Toyota Tundra Service Manual: Short in Passenger Side Airbag Variable Vent Hole Squib Circuit (B181A-B181D)

Toyota Tundra Service Manual / Vehicle Interior / Supplemental Restraint Systems / Airbag System / Short in Passenger Side Airbag Variable Vent Hole Squib Circuit (B181A-B181D)

DESCRIPTION

The variable vent hole squib circuit consists of the airbag sensor assembly and instrument panel passenger without door airbag assembly. The circuit instructs the SