DTC B1810-53: Short in Driver Side Squib 2nd Step Circuit; DTC B1811-53: Open in Driver Side Squib 2nd Step Circuit; DTC B1812-53: Short to GND in Driver Side Squib 2nd Step Circuit; DTC B1813-53: Short to B+ in Driver Side Squib 2nd Step Circuit [10/2014 - 05/2019]: Procedure

CHECK HORN BUTTON ASSEMBLY (DRIVER SIDE SQUIB 2ND STEP)

Turn the power switch off.

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

*1	Horn Button Assembly (Driver Side Squib 2nd Step)
*2	Spiral with Sensor Cable Sub-assembly
*3	Airbag ECU Assembly
*4	Connector E
*5	SST
*a	Front view of wire harness connector (to Horn Button Assembly [Driver Side Squib 2nd Step])
*b	Color: Black

Disconnect the cable from the negative (-) auxiliary battery terminal, and wait for at least 90 seconds.
Disconnect the connector from the horn button assembly.
Connect the white wire side of SST (resistance: 2.1 Ω) to connector E (black connector).
WARNING:
Never connect the tester to the horn button assembly (driver side squib 2nd step) for measurement, as this may lead to a serious injury due to airbag deployment.
NOTE:
- Do not forcibly insert SST into the terminals of the connector when connecting SST.
- Insert SST straight into the terminals of the connector.
- SST: 09843-18061
Connect the cable to the negative (-) auxiliary battery terminal, and wait for at least 2 seconds.
Turn the power switch on (IG), and wait for at least 60 seconds.
Clear the DTCs.
Refer to DTC CHECK / CLEAR [10/2014 - 05/2019]

Body Electrical > SRS Airbag > Clear DTCs
Turn the power switch off.
Turn the power switch on (IG), and wait for at least 60 seconds.

Check for DTCs.

Refer to DTC CHECK / CLEAR [10/2014 - 05/2019]

Body Electrical > SRS Airbag > Trouble Codes

Result

Proceed to
DTC B1810/53, B1811/53, B1812/53 or B1813/53 is not output
DTC B1810/53, B1811/53, B1812/53 or B1813/53 is output

HINT:

Codes other than DTC B1810/53, B1811/53, B1812/53 and B1813/53 may be output at this time, but they are not related to this check.

Turn the power switch off.
Disconnect the cable from the negative (-) auxiliary battery terminal, and wait for at least 90 seconds.
Disconnect SST from connector E.

Result:

DTC B1810/53, B1811/53, B1812/53 or B1813/53 is not output

REPLACE HORN BUTTON ASSEMBLY. Refer to REMOVAL [10/2014 - 05/2019]

Result:

DTC B1810/53, B1811/53, B1812/53 or B1813/53 is output

See step 2

CHECK CONNECTORS

Disconnect the connectors from the airbag ECU assembly.

Check that the connectors (on the airbag ECU assembly side and horn button assembly side) are not damaged.

The lock button is not disengaged, and the claw of the lock is not deformed or damaged.

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

*1	Horn Button Assembly (Driver Side Squib 2nd Step)
*2	Spiral with Sensor Cable Sub-assembly
*3	Airbag ECU Assembly
*4	Instrument Panel Wire

Result

Proceed to
OK
NG

Result:

REPLACE INSTRUMENT PANEL WIRE OR SPIRAL WITH SENSOR CABLE SUB-ASSEMBLY

Result:

See step 3

CHECK DRIVER SIDE SQUIB 2ND STEP CIRCUIT

Connect the cable to the negative (-) auxiliary battery terminal, and wait for at least 2 seconds.

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

*1	Horn Button Assembly (Driver Side Squib 2nd Step)
*2	Spiral with Sensor Cable Sub-assembly
*3	Airbag ECU Assembly
*4	Connector E
*a	Front view of wire harness connector (to Horn Button Assembly [Driver Side Squib 2nd Step])
*b	Color: Black

Turn the power switch on (IG).

Measure the voltage according to the value(s) in the table below.

Standard Voltage

Tester Connection	Switch Condition	Specified Condition
z5-2 (D2+) - Body ground	Power switch on (IG)	Below 1 V
z5-1 (D2-) - Body ground	Power switch on (IG)	Below 1 V

Turn the power switch off.
Disconnect the cable from the negative (-) auxiliary battery terminal, and wait for at least 90 seconds.

Measure the resistance according to the value(s) in the table below.

