Toyota Tacoma (2015-2018) Service Manual: Short in Driver Side Squib 2nd Step Circuit (B1810/53-B1813/53)

Toyota Tacoma (2015-2018) Service Manual / Supplemental Restraint Systems / Airbag System / Short in Driver Side Squib 2nd Step Circuit (B1810/53-B1813/53)

DESCRIPTION

The driver side squib 2nd step circuit consists of the airbag sensor assembly, the spiral cable with sensor sub-assembly and the horn button assembly.

The circuit signals the SRS to deploy when airbag deployment conditions are met.

These DTCs are set when a malfunction is detected in the driver side squib 2nd step circuit.

DTC No.	DTC Detecting Conditions	Trouble Areas
B1810/53	The airbag sensor assembly receives a line short circuit signal in the driver side squib 2nd step circuit for 2 seconds Driver side squib 2nd step malfunction Spiral cable with sensor sub-assembly malfunction Airbag sensor assembly malfunction	Instrument panel wire Spiral cable with sensor sub-assembly Horn button assembly (Driver side squib 2nd step) Airbag sensor assembly
B1811/53	The airbag sensor assembly receives an open circuit signal in the driver side squib 2nd step circuit for 2 seconds malfunction Driver side squib 2nd step Spiral cable with sensor sub-assembly malfunction Airbag sensor assembly malfunction	Instrument panel wire Spiral cable with sensor sub-assembly Horn button assembly (Driver side squib 2nd step) Airbag sensor assembly
B1812/53	The airbag sensor assembly receives a short circuit to ground signal in the driver side squib 2nd step circuit for 0.5 seconds Driver side squib 2nd step malfunction Spiral cable with sensor sub-assembly malfunction Airbag sensor assembly malfunction	Instrument panel wire Spiral cable with sensor sub-assembly Horn button assembly (Driver side squib 2nd step) Airbag sensor assembly
B1813/53	The airbag sensor assembly receives a short circuit to B+ signal in the driver side squib 2nd step circuit for 0.5 seconds Driver side squib 2nd step malfunction Spiral cable with sensor sub-assembly malfunction Airbag sensor assembly malfunction	Instrument panel wire Spiral cable with sensor sub-assembly Horn button assembly (Driver side squib 2nd step) Airbag sensor assembly

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

After turning the ignition switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work (See page ).

HINT:

Perform the simulation method by selecting check mode (Signal Check) using the Techstream (See page ).
After selecting check mode (Signal Check), perform the simulation method by wiggling each connector of the airbag system or driving the vehicle on a city road or rough road (See page ).

PROCEDURE

CHECK DTC

(a) Proceed to the appropriate step according to DTC readings.

(1) If using the Techstream (read the 5-digit DTCs): Using the Techstream, check for DTCs (See page Result ).

Result

Result	Proceed to
DTC B1810 is output.	A
DTC B1811 is output.	B
DTC B1812 is output.	C
DTC B1813 is output.	D

GO TO STEP 7

GO TO STEP 11

GO TO STEP 15

2.	CHECK CONNECTOR

(a) Turn the ignition switch off.

(b) Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.

OK:

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

REPLACE SPIRAL CABLE WITH SENSOR SUB-ASSEMBLY

3.	CHECK CONNECTION OF CONNECTORS

(a) Check that the connectors are properly connected to the airbag sensor assembly and the spiral cable with sensor sub-assembly.

OK:

The connectors are properly connected.

CONNECT CONNECTORS

4.	CHECK SPIRAL CABLE WITH SENSOR SUB-ASSEMBLY (FOR SHORT)

(a) Disconnect the spiral cable with sensor sub-assembly connectors from the instrument panel wire and steering pad horn button assembly.

(b) Release the activation prevention mechanism built into connector D (See page (c) Measure the resistance according to the value(s) in the table below. ).

