-
tighten the bolts of the passenger seat taking care not to
deform the seat rail. After performing this procedure, if the
sensitivity is not within the standard value, replace the
front seat assembly RH.

When zero point calibration has not finished normally, re-
place the front seat assembly RH.

DIAGNOSTIC MENU
OCCUPANT DETECT
1: DATA LIST
2: DTC INFO
5: ZERO CALIBRATION
6: SENSITIVITY CHK 4: SNAPSHOT
NOTICE
Please confirm seat
position.
Slide: Max rear
Recline: Max upright
Headrest: Max down
Lifter: Max down
PRESS [ENTER] or [EXIT]NOTICE
Confirm that
nothing is placed
on the passenger
seat.
PRESS [ENTER] or [EXIT]
NOTICE
Do you wish to
start ºZERO
CALIBRATIONº?
PRESS [YES] or [NO]ZERO CALIBRATION
COMPLETED
Next, perform the
SENSITIVITY CHECK.
PRESS [ENTER]
ZERO POINT CALIBRATION PROCEDURE
º1: DIAGNOSISº ± º1: OBD/MOBDº ± ºMODEL YEARº ± ºMODEL SELECTION = SEQUOIAº ±
Select the option parts ± º9: OCCUPANT DETECTº ± Refer to the following screen flow.
ZERO CALIBRATION
FAILED
EEPROM writing error
Please check DTCs
PRESS [ENTER]ZERO CALIBRATION
FAILED
Failed to SECURITY
ACCESS.
PRESS [ENTER]Try again
ZERO CALIBRATION
FAILED
Sensor range
Front Left
PRESS [ENTER] over malfunction
Front Right
Rear Left
Rear Right±±±±[ ]
±±±±[ ]
±±±±[ ]
±±±±[ ]Sensor information is
expressed as OK, MAX or MIN
in [ ].
If MAX or MIN is displayed,
replace the front seat assembly RH. Perform sensitivity check.
Perform DTC check and repair. DI±1130
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1324 Author: Date:
2005 SEQUOIA (RM1146U)

SENSITIVITY CHECK PROCEDURE
º1: DIAGNOSISº ± º1: OBD/MOBDº ± ºMODEL YEARº ± ºMODEL SELECTION = SEQUOIAº ±
Select the option parts ± º9: OCCUPANT DETECTº ± Refer to the following screen flow.
DIAGNOSTIC MENU
OCCUPANT DETECT
1: DATA LIST
2: DTC INFO
5: ZERO CALIBRATION
6: SENSITIVITY CHK 4: SNAPSHOT
NOTICE
Please confirm
that nothing is
placed on the
passenger seat.
PRESS [ENTER] or [EXIT]SENSITIVITY CHECK
Beginning sensor
reading should be
±3.2 to 3.2 kg.
PRESS [ENTER]
SENSITIVITY CHECK
PRESS [ENTER]
(±7 to 7 lbs)
Sensor reading
0.00 kg
Place 30 kg (66 lbs)
weight on passenger
seat. Sensor reading
should be 27 to 33 kg.
(59 to 73 lbs)
Sensor reading
0.00 kg*1: kg @ lb
Unit can be changed based on unit conversion setting.
[System Selection Screen]
º1: DIAGNOSISº ± º9: SETUPº ± º4: UNIT CONVERSIONº
± ºWEIGHTº (kg @ lbs) (*1)
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±1131
1325 Author: Date:
2005 SEQUOIA (RM1146U)

DI6P2±15
DI±1132
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1326 Author: Date:
2005 SEQUOIA (RM1146U)
PROBLEM SYMPTOMS TABLE
Proceed with troubleshooting of each circuit in the table below.
SymptomSuspected AreaSee page

The front passenger seat condition differs from the indication by
the passenger airbag ON/OFF indicator (DTC is not output).
Trouble in indication of Passenger airbag ON/OFF indica-
torDI±1485

With the ignition switch is in ON position, the SRS warning light
sometimes comes on after approximately 6 seconds.
SRS warning light circuit (Always comes on, when DTC is
not output)DI±1491

The SRS warning light always comes on even when DTC is not
output.
SRS warning light circuit (Always comes on, when DTC is
not output)DI±1491

With the ignition switch is in the ON position, the SRS warning
light does not come on.
SRS warning light circuit (Does not come on, when igni-
tion switch is turned to the ON position)DI±1496

