2001 TOYOTA SEQUOIA ECU

C84211H24024H24005
Occupant
Classification
ECU
Airbag
Sensor
Assembly
A
FSR+
FSR± B C D E F
BL1Seat Wire No. 1
Floor Wire
DI±1212
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1406 Author: Date:
2005 SEQUOIA (RM1146U)
12 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.

H01010G27652H24025H24542
Seat
Position
Airbag
Sensor
Assembly
LSP±LSP+
Airbag
Sensor
Assembly
Service WireA19
A
B C D
B18
Floor Wire No. 2
3
5
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±1215
1409 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 airbag sensor assembly and the seat position air-
bag sensor assembly.
OK:
The connectors are connected securely.
NG Connect connectors, then go to step 1.
OK
3 Check floor wire No. 2 (open).
PREPARATION:
(a) Disconnect the connectors from the airbag sensor as-
sembly and the seat position airbag sensor assembly.
(b) Using a service wire, connect B18±3 and B18±5 of con-
nector ºCº.
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
A19±9 (LSP+) ±
A19±17 (LSP±)AlwaysBelow 1 W
NG Repair or replace floor wire No. 2.
OK

H03353G27651H24026H24551
Airbag
Sensor
Assembly
LBE+
LBE± Front Seat
Inner Belt LH
B C D
A
Service Wire
Floor Wire No. 2
A19
B18
4
6
DI±1222
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1416 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 airbag sensor assembly and the front seat inner
belt LH.
OK:
The connectors are connected securely.
NG Connect connectors, then go to step 1.
OK
3 Check floor wire No. 2 (open).
PREPARATION:
(a) Disconnect the connectors from the airbag sensor as-
sembly and the front seat inner belt LH.
(b) Using a service wire, connect B18±4 and B18±6 of con-
nector ºCº.
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
A19±10 (LBE+) ±
A19±18 (LBE±)AlwaysBelow 1 W
NG Repair or replace floor wire No. 2.
OK

DI±1244
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1438 Author: Date:
2005 SEQUOIA (RM1146U)
7 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 airbag sensor assembly and the combination meter.
OK:
The connectors are connected securely.
NG Connect connector, then go to step 1.
OK
8 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

± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±1249
1443 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Check battery.
CHECK:
Measure the voltage of the battery.
OK:
Voltage: 11 to 14 V
NG Replace battery.
OK
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 airbag sensor assembly and combination meter.
OK:
The connectors are connected securely.
NG Connect connectors, then go to step 1.
OK
3 Check combination meter.
PREPARATION:
(a) Disconnect the connectors from the airbag sensor assembly.
(b) Connect the negative (±) terminal cable to the battery, and wait for at least 2 seconds.
CHECK:
Turn the ignition switch to the ON position, check the operation of the SRS warning light.
OK:
The SRS warning light comes on (goes off 6 seconds after the ignition switch is turned to the
ON position).
NG Go to combination meter system
(see page DI±1610).
OK

± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±1251
1445 Author: Date:
2005 SEQUOIA (RM1146U)
DTC B1771 Passenger Side Buckle Switch Circuit
Malfunction
CIRCUIT DESCRIPTION
The passenger side buckle switch circuit consists of the occupant classification ECU and the front seat inner
belt RH.
DTC B1771 is recorded when a malfunction is detected in the passenger side buckle switch circuit.
Troubleshoot DTC B1771 first when the DTC B1771 and B1795 are output simultaneously.
DTC No.DTC Detecting ConditionTrouble Area
B1771

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 passen-
ger side buckle switch circuit for 2 seconds.

Passenger side buckle switch malfunction

Occupant classification ECU malfunction

Front seat inner belt RH

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 B1771 is output, perform troubleshooting
for the DTC.
DIDH4±01

H23244
Occupant Classification ECU
O6
O6 R B17
Buckle SW RH
L
129
5BSW
BGND DI±1252
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1446 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM

± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±1253
1447 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 B1771 is not output.
HINT:
Codes other than DTC B1771 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).