Standard Resistance:

Tester Connection	Condition	Specified Condition
D2+ - D2-	Always	1 MΩ or Higher

Text in Illustration

*1	Driver Side Squib 2nd Step
*2	Spiral Cable with Sensor Sub-assembly
*3	Airbag Sensor Assembly
*a	Color: Black

REPLACE SPIRAL CABLE WITH SENSOR SUB-ASSEMBLY

5.	CHECK INSTRUMENT PANEL WIRE (FOR SHORT)

(a) Disconnect the instrument panel wire connector from the airbag sensor assembly.

(b) Release the activation prevention mechanism built into connector B (See page (c) Measure the resistance according to the value(s) in the table below. ).

Standard Resistance:

Tester Connection	Condition	Specified Condition
A26-4 (D2+) - A26-3 (D2-)	Always	1 MΩ or Higher

Text in Illustration

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

REPLACE INSTRUMENT PANEL WIRE

6.	CHECK AIRBAG SENSOR ASSEMBLY

(a) Connect the instrument panel wire connectors to the airbag sensor assembly and spiral cable with sensor sub-assembly.

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

(d) Clear any DTCs stored in the memory (See page (e) Turn the ignition switch off. ).

(e) Turn the ignition switch off.

(f) Turn the ignition switch to ON, and wait for at least 60 seconds.

(g) Check for DTCs (See page OK: ).

OK:

DTC B1810 is not output.

Text in Illustration

*1	Driver Side Squib 2nd Step
*2	Spiral Cable with Sensor Sub-assembly
*3	Airbag Sensor Assembly

HINT:

DTCs other than B1810 may be output at this time, but they are not related to this check.

Result

Result	Proceed to
NG	A
OK	B

REPLACE AIRBAG SENSOR ASSEMBLY

GO TO STEP 20

7.	CHECK CONNECTOR

(a) Turn the ignition switch off.

(b) Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.

OK:

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

REPLACE SPIRAL CABLE WITH SENSOR SUB-ASSEMBLY

8.	CHECK CONNECTION OF CONNECTORS

(a) Check that the spiral cable with sensor sub-assembly connectors (on the horn button assembly side) are properly connected.

OK:

The connectors are properly connected.

CONNECT CONNECTORS

9.	CHECK SPIRAL CABLE WITH SENSOR SUB-ASSEMBLY (FOR OPEN)

(a) Disconnect the spiral cable with sensor sub-assembly connectors from the instrument panel wire and horn button assembly.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
D2+ - D2-	Always	Below 1 Ω

Text in Illustration

*1	Driver Side Squib 2nd Step
*2	Spiral Cable with Sensor Sub-assembly
*3	Airbag Sensor Assembly
*a	Color: Black

REPLACE SPIRAL CABLE WITH SENSOR SUB-ASSEMBLY

10.	CHECK INSTRUMENT PANEL WIRE (FOR OPEN)

(a) Disconnect the instrument panel wire connector from the airbag sensor assembly.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A26-4 (D2+) - A26-3 (D2-)	Always	Below 1 Ω

Text in Illustration

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

Result

Result	Proceed to
NG	A
OK	B

REPLACE INSTRUMENT PANEL WIRE

GO TO STEP 19

11.	CHECK CONNECTOR

(a) Turn the ignition switch off.

(b) Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.

OK:

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

REPLACE SPIRAL CABLE WITH SENSOR SUB-ASSEMBLY

12.	CHECK CONNECTION OF CONNECTORS

(a) Check that the spiral cable with sensor sub-assembly connectors (on the horn button assembly side) are properly connected.

OK:

The connectors are properly connected.

CONNECT CONNECTORS

13.	CHECK SPIRAL CABLE WITH SENSOR SUB-ASSEMBLY (TO GROUND)

(a) Disconnect the spiral cable with sensor sub-assembly connector from the instrument panel wire and horn button assembly.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
D2+ - Body ground	Always	1 MΩ or Higher
D2- - Body ground	Always	1 MΩ or Higher

Text in Illustration

*1	Driver Side Squib 2nd Step
*2	Spiral Cable with Sensor Sub-assembly
*3	Airbag Sensor Assembly
*a	Color: Black

REPLACE SPIRAL CABLE WITH SENSOR SUB-ASSEMBLY

14.	CHECK INSTRUMENT PANEL WIRE (TO GROUND)

(a) Disconnect the instrument panel wire connector from the airbag sensor assembly.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A26-4 (D2+) - Body ground	Always	1 MΩ or Higher
A26-3 (D2-) - Body ground	Always	1 MΩ or Higher

Text in Illustration

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

Result

Result	Proceed to
NG	A
OK	B

REPLACE INSTRUMENT PANEL WIRE

GO TO STEP 19

15.	CHECK CONNECTOR

(a) Turn the ignition switch off.

