Page 1536 of 4323
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).
Page 1537 of 4323
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
Page 1538 of 4323
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
Page 1539 of 4323
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
Page 1540 of 4323
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).
Page 1541 of 4323
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±1339
1533 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).
HINT:
Perform the inspection using parts from a normal vehicle if possible.
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.
NG Go to step 12.
OK
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)
NG Go to step 12.
OK
Page 1542 of 4323
DI±1340
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1534 Author: Date:
2005 SEQUOIA (RM1146U)
11 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 12.
OK
END
Page 1544 of 4323
DI±1342
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1536 Author: Date:
2005 SEQUOIA (RM1146U)
DTC B1794 Occupant Classification ECU Battery
Positive Line Open
CIRCUIT DESCRIPTION
This circuit consists of the occupant classification ECU and the power source circuit (battery, fuse, wire har-
ness).
DTC B1794 is recorded when a malfunction is detected in the occupant classification ECU or the power
source circuit.
HINT:
When DTC B1794 is output after switching the ignition switch LOCK±ON±LOCK 50 times in a row when a
malfunction occurs in the power source circuit for the occupant classification system, the DTC is output again
when a malfunction is detected even once after being cleared, unless the normal system code is input.
DTC No.DTC Detecting ConditionTrouble Area
B1794
The ignition switch is turned from LOCK to ON, hold for 10
seconds or more, and back to LOCK again 50 times in a
row when a malfunction occurs in the power source circuit
for the occupant classification system.
Occupant classification ECU malfunctionBattery
ECU±B Fuse
Floor wire
Seat wire No. 1
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 B1794 is output, perform troubleshooting
for the DTC.
DIDHF±01
