TOYOTA SEQUOIA 2001 Service Repair Manual

± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±1299
1493 Author: Date:
2005 SEQUOIA (RM1146U)
12 Replace front seat assembly RH.
(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 front seat assembly RH (see page BO±112, BO±126).
NEXT
13 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
14 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

DI±1300
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1494 Author: Date:
2005 SEQUOIA (RM1146U)
DTC B1785 Occupant Classification Sensor Front LH
Collision Detection
CIRCUIT DESCRIPTION
DTC B1785 is output when the occupant classification ECU receives a collision detection signal sent by the
occupant classification sensor front LH if an accident occurs.
DTC B1785 is also output when the front seat assembly RH is subjected to a strong impact, even if an actual
accident does not occur.
However, when the occupant classification ECU outputs a collision detection signal, even if the vehicle is
not in a collision, DTC B1785 can be cleared by ºZero point calibrationº and ºSensitivity checkº.
Therefore, if DTC B1785 is output, first perform ºZero point calibrationº and ºSensitivity checkº.
DTC No.DTC Detecting ConditionTrouble Area
B1785

Front seat assembly RH malfunction

Occupant classification ECU malfunction

Occupant classification sensor front LH detects heavy
load.
Front seat assembly RH
(Occupant classification sensor front LH)

Occupant classification ECU
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 B1785 is output, perform troubleshooting
for the DTC.
WIRING DIAGRAM
See page DI±1260.
INSPECTION PROCEDURE
1 Perform zero point calibration.
(a) Connect the hand±held tester to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Using the hand±held tester, perform ºZero point calibrationº (see page DI±1128).
OK:
The ºCOMPLETEDº is displayed.
NG Go to step 4.
OK
DIDH9±01

± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±1301
1495 Author: Date:
2005 SEQUOIA (RM1146U)
2 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)
NG Go to step 4.
OK
3 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 B1785 is not output.
HINT:
Codes other than DTC B1785 may be output at this time, but they are not related to this check.
NG Go to step 4.
OK
END

DI±1302
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1496 Author: Date:
2005 SEQUOIA (RM1146U)
4 Replace front seat assembly RH.
(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 front seat assembly RH (see page BO±112, BO±126).
HINT:
Perform the inspection using parts from a normal vehicle if possible.
NEXT
5 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.
NG Go to step 8.
OK
6 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)
NG Go to step 8.
OK

± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±1303
1497 Author: Date:
2005 SEQUOIA (RM1146U)
7 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 B1785 is not output.
HINT:
Codes other than DTC B1785 may be output at this time, but they are not related to this check.
NG Go to step 8.
OK
END

DI±1304
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1498 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

± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±1305
1499 Author: Date:
2005 SEQUOIA (RM1146U)
DTC B1786 Occupant Classification Sensor Front RH
Collision Detection
CIRCUIT DESCRIPTION
DTC B1786 is output when the occupant classification ECU receives a collision detection signal sent by the
occupant classification sensor front RH if an accident occurs.
DTC B1786 is also output when the front seat assembly RH is subjected to a strong impact, even if an actual
accident does not occur.
However, when the occupant classification ECU outputs a collision detection signal, even if the vehicle is
not in a collision, DTC B1786 can be cleared by ºZero point calibrationº and ºSensitivity checkº.
Therefore, if DTC B1786 is output, first perform ºZero point calibrationº and ºSensitivity checkº.
DTC No.DTC Detecting ConditionTrouble Area
B1786

Front seat assembly RH malfunction

Occupant classification ECU malfunction

Occupant classification sensor front RH detects heavy
load.
Front seat assembly RH
(Occupant classification sensor front RH)

Occupant classification ECU
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 B1786 is output, perform troubleshooting
for the DTC.
WIRING DIAGRAM
See page DI±1270.
INSPECTION PROCEDURE
1 Perform zero point calibration.
(a) Connect the hand±held tester to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Using the hand±held tester, perform ºZero point calibrationº (see page DI±1128).
OK:
The ºCOMPLETEDº is displayed.
NG Go to step 4.
OK
DIDHA±01

DI±1306
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1500 Author: Date:
2005 SEQUOIA (RM1146U)
2 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)
NG Go to step 4.
OK
3 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 B1786 is not output.
HINT:
Codes other than DTC B1786 may be output at this time, but they are not related to this check.
NG Go to step 4.
OK
END

± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±1307
1501 Author: Date:
2005 SEQUOIA (RM1146U)
4 Replace front seat assembly RH.
(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 front seat assembly RH (see page BO±112, BO±126).
HINT:
Perform the inspection using parts from a normal vehicle if possible.
NEXT
5 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.
NG Go to step 8.
OK
6 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)
NG Go to step 8.
OK

DI±1308
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1502 Author: Date:
2005 SEQUOIA (RM1146U)
7 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 B1786 is not output.
HINT:
Codes other than DTC B1786 may be output at this time, but they are not related to this check.
NG Go to step 8.
OK
END