Standard Resistance

Tester Connection	Condition	Specified Condition
z5-2 (D2+) - z5-1 (D2-)	Always	Below 1 Ω

Release the activation prevention mechanism built into connector B.
Refer to DIAGNOSIS SYSTEM [10/2014 - ]

Measure the resistance according to the value(s) in the table below.

Standard Resistance

Tester Connection	Condition	Specified Condition
z5-2 (D2+) - z5-1 (D2-)	Always	1 MΩ or higher

Restore the released activation prevention mechanism of connector B to its original condition.

Measure the resistance according to the value(s) in the table below.

Standard Resistance

Tester Connection	Condition	Specified Condition
z5-2 (D2+) - Body ground	Always	1 MΩ or higher
z5-1 (D2-) - Body ground	Always	1 MΩ or higher

Result

Proceed to
OK
NG

Result:

See step 5

Result:

See step 4

CHECK DTC

Connect the connectors to the horn button assembly and airbag ECU assembly.

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

*1	Horn Button Assembly (Driver Side Squib 2nd Step)
*2	Spiral with Sensor Cable Sub-assembly
*3	Airbag ECU Assembly

Connect the cable to the negative (-) auxiliary battery terminal, and wait for at least 2 seconds.
Turn the power switch on (IG), and wait for at least 60 seconds.
Clear the DTCs.
Refer to DTC CHECK / CLEAR [10/2014 - 05/2019]

Body Electrical > SRS Airbag > Clear DTCs
Turn the power switch off.
Turn the power switch on (IG), and wait for at least 60 seconds.

Check for DTCs.

Refer to DTC CHECK / CLEAR [10/2014 - 05/2019]

Body Electrical > SRS Airbag > Trouble Codes

Result

Proceed to
DTC B1810/53, B1811/53, B1812/53 or B1813/53 is not output
DTC B1810/53, B1811/53, B1812/53 or B1813/53 is output

HINT:

Codes other than DTC B1810/53, B1811/53, B1812/53 and B1813/53 may be output at this time, but they are not related to this check.

Result:

DTC B1810/53, B1811/53, B1812/53 or B1813/53 is not output

USE SIMULATION METHOD TO CHECK. Refer to DIAGNOSIS SYSTEM [10/2014 - ]

Result:

DTC B1810/53, B1811/53, B1812/53 or B1813/53 is output

REPLACE AIRBAG ECU ASSEMBLY. Refer to REMOVAL [10/2014 - 05/2019]

CHECK INSTRUMENT PANEL WIRE

Disconnect the instrument panel wire connector from the spiral with sensor cable sub-assembly.

*1	Instrument Panel Wire
*2	Spiral with Sensor Cable Sub-assembly
*3	Airbag ECU Assembly
*4	Connector C
*a	Rear view of wire harness connector (to Spiral with Sensor Cable Sub-assembly)

Connect the cable to the negative (-) auxiliary battery terminal, and wait for at least 2 seconds.
Turn the power switch on (IG).

Measure the voltage according to the value(s) in the table below.

Standard Voltage

Tester Connection	Switch Condition	Specified Condition
I5-4 (D2+) - Body ground	Power switch on (IG)	Below 1 V
I5-3 (D2-) - Body ground	Power switch on (IG)	Below 1 V

Turn the power switch off.
Disconnect the cable from the negative (-) auxiliary battery terminal, and wait for at least 90 seconds.

Measure the resistance according to the value(s) in the table below.

Standard Resistance

Tester Connection	Condition	Specified Condition
I5-4 (D2+) - I5-3 (D2-)	Always	Below 1 Ω

Release the activation prevention mechanism built into connector B.
Refer to DIAGNOSIS SYSTEM [10/2014 - ]

Measure the resistance according to the value(s) in the table below.

Standard Resistance

Tester Connection	Condition	Specified Condition
I5-4 (D2+) - I5-3 (D2-)	Always	1 MΩ or higher

Restore the released activation prevention mechanism of connector B to its original condition.

Measure the resistance according to the value(s) in the table below.

Standard Resistance

Tester Connection	Condition	Specified Condition
I5-4 (D2+) - Body ground	Always	1 MΩ or higher
I5-3 (D2-) - Body ground	Always	1 MΩ or higher

Result

Proceed to
OK
NG

Result:

REPLACE SPIRAL WITH SENSOR CABLE SUB-ASSEMBLY. Refer to REMOVAL [10/2014 - 09/2017] , or refer to REMOVAL [09/2017 - 05/2019]

Result:

REPLACE INSTRUMENT PANEL WIRE