Toyota Tacoma (2015-2018) Service Manual: Short in Front Passenger Side Squib Circuit (B1805/52-B1808/52)

Toyota Tacoma (2015-2018) Service Manual / Supplemental Restraint Systems / Airbag System / Short in Front Passenger Side Squib Circuit (B1805/52-B1808/52)

DESCRIPTION

The front passenger side squib circuit consists of the airbag sensor assembly and the instrument panel passenger without door airbag assembly.

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

These DTCs are recorded when a malfunction is detected in the front passenger side squib circuit.

DTC No.	DTC Detection Condition	Trouble Area
B1805/52	The airbag sensor assembly receives a line short circuit in the front passenger side squib circuit for 2 seconds. Front passenger side squib malfunction Airbag sensor assembly malfunction	Instrument panel wire Instrument panel wire assembly Instrument panel passenger without door airbag assembly (Front passenger side squib) Airbag sensor assembly
B1806/52	The airbag sensor assembly receives an open circuit signal in the front passenger side squib circuit for 2 seconds. Front passenger side squib malfunction Airbag sensor assembly malfunction	Instrument panel wire Instrument panel wire assembly Instrument panel passenger without door airbag assembly (Front passenger side squib) Airbag sensor assembly
B1807/52	The airbag sensor assembly receives a short circuit to ground signal in the front passenger side squib circuit for 0.5 seconds. Front passenger side squib malfunction Airbag sensor assembly malfunction	Instrument panel wire Instrument panel wire assembly Instrument panel passenger without door airbag assembly (Front passenger side squib) Airbag sensor assembly
B1808/52	The airbag sensor assembly receives a short circuit to B+ signal in the front passenger side squib circuit for 0.5 seconds. Front passenger side squib malfunction Airbag sensor assembly malfunction	Instrument panel wire Instrument panel wire assembly Instrument panel passenger without door airbag assembly (Front passenger side squib) 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 B1805 is output.	A
DTC B1806 is output.	B
DTC B1807 is output.	C
DTC B1808 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.

(c) Check that the instrument panel wire assembly connectors (on the instrument panel passenger without door airbag assembly side) are not damaged.

OK:

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

REPLACE INSTRUMENT PANEL WIRE ASSEMBLY

3.	CHECK CONNECTION OF CONNECTORS

(a) Check that the connectors are properly connected to the airbag sensor assembly and the instrument panel wire assembly.

OK:

The connectors are properly connected.

CONNECT CONNECTORS

4.	CHECK INSTRUMENT PANEL WIRE ASSEMBLY (FOR SHORT)

(a) Disconnect the instrument panel wire assembly connectors from the instrument panel wire and instrument panel passenger without door airbag 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
A25-1 (P+) - A25-2 (P-)	Always	1 MΩ or Higher

Text in Illustration

*1	Front Passenger Side Squib
*2	Airbag Sensor Assembly
*a	Color: Orange

REPLACE INSTRUMENT PANEL WIRE 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
IG1-1 (P+) - IG1-2 (P-)	Always	1 MΩ or Higher

Text in Illustration

*1	Front Passenger Side Squib
*2	Instrument Panel Wire 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 instrument panel wire 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 B1805 is not output.

Text in Illustration

*1	Front Passenger Side Squib
*2	Airbag Sensor Assembly

HINT:

DTCs other than B1805 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.

(c) Check that the instrument panel wire assembly connectors (on the instrument panel passenger without door airbag assembly side) are not damaged.

OK:

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

REPLACE INSTRUMENT PANEL WIRE ASSEMBLY

8.	CHECK CONNECTORS

(a) Check that the connectors are properly connected to the airbag sensor assembly and the instrument panel wire assembly.

OK:

The connectors are properly connected.

CONNECT CONNECTORS

9.	CHECK INSTRUMENT PANEL WIRE ASSEMBLY (FOR OPEN)

(a) Disconnect the instrument panel wire assembly connectors from the instrument panel wire and instrument panel passenger without door airbag assembly.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A25-1 (P+) - A25-2(P-)	Always	Below 1 Ω

Text in Illustration

*1	Front Passenger Side Squib
*2	Airbag Sensor Assembly
*a	Color: Orange

REPLACE INSTRUMENT PANEL WIRE 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
IG1-1 (P+) - IG1-2 (P-)	Always	Below 1 Ω

Text in Illustration

*1	Front Passenger Side Squib
*2	Instrument Panel Wire 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.