Although an SRS warning light operates normally, DTC or a
normal system code is not display.
TC terminal circuitDI±1498

Although terminals TC and CG of DLC3 are not connected, DTC
or a normal system code is display.
TC terminal circuitDI±1498

DIDGL±01
H24009
A19A20A21
17
24 18
23 19
22 20
21 4 8372615
12 13 11 14 10
15 9
16
28 27 26 25 30 294 8372615 4 8372615
10 9 12 13 11 14 15 16 10 9 12 13 11 14 15 16
17 18 19 20 24 23 22 21 17 18 19 20 24 23 22 21
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±1133
1327 Author: Date:
2005 SEQUOIA (RM1146U)
TERMINALS OF ECU
1. AIRBAG SENSOR ASSEMBLY
Terminal No.Terminal SymbolDestination
A19±1 (*1)SFL+Side airbag assembly LH (Side squib LH)
A19±2 (*1)SFL±Side airbag assembly LH (Side squib LH)
A19±3 (*1)ICL±Curtain shield airbag assembly LH (Curtain shield airbag LH
squib)
A19±4 (*1)ICL+Curtain shield airbag assembly LH (Curtain shield airbag LH
squib)
A19±5PL+Front seat outer belt LH (P/T squib LH)
A19±6PL±Front seat outer belt LH (P/T squib LH)
A19±9LSP+Seat position airbag sensor assembly
A19±10LBE+Front seat inner belt RH (Seat belt buckle switch LH)
A19±17LSP±Seat position airbag sensor assembly
A19±18LBE±Front seat inner belt RH (Seat belt buckle switch LH)
A19±19 (*1)VUPLSide airbag sensor assembly LH
A19±20 (*1)VUCLCurtain shield airbag sensor assembly LH
A19±21 (*1)ESLSide airbag sensor assembly LH
A19±22 (*1)ESCLCurtain shield airbag sensor assembly LH
A20±1P2+Front passenger airbag assembly (P squib (Dual stage ± 2nd
step))
A20±2P2±Front passenger airbag assembly (P squib (Dual stage ± 2nd
step))
A20±3P±Front passenger airbag assembly (P squib)
A20±4P+Front passenger airbag assembly (P squib)
A20±5D+Steering wheel pad (D squib)
A20±6D±Steering wheel pad (D squib)
A20±7D2±Steering wheel pad (D squib (Dual stage ± 2nd step))
A20±8D2+Steering wheel pad (D squib (Dual stage ± 2nd step))
A20±13PBEWIntegration control and panel (Seat belt warning light)
A20±14LACombination meter (SRS warning light)
A20±15TCDLC3

DI±1134
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1328 Author: Date:
2005 SEQUOIA (RM1146U)A20±16
SILDLC3
A20±17P±ABIntegration control and panel (Passenger airbag ON/OFF indi-
cator)
A20±18GSWBody ECU
A20±19 (*1)RMSWRSCA cutoff switch
A20±20 (*1)RMILCombination meter (RSCA OFF indicator)
A20±21IG2IGN1 Fuse (Power source)
A20±22GSW2ECM
A20±23PAONIntegration control and panel (Passenger airbag ON/OFF indi-
cator)
A20±25E1Ground
A20±26E2Ground
A20±27±SRFront airbag sensor RH
A20±28±SLFront airbag sensor LH
A20±29+SRFront airbag sensor RH
A20±30+SLFront airbag sensor LH
A21±3PR±Front seat outer belt RH (P/T squib RH)
A21±4PR+Front seat outer belt RH (P/T squib RH)
A21±5 (*1)ICR+Curtain shield airbag assembly RH (Curtain shield airbag RH
squib)
A21±6 (*1)ICR±Curtain shield airbag assembly RH (Curtain shield airbag RH
squib)
A21±7 (*1)SFR±Side airbag assembly RH (Side squib RH)
A21±8 (*1)SFR+Side airbag assembly RH (Side squib RH)
A21±16FSR+Occupant classification ECU
A21±19 (*1)ESCRCurtain shield airbag sensor assembly RH
A21±20 (*1)ESRSide airbag sensor assembly RH
A21±21 (*1)VUCRCurtain shield airbag sensor assembly RH
A21±22 (*1)VUPRSide airbag sensor assembly RH
A21±24FSR±Occupant classification ECU
*1: w/ Side and curtain shield airbag