Toyota Tundra Service Manual: Short in D Squib Circuit (B1800-B1803)

DESCRIPTION

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

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

These DTCs are stored when a malfunction is detected in the driver side squib circuit.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

• When installing the spiral with sensor cable sub-assembly and steering wheel, be sure to adjust the spiral with sensor cable sub-assembly as it may break if the steering wheel is turned before adjusting the spiral with sensor cable sub-assembly.

  Click here

• 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.

  Click here

• When disconnecting the cable from the negative (-) battery terminal while performing repairs, some systems need to be initialized after the cable is reconnected.

  Click here

HINT:

To perform the simulation method, enter check mode (signal check) with the Techstream (Click here ), and then wiggle each connector of the airbag system or drive the vehicle on various types of road (Click here ).

PROCEDURE

(a) Turn the ignition switch off.

*1 Horn Button Assembly *2 Airbag Sensor Assembly *3 Spiral with Sensor Cable Sub-assembly *4 Instrument Panel Wire

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

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

OK:

The connectors are properly connected.

HINT:

If the connectors are not properly connected, reconnect the connectors and proceed to the next inspection.

(d) Disconnect the connectors from the horn button assembly, spiral with sensor cable sub-assembly and airbag sensor assembly.

(e) Check that the terminals of the connectors are not deformed or damaged.

OK:

The terminals are not deformed or damaged.

(f) Check that the spiral with sensor cable sub-assembly connector (on the horn button assembly side) is not loose, deformed or damaged.

OK:

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

(g) Check that the short springs of the activation prevention mechanisms of the instrument panel wire connector and spiral with sensor cable sub-assembly connector are not deformed or damaged.

OK:

The short springs are not deformed or damaged.

NG

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

OK

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

*1 Horn Button Assembly *2 Airbag Sensor Assembly *3 Spiral with Sensor Cable Sub-assembly *4 SST *a Front view of wire harness connector (to Horn Button Assembly) *b Color: Orange

(b) Connect the white wire side of SST (resistance: 2.1 Ω) to connector E (orange connector).

CAUTION:

Never connect the tester to the horn button assembly for measurement, as this may lead to a serious injury due to airbag deployment.

NOTICE:

• 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

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

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

(e) Clear the DTCs.

Click here

(f) Turn the ignition switch off.

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

(h) Check for DTCs.

Click here

HINT:

Codes other than DTC B1800, B1801, B1802 and B1803 may be output at this time, but they are not related to this check.

(i) Turn the ignition switch off.

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

(k) Disconnect SST from connector E.

A

REPLACE HORN BUTTON ASSEMBLY

B

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

*1	Horn Button Assembly
*2	Airbag Sensor Assembly
*3	Spiral with Sensor Cable Sub-assembly
*4	Instrument Panel Wire
*a	Front view of wire harness connector (to Horn Button Assembly)
*b	Color: Orange
	Release the activation prevention mechanism

(b) Check for a short to B+ in the circuit.

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

(2) Turn the ignition switch to ON.

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

Standard Voltage:

(4) Turn the ignition switch off.

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

(c) Check for an open in the circuit.

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

Standard Resistance:

(d) Check for a short to ground in the circuit.

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

Standard Resistance:

(e) Check for a short in the circuit.

(1) Release the activation prevention mechanism built into connector B.

Click here

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

Standard Resistance:

(3) Restore the released activation prevention mechanism of connector B to the original condition.

NG

GO TO STEP 5

OK

(a) Connect the connectors to the horn button assembly and airbag sensor assembly.

*1 Horn Button Assembly *2 Airbag Sensor Assembly *3 Spiral with Sensor Cable Sub-assembly

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

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

(d) Clear the DTCs.

Click here

(e) Turn the ignition switch off.

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

(g) Check for DTCs.

Click here

HINT:

Codes other than DTC B1800, B1801, B1802 and B1803 may be output at this time, but they are not related to this check.

A

USE SIMULATION METHOD TO CHECK

B

REPLACE AIRBAG SENSOR ASSEMBLY

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

*1	Horn Button Assembly
*2	Airbag Sensor Assembly
*3	Spiral with Sensor Cable Sub-assembly
*4	Instrument Panel Wire
*a	Front view of wire harness connector (to Spiral with Sensor Cable Sub-assembly)
	Release the activation prevention mechanism

(b) Check for a short to B+ in the circuit.

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

(2) Turn the ignition switch to ON.

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

Standard Voltage:

(4) Turn the ignition switch off.

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

(c) Check for an open in the circuit.

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

Standard Resistance:

(d) Check for a short to ground in the circuit.

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

Standard Resistance:

(e) Check for a short in the circuit.

(1) Release the activation prevention mechanism built into connector B.

Click here

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

Standard Resistance:

(3) Restore the released activation prevention mechanism of connector B to the original condition.

OK

REPLACE SPIRAL WITH SENSOR CABLE SUB-ASSEMBLY

NG

REPLACE INSTRUMENT PANEL WIRE