(c) Check that the instrument panel wire assembly connectors (on the instrument panel passenger without door airbag assembly side) are not damaged.

OK:

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

REPLACE INSTRUMENT PANEL WIRE ASSEMBLY

12.	CHECK CONNECTION OF CONNECTORS

(a) Check that the connectors are properly connected to the airbag sensor assembly and the instrument panel wire assembly.

OK:

The connectors are properly connected.

CONNECT CONNECTORS

13.	CHECK INSTRUMENT PANEL WIRE ASSEMBLY (TO GROUND)

(a) Disconnect the instrument panel wire assembly connectors from the instrument panel wire and instrument panel passenger without door airbag assembly.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A25-1 (P+) - Body ground	Always	1 MΩ or Higher
A25-2(P-) - Body ground	Always	1 MΩ or Higher

Text in Illustration

*1	Front Passenger Side Squib
*2	Airbag Sensor Assembly
*a	Color: Orange

REPLACE INSTRUMENT PANEL WIRE 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
IG1-1 (P+) - Body ground	Always	1 MΩ or Higher
IG1-2 (P-) - Body ground	Always	1 MΩ or Higher

Text in Illustration

*1	Front Passenger Side Squib
*2	Instrument Panel Wire 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.

(c) Check that the instrument panel wire assembly connectors (on the instrument panel passenger without door airbag assembly side) are not damaged.

OK:

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

REPLACE INSTRUMENT PANEL WIRE ASSEMBLY

16.	CHECK CONNECTION OF CONNECTORS

(a) Check that the connectors are properly connected to the airbag sensor assembly and the instrument panel wire assembly.

OK:

The connectors are properly connected.

CONNECT CONNECTORS

17.	CHECK INSTRUMENT PANEL WIRE ASSEMBLY (TO B+)

(a) Disconnect the instrument panel wire assembly connectors from the instrument panel wire and instrument panel passenger without door airbag 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
A25-1 (P+) - Body ground	Ignition switch ON	Below 1 V
A25-2(P-) - Body ground	Ignition switch ON	Below 1 V

Text in Illustration

*1	Front Passenger Side Squib
*2	Airbag Sensor Assembly
*a	Color: Orange

REPLACE INSTRUMENT PANEL WIRE 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
IG1-1 (P+) - Body ground	Ignition switch ON	Below 1 V
IG1-2 (P-) - Body ground	Ignition switch ON	Below 1 V

Text in Illustration

*1	Front Passenger Side Squib
*2	Instrument Panel Wire Assembly
*3	Instrument Panel Wire
*4	Airbag Sensor Assembly

REPLACE INSTRUMENT PANEL WIRE

19.	CHECK 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 A25-1 (P+) and A25-2 (P-) 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:

DTC B1806, B1807 and B1808 are not output.

Text in Illustration

*1	Front Passenger Side Squib
*2	Airbag Sensor Assembly
*3	Service Wire
*a	Color: Orange

HINT:

DTCs other than B1806, B1807 or B1808 may be output at this time, but they are not related to this check.

REPLACE AIRBAG SENSOR ASSEMBLY

20.	CHECK INSTRUMENT PANEL PASSENGER WITHOUT DOOR AIRBAG ASSEMBLY (FRONT PASSENGER SIDE SQUIB)

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 instrument panel passenger without door airbag 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 B1805, B1806, B1807 and B1808 are not output.

Text in Illustration

*1	Front Passenger Side Squib
*2	Airbag Sensor Assembly

HINT:

DTCs other than B1805, B1806, B1807 or B1808 may be output at this time, but they are not related to this check.

USE SIMULATION METHOD TO CHECK

REPLACE INSTRUMENT PANEL PASSENGER WITHOUT DOOR AIRBAG ASSEMBLY

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