TOYOTA SEQUOIA 2001 Service Repair Manual

C84211H24024H24005
Occupant
Classification
ECU
Airbag
Sensor
Assembly
A
FSR+
FSR± B C D E F
BL1Seat Wire No. 1
Floor Wire
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±1329
1523 Author: Date:
2005 SEQUOIA (RM1146U)
13 Check seat wire No. 1 (short to B+).
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 for 90 seconds.
(c) Disconnect the seat wire No. 1 connector from the floor
wire.
(d) Connect the negative (±) terminal cable to the battery,
and wait for at least 2 seconds.
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
BL1±3 (FSR+) ±
Body groundIgnition switch ONBelow 1 V
BL1±5 (FSR±) ±
Body groundIgnition switch ONBelow 1 V
NG Repair or replace seat wire No. 1.
OK
Repair or replace floor wire.

C84213
H43694H24024H24004
Occupant
Classification
ECUAirbag
Sensor
Assembly
A
O6
FSR+FSR±B C D E F
Service Wire
BL1
Seat Wire No. 1
Floor Wire
FSR+
FSR±
C84211H24024H24005
Occupant
Classification
ECU
Airbag
Sensor
Assembly
A
FSR+
FSR± B C D E F
BL1Seat Wire No. 1
Floor Wire
DI±1330
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1524 Author: Date:
2005 SEQUOIA (RM1146U)
14 Check seat wire No. 1 (open).
PREPARATION:
Disconnect the seat wire No. 1 connector from the floor wire.
HINT:
The service wire has already been inserted into connector ºEº.
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
Tester ConnectionConditionSpecified Condition
BL1±3 (FSR+) ±
BL1±5 (FSR±)AlwaysBelow 1 W
NG Repair or replace seat wire No. 1.
OK
Repair or replace floor wire.
15 Check seat wire No. 1 (short).
PREPARATION:
Disconnect the seat wire No. 1 connector from the floor wire.
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
Tester ConnectionConditionSpecified Condition
BL1±3 (FSR+) ±
BL1±5 (FSR±)Always1 MW or higher
NG Repair or replace seat wire No. 1.
OK
Repair or replace floor wire.

C84211H24024H24005
Occupant
Classification
ECU
Airbag
Sensor
Assembly
A
FSR+
FSR± B C D E F
BL1Seat Wire No. 1
Floor Wire
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±1331
1525 Author: Date:
2005 SEQUOIA (RM1146U)
16 Check seat wire No. 1 (short to ground).
PREPARATION:
Disconnect the seat wire No. 1 connector from the floor wire.
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
Tester ConnectionConditionSpecified Condition
BL1±3 (FSR+) ±
Body groundAlways1 MW or higher
BL1±5 (FSR±) ±
Body groundAlways1 MW or higher
NG Repair or replace seat wire No. 1.
OK
Repair or replace floor wire.

DI±1332
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1526 Author: Date:
2005 SEQUOIA (RM1146U)
DTC B1793 Occupant Classification Sensor Power
Supply Circuit Malfunction
CIRCUIT DESCRIPTION
The occupant classification sensor power supply circuit consists of the occupant classification ECU and the
occupant classification sensors.
DTC B1793 is recorded when a malfunction is detected in the occupant classification sensor power supply
circuit.
DTC No.DTC Detecting ConditionTrouble Area
B1793

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 .

Occupant classification ECU malfunction
Front seat assembly RH (Occupant classification sensors)

Occupant classification ECU

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 B1793 is output, perform troubleshooting
for the DTC.
DIDHE±01

H24041
Occupant
Classification ECU
O7 SVC111
1 O8
Occupant Classification
Sensor Front LH
V
O7 SVC212
O7 SVC35
O7 SVC46 P
Y±B
Y 1
1
1 O9
Occupant Classification
Sensor Front RH
O10
Occupant Classification
Sensor Rear LH
O11
Occupant Classification
Sensor Rear RHSVC1
SVC2
SVC3
SVC4
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±1333
1527 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM

DI±1334
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1528 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 B1793 is not output.
HINT:
Codes other than DTC B1793 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).

H23821
SVC1SVC2 SVC4 SVC3
O7 Occupant Classification ECU:
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±1335
1529 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 occupant clas-
sification sensors.
OK:
The connectors are connected securely.
NG Connect connectors, then go to step 1.
OK
3 Check seat wire No. 1 (short to B+).
PREPARATION:
(a) Disconnect the connector from the occupant classifica-
tion ECU and the 4 occupant classification sensors.
(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
O7±5 (SVC3) ±
Body groundIgnition switch ONBelow 1 V
O7±6 (SVC4) ±
Body groundIgnition switch ONBelow 1 V
O7±11 (SVC1) ±
Body groundIgnition switch ONBelow 1 V
O7±12 (SVC2) ±
Body groundIgnition switch ONBelow 1 V
NG Repair or replace seat wire No. 1.
OK

H23821H43699H24595
SVC1SVC2 SVC4 SVC3
O7 Occupant Classification ECU:
O8
O9
O10
O11SVC1
SVC2
SVC3
SVC4 Occupant Classification Sensor
Front LH:
Occupant Classification Sensor
Front RH:
Occupant Classification Sensor
Rear LH:
Occupant Classification Sensor
Rear RH:
DI±1336
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1530 Author: Date:
2005 SEQUOIA (RM1146U)
4 Check seat wire No. 1 (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.
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
Tester ConnectionConditionSpecified Condition
O8±1 (SVC1) ±
O7±11 (SVC1)AlwaysBelow 1 W
O9±1 (SVC2) ±
O7±12 (SVC2)AlwaysBelow 1 W
O10±1 (SVC3) ±
O7±5 (SVC3)AlwaysBelow 1 W
O11±1 (SVC4) ±
O7±6 (SVC4)AlwaysBelow 1 W
NG Repair or replace seat wire No. 1.
OK

H23821
SVC1SVC2 SVC4 SVC3
O7 Occupant Classification ECU:
H23821
SVC1SVC2 SVC4 SVC3
O7 Occupant Classification ECU:
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±1337
1531 Author: Date:
2005 SEQUOIA (RM1146U)
5 Check seat wire No. 1 (short).
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
Tester ConnectionConditionSpecified Condition
O7±5 (SVC3) ±
O7±6 (SVC4)Always1 MW or higher
O7±6 (SVC4) ±
O7±11 (SVC1)Always1 MW or higher
O7±11 (SVC1) ±
O7±12 (SVC2)Always1 MW or higher
O7±12 (SVC2) ±
O7±5 (SVC3)Always1 MW or higher
O7±12 (SVC2) ±
O7±6 (SVC4)Always1 MW or higher
O7±11 (SVC1) ±
O7±5 (SVC3)Always1 MW or higher
NG Repair or replace seat wire No. 1.
OK
6 Check seat wire No. 1 (short to ground).
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
Tester ConnectionConditionSpecified Condition
O7±5 (SVC3) ±
Body groundAlways1 MW or higher
O7±6 (SVC4) ±
Body groundAlways1 MW or higher
O7±11 (SVC1) ±
Body groundAlways1 MW or higher
O7±12 (SVC2) ±
Body groundAlways1 MW or higher
NG Repair or replace seat wire No. 1.
OK

DI±1338
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1532 Author: Date:
2005 SEQUOIA (RM1146U)
7 Check DTC.
PREPARATION:
(a) Connect the connectors to the occupant classification ECU and the 4 occupant classification sensors.
(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 B1793 is not output.
HINT:
Codes other than DTC B1793 may be output at this time, but they are not related to this check.
NG Go to step 8.
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).