(b) Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.

OK:

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

REPLACE SPIRAL CABLE WITH SENSOR SUB-ASSEMBLY

16.	CHECK CONNECTION OF CONNECTORS

(a) Check that the spiral cable with sensor sub-assembly connectors (on the horn button assembly side) are properly connected.

OK:

The connectors are properly connected.

CONNECT CONNECTORS

17.	CHECK SPIRAL CABLE WITH SENSOR SUB-ASSEMBLY (TO B+)

(a) Disconnect the spiral cable with sensor sub-assembly connectors from the instrument panel wire and horn button assembly.

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

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
D2+ - Body ground	Ignition switch ON	Below 1 V
D2- - Body ground	Ignition switch ON	Below 1 V

Text in Illustration

*1	Driver Side Squib 2nd Step
*2	Spiral Cable with Sensor Sub-assembly
*3	Airbag Sensor Assembly
*a	Color: Black

REPLACE SPIRAL CABLE WITH SENSOR SUB-ASSEMBLY

18.	CHECK INSTRUMENT PANEL WIRE (TO B+)

(a) Turn the ignition switch off.

(b) Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.

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

(e) Turn the ignition switch to ON.

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
A26-4 (D2+) - Body ground	Ignition switch ON	Below 1 V
A26-3 (D2-) - Body ground	Ignition switch ON	Below 1 V

Text in Illustration

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

REPLACE INSTRUMENT PANEL WIRE

19.	REPLACE AIRBAG SENSOR ASSEMBLY

HINT:

If continuing from step 18, begin from (a). If continuing from any other step, begin from (c).

(a) Turn the ignition switch off.

(b) Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.

(d) Using a service wire, connect D2+ and D2- of connector E.

NOTICE:

Twist the end of the service wire in order to insert it into the connector.
Do not forcibly insert the twisted service wire into the terminals of the connector when connecting.

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

(f) Turn the ignition switch to ON, and wait for at least 60 seconds.

(g) Clear any DTCs stored in the memory (See page (h) Turn the ignition switch off. ).

(h) Turn the ignition switch off.

(i) Turn the ignition switch to ON, and wait for at least 60 seconds.

(j) Check for DTCs (See page OK: ).

OK:

DTCs B1811, B1812 and B1813 are not output.

Text in Illustration

*1	Driver Side Squib 2nd Step
*2	Spiral Cable with Sensor Sub-assembly
*3	Airbag Sensor Assembly
*4	Service Wire
*a	Color: Black

HINT:

DTCs other than B1811, B1812 or B1813 may be output at this time, but they are not related to this check.

REPLACE AIRBAG SENSOR ASSEMBLY

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

HINT:

If continuing from step 19, begin from (c). If continuing from any other step, being from (a).

(a) Turn the ignition switch off.

(b) Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.

(d) Connect the connectors to the horn button assembly.

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

(f) Turn the ignition switch to ON, and wait for at least 60 seconds.

(g) Clear any DTCs stored in the memory (See page (h) Turn the ignition switch off. ).

(h) Turn the ignition switch off.

(i) Turn the ignition switch to ON, and wait for at least 60 seconds.

(j) Check for DTCs (See page OK: ).

OK:

DTCs B1810, B1811, B1812 and B1813 are not output.

Text in Illustration

*1	Driver Side Squib 2nd Step
*2	Spiral Cable with Sensor Sub-assembly
*3	Airbag Sensor Assembly

HINT:

DTCs other than B1810, B1811, B1812 or B1813 may be output at this time, but they are not related to this check.

USE SIMULATION METHOD TO CHECK

REPLACE HORN BUTTON ASSEMBLY

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