05–558

DIAGNOSTICS – SUPPLEMENTAL RESTRAINT SYSTEM (April, 2003) 055ZM–04

DTC B1181/18 OPEN IN D SQUIB (2ND STEP) CIRCUIT

CIRCUIT DESCRIPTION
The D squib circuit consists of the airbag sensor assy center, spiral cable sub–assy and horn button assy.
It causes the SRS to deploy when the SRS deployment conditions are satisfied.
DTC B1181/18 is recorded when an open is detected in the D squib circuit (2nd step).
DTC No. DTC Detecting Condition Trouble Area

Open circuit in D+ wire harness or D– wire harness of squib
Horn button assy (D squib, 2nd step)

D squib (2nd step) malfunction
Spiral cable sub–assy
B1181/18

Spiral cable sub–assy malfunction
Airbag sensor assy center

Airbag sensor assy center malfunction
Instrument panel wire

WIRING DIAGRAM
See page 05–554.
INSPECTION PROCEDURE
1 CHECK D SQUIB CIRCUIT(AIRBAG SENSOR ASSY CENTER – HORN BUTTON
ASSY)

(a) Disconnect the negative (–) terminal cable from the bat-
tery, and wait at least for 90 seconds.
D Squib Airbag
(b) Disconnect the connectors between the horn button assy
Spiral and the airbag sensor assy center.
Sensor
Cable
Assy (c) For the black connector (on the spiral cable sub–assy
Sub–Assy
Center side) between the horn button assy and the spiral cable
sub–assy, measure the resistance between D2+ and
D2–.
OK:
Resistance: Below 1 Ω

Color: Black
H01001
C89244 H41475

NG Go to step 4

OK

2004 COROLLA (RM1037U)

Author: Date: 723

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DIAGNOSTICS – SUPPLEMENTAL RESTRAINT SYSTEM (April, 2003)

2 CHECK AIR BAG SENSOR ASSY CENTER

SST 09843–18040
(a) Connect the connector to the airbag sensor assy center.
(b) Using a service wire, connect D2+ and D2– of the black
D Squib Airbag connector (on the spiral cable sub–assy side) between
Spiral
Sensor
Cable the horn button assy and the spiral cable sub–assy.
Sub–Assy Assy
(c) Connect the negative (–) terminal cable to the battery,
Center
and wait at least for 2 seconds.
(d) Turn the ignition switch to ON, and wait at least for 20 se-
conds.
(e) Clear the DTC stored in memory (See page 05–424).
(f) Turn the ignition switch to LOCK, and wait at least for 20
seconds.
Color: Black (g) Turn the ignition switch to ON, and wait at least for 20 se-
conds.
DTC B1181/18 (h) Check the DTC (See page 05–424).
DLC3
OK:
DTC B1181/18 is not output.
HINT:
CG Tc Codes other than code B1181/18 may be output at this time, but
H01002
C89252
H10600 C89253 H42139 they are not relevant to this check.
NG REPLACE AIR BAG SENSOR ASSY CENTER

OK

2004 COROLLA (RM1037U)

Author: Date: 724

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DIAGNOSTICS – SUPPLEMENTAL RESTRAINT SYSTEM (April, 2003)

3 CHECK D SQUIB

SST 09843–18040
(a) Turn the ignition switch to LOCK.
(b) Disconnect the negative (–) terminal cable from the bat-
D Squib Airbag tery, and wait at least for 90 seconds.
Spiral
Sensor
Cable (c) Connect the horn button assy connectors.
Assy
Sub–Assy (d) Connect the negative (–) terminal cable to the battery,
Center
and wait at least for 2 seconds.
(e) Turn the ignition switch to ON, and wait at least for 20 se-
conds.
DLC3 DTC B1181/18
(f) Clear the DTC stored in memory (See page 05–424).
(g) Turn the ignition switch to LOCK, and wait at least for 20
seconds.
(h) Turn the ignition switch to ON, and wait at least for 20 se-
CG Tc conds.
H01003
H10600 C89253 H42140 (i) Check the DTC (See page 05–424).
OK:
DTC B1181/18 is not output.
HINT:
Codes other than code B1181/18 may be output at this time, but
they are not relevant to this check.
NG REPLACE HORN BUTTON ASSY

OK

USE SIMULATION METHOD TO CHECK

4 CHECK INSTRUMENT PANEL WIRE(AIRBAG SENSOR ASSY CENTER – SPIRAL

CABLE SUB–ASSY)

(a) Disconnect the connector of the instrument panel wire.

D Squib Airbag (b) For the connector (on the spiral cable sub–assy side) be-
Spiral
Cable Sensor tween the airbag sensor assy center and the spiral cable
Sub–Assy Assy sub–assy, measure the resistance between D2+ and
Center D2–.
OK:
Resistance: Below 1 Ω

NG REPAIR OR REPLACE INSTRUMENT PANEL

WIRE(AIRBAG SENSOR ASSY CENTER – SPI-
H01004
RAL CABLE SUB–ASSY)
H41424 H41478

OK

2004 COROLLA (RM1037U)

Author: Date: 725

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DIAGNOSTICS – SUPPLEMENTAL RESTRAINT SYSTEM (April, 2003)

5 CHECK SPIRAL CABLE SUB–ASSY

(a) For the black connector (on the spiral cable sub–assy
side) between the horn button assy and the spiral cable
sub–assy, measure the resistance between D2+ and
D Squib Airbag
Spiral D2–.
Sensor
Cable OK:
Sub–Assy Assy
Center Resistance: Below 1 Ω

Color: Black
H01000
C89244 H41479

NG REPLACE SPIRAL CABLE SUB–ASSY

OK

USE SIMULATION METHOD TO CHECK

2004 COROLLA (RM1037U)

Author: Date: 726