Page 1553 of 4323
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±1351
1545 Author: Date:
2005 SEQUOIA (RM1146U)
2 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
3 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
4 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 1554 of 4323

DI±1352
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1546 Author: Date:
2005 SEQUOIA (RM1146U)
DTC B1800/51 Short in D Squib Circuit
DTC B1801/51 Open in D Squib Circuit
DTC B1802/51 Short in D Squib Circuit (to Ground)
DTC B1803/51 Short in D Squib Circuit (to B+)
CIRCUIT DESCRIPTION
The D squib circuit consists of the airbag sensor assembly, the spiral cable and the steering wheel pad.
The circuit instructs the SRS to deploy when deployment conditions are met.
These DTCs are recorded when a malfunction is detected in the D squib circuit.
DTC No.DTC Detection ConditionTrouble Area
B1800/51
The airbag sensor assembly receives a line short circuit
signal 5 times in the D squib circuit during primary check.
Spiral cable malfunction
D squib malfunction
Airbag sensor assembly malfunctionSteering wheel pad (D squib)
Airbag sensor assembly
Spiral cable
Cowl wire
B1801/51
The airbag sensor assembly receives an open circuit sig-
nal in the D squib circuit for 2 seconds.
Spiral cable malfunction
D squib malfunction
Airbag sensor assembly malfunctionSteering wheel pad (D squib)
Airbag sensor assembly
Spiral cable
Cowl wire
B1802/51
The airbag sensor assembly receives a short circuit to
ground signal in the D squib circuit for 0.5 seconds.
Spiral cable malfunction
D squib malfunction
Airbag sensor assembly malfunctionSteering wheel pad (D squib)
Airbag sensor assembly
Spiral cable
Cowl wire
B1803/51
The airbag sensor assembly receive a short to B+ circuit
signal in the D squib circuit for 0.5 seconds.
Spiral cable malfunction
D squib malfunction
Airbag sensor assembly malfunctionSteering wheel pad (D squib)
Airbag sensor assembly
Spiral cable
Cowl wire
DIDHI±01
Page 1555 of 4323
H01451
Airbag Sensor Assembly
A205
D+ Y±B D Squib
A23
Spiral CableA206
D± Y 1
2
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±1353
1547 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM
Page 1556 of 4323

DI±1354
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1548 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
CAUTION:
Be sure to perform the following procedures before troubleshooting to avoid unexpected airbag de-
ployment.
(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) Disconnect the connectors from the airbag sensor assembly.
(d) Disconnect the connectors from the steering wheel pad.
(e) Disconnect the connectors from the front passenger airbag assembly.
(f) w/ Side and curtain shield airbag:
Disconnect the connectors from the side airbag assembly LH and RH.
(g) w/ Side and curtain shield airbag:
Disconnect the connectors from the curtain shield airbag assembly LH and RH.
(h) Disconnect the connectors from the front seat outer belt LH and RH.
1 Check DTC.
CHECK:
Proceed to each step according to how to read DTC.
(1) If using the hand±held tester (read the 5±digit of DTC):
Using the hand±held tester, check the DTCs (see page DI±1147).
RESULT:
DTC B1800 is output.A
DTC B1801 is output.B
DTC B1802 is output.C
DTC B1803 is output.D
(2) If not using the hand±held tester (read the 2±digit of DTC):
Check the DTCs (see page DI±1147).
RESULT:
DTC 51 is output.E
HINT:
Codes other than DTC B1800, B1801, B1802, B1803 and DTC 51 may be output at this time, but they are
not related to this check.
B Go to step 4.
C Go to step 5.
D Go to step 6.
E Go to step 7.
A
Page 1557 of 4323
H23795H23974
H01001H23987
D+
D±
Color: Orange
D Squib
Spiral
CableA
B C D E FAirbag
Sensor
Assembly
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±1355
1549 Author: Date:
2005 SEQUOIA (RM1146U)
2 Check connector.
CHECK:
Check that the spiral cable connectors (on the steering wheel pad side) are not damaged.
OK:
The lock button is not disengaged, or the claw of the lock is not deformed or damaged.
NG Replace spiral cable (see page RS±21).
OK
3 Check D squib circuit (short).
PREPARATION:
Release the activation prevention mechanism built into con-
nector ºBº (see page DI±1137).
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
Tester ConnectionConditionSpecified Condition
D+ ± D±Always1 MW or higher
NG Go to step 13.
OK
Go to step 10.
Page 1558 of 4323
H23795H23974
H01001H23987
D+
D±
Color: Orange
D Squib
Spiral
CableA
B C D E FAirbag
Sensor
Assembly
H23795H23974
H01001H23987
D+
D±
Color: Orange
D Squib
Spiral
CableA
B C D E FAirbag
Sensor
Assembly
DI±1356
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1550 Author: Date:
2005 SEQUOIA (RM1146U)
4 Check D squib circuit (open).
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
Tester ConnectionConditionSpecified Condition
D+ ± D±AlwaysBelow 1 W
NG Go to step 15.
OK
Go to step 11.
5 Check D squib circuit (short to ground).
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
Tester ConnectionConditionSpecified Condition
D+ ± Body groundAlways1 MW or higher
D± ± Body groundAlways1 MW or higher
NG Go to step 17.
OK
Go to step 11.
Page 1559 of 4323
H23795H23974
H01001H23987
D+
D±
Color: Orange
D Squib
Spiral
CableA
B C D E FAirbag
Sensor
Assembly
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±1357
1551 Author: Date:
2005 SEQUOIA (RM1146U)
6 Check D squib (short to B+).
PREPARATION:
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
D+ ± Body groundIgnition switch ONBelow 1 V
D± ± Body groundIgnition switch ONBelow 1 V
NG Go to step 19.
OK
Go to step 11.
7 Check connector.
CHECK:
Check that the spiral cable connectors (on the steering wheel pad side) are not damaged.
OK:
The lock button is not disengaged, or the claw of the lock is not deformed or damaged.
NG Replace spiral cable (see page RS±21).
OK
Page 1560 of 4323

H23795H23974
H01001H23987
D+
D±
Color: Orange
D Squib
Spiral
CableA
B C D E FAirbag
Sensor
Assembly
DI±1358
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1552 Author: Date:
2005 SEQUOIA (RM1146U)
8 Check D squib circuit.
PREPARATION:
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
D+ ± Body groundIgnition switch ONBelow 1 V
D± ± Body groundIgnition switch ONBelow 1 V
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
D+ ± D±AlwaysBelow 1 W
D+ ± Body groundAlways1 MW or higher
D± ± Body groundAlways1 MW or higher
PREPARATION:
Release the activation prevention mechanism built into the con-
nector ºBº (see page DI±1137).
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
Tester ConnectionConditionSpecified Condition
D+ ± D±Always1 MW or higher
NG Go to step 21.
OK