Page 1521 of 4323
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±1319
1513 Author: Date:
2005 SEQUOIA (RM1146U)
8 Replace occupant classification ECU.
(a) Turn the ignition switch to the LOCK position.
(b) Disconnect the negative (±) terminal cable from the battery, and wait for at least 90 seconds.
(c) Replace the occupant classification ECU (see page RS±111).
NEXT
9 Perform zero point calibration.
(a) Connect the negative (±) terminal cable to the battery.
(b) Connect the hand±held tester to the DLC3.
(c) Turn the ignition switch to the ON position.
(d) Using the hand±held tester, perform ºZero point calibrationº (see page DI±1128).
OK:
The ºCOMPLETEDº is displayed.
NEXT
10 Perform sensitivity check.
Using the hand±held tester, perform ºSensitivity checkº (see page DI±1128).
OK:
Standard value: 27 to 33 kg (59.52 to 72.75 lb)
NEXT
END
Page 1522 of 4323

DI±1320
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1514 Author: Date:
2005 SEQUOIA (RM1146U)
DTC B1790 Airbag Sensor Assembly Communication
Circuit Malfunction
CIRCUIT DESCRIPTION
The airbag sensor assembly communication circuit consists of the occupant classification ECU and the air-
bag sensor assembly.
DTC B1790 is recorded when a malfunction is detected in the airbag sensor assembly communication cir-
cuit.
DTC No.DTC Detecting ConditionTrouble Area
B1790
The occupant classification ECU receives a line short
circuit signal, an open circuit signal, a short circuit to
ground signal or a short circuit to B+ signal in the airbag
sensor assembly communication circuit for 2 seconds.
Airbag sensor assembly malfunction
Occupant classification ECU malfunction
Occupant classification ECU
Airbag sensor assembly
Floor wire
Seat wire No. 1
HINT:
When DTC B1650/32 is detected as a result of troubleshooting for the supplemental restraint system, check
the DTCs stored in the occupant classification ECU. When DTC B1790 is output, perform troubleshooting
for the DTC.
DIDHD±01
Page 1523 of 4323
H02750
O6
Occupant Classification ECU
FSR+
BL13
WW
A2116Airbag Sensor Assembly
A2124
B B
BL15
FSR±FSR+
FSR± 8
4
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±1321
1515 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM
Page 1524 of 4323

DI±1322
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1516 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
HINT:
If troubleshooting (wire harness inspection) is difficult to perform, remove the passenger seat installa-
tion bolts to see the under surface of seat cushion.
In the above case, hold the seat so that it does not fall down. Holding the seat for a long period of time
may cause a problem, such as seat rail deformation. Hold the seat only as necessary.
1 Check DTC.
CHECK:
(a) Turn the ignition switch to the ON position.
(b) Clear the DTCs stored in memory (see page DI±1147).
HINT:
First clear DTCs stored in the occupant classification ECU and then in the airbag sensor assembly.
(c) Turn the ignition switch to the LOCK position.
(d) Turn the ignition switch to the ON position.
(e) Using the hand±held tester, check the DTCs of the occupant classification ECU (see page DI±1147).
OK:
DTC B1790 is not output.
HINT:
Codes other than DTC B1790 may be output at this time, but they are not related to this check.
NG Go to step 2.
OK
From the results of the above inspection, the malfunctioning part can now be considered normal.
To make sure of this, use the simulation method to check (see page DI±1137).
Page 1525 of 4323

± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±1323
1517 Author: Date:
2005 SEQUOIA (RM1146U)
2 Check connection of connectors.
PREPARATION:
(a) Turn the ignition switch to the LOCK position.
(b) Disconnect the negative (±) terminal cable from the battery, and wait for at least 90 seconds.
CHECK:
Check that the connectors are properly connected to the occupant classification ECU and the airbag sensor
assembly.
OK:
The connectors are connected securely.
NG Connect connectors, then go to step 1.
OK
3 Prepare for inspection.
PREPARATION:
CAUTION:
Be sure to perform the following procedures before troubleshooting to avoid unexpected airbag de-
ployment.
(a) Disconnect the connectors from the airbag sensor assembly.
(b) Disconnect the connectors from the steering wheel pad.
(c) Disconnect the connectors from the front passenger airbag assembly.
(d) w/ Side and curtain shield airbag:
Disconnect the connectors from the side airbag assembly LH and RH.
(e) w/ Side and curtain shield airbag:
Disconnect the connectors from the curtain shield airbag assembly LH and RH.
(f) Disconnect the connectors from the front seat outer belt LH and RH.
NEXT
Page 1526 of 4323

C84205G27650H24003
Occupant
Classification ECUAirbag
Sensor
Assembly
D
A21
FSR±FSR+CBA
E F
C84207G27650H43694H24002
Occupant
Classification ECUAirbag
Sensor
Assembly
D
FSR±FSR+ CBA
FSR+
FSR± O6
E F
A21
Service Wire
DI±1324
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1518 Author: Date:
2005 SEQUOIA (RM1146U)
4 Check airbag sensor assembly communication circuit (short to B+).
PREPARATION:
(a) Disconnect the connector from the occupant classifica-
tion ECU.
(b) Connect the negative (±) terminal cable to the battery.
CHECK:
(a) Turn the ignition switch to the ON position.
(b) Measure the voltage according to the value(s) in the table
below.
OK:
Tester ConnectionConditionSpecified Condition
A21±16 (FSR+) ±
Body groundIgnition switch ONBelow 1 V
A21±24 (FSR±) ±
Body groundIgnition switch ONBelow 1 V
NG Go to step 13.
OK
5 Check airbag sensor assembly communication circuit (open).
PREPARATION:
(a) Turn the ignition switch to the LOCK position.
(b) Disconnect the negative (±) terminal cable from the bat-
tery, and wait for at least 90 seconds.
(c) Using a service wire, connect O6±8 (FSR+) and O6±4
(FSR±) of connector ºEº.
NOTICE:
Do not forcibly insert a service wire into the terminals of the
connector when connecting.
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
Tester ConnectionConditionSpecified Condition
A21±16 (FSR+) ±
A21±24 (FSR±)AlwaysBelow 1 W
NG Go to step 14.
OK
Page 1527 of 4323
C84205G27650H24003
Occupant
Classification ECUAirbag
Sensor
Assembly
D
A21
FSR±FSR+CBA
E F
C84205G27650H24003
Occupant
Classification ECUAirbag
Sensor
Assembly
D
A21
FSR±FSR+CBA
E F
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±1325
1519 Author: Date:
2005 SEQUOIA (RM1146U)
6 Check airbag sensor assembly communication circuit (short).
PREPARATION:
Disconnect the service wire from connector ºEº.
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
Tester ConnectionConditionSpecified Condition
A21±16 (FSR+) ±
A21±24 (FSR±)Always1 MW or higher
NG Go to step 15.
OK
7 Check airbag sensor assembly communication circuit (short to ground).
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
Tester ConnectionConditionSpecified Condition
A21±16 (FSR+) ±
Body groundAlways1 MW or higher
A21±24 (FSR±) ±
Body groundAlways1 MW or higher
NG Go to step 16.
OK
Page 1528 of 4323

DI±1326
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1520 Author: Date:
2005 SEQUOIA (RM1146U)
8 Check DTC.
PREPARATION:
(a) Connect the connectors to the occupant classification ECU and the airbag sensor assembly.
(b) Connect the negative (±) terminal cable to the battery.
CHECK:
(a) Turn the ignition switch to the ON position.
(b) Clear the DTCs stored in memory (see page DI±1147).
HINT:
First clear DTCs stored in the occupant classification ECU and then in the airbag sensor assembly.
(c) Turn the ignition switch to the LOCK position.
(d) Turn the ignition switch to the ON position.
(e) Using the hand±held tester, check the DTCs of the occupant classification ECU (see page DI±1147).
OK:
DTC B1790 is not output.
HINT:
Codes other than DTC B1790 may be output at this time, but they are not related to this check.
NG Go to step 9.
OK
From the results of the above inspection, the malfunctioning part can now be considered normal.
To make sure of this, use the simulation method to check (see page DI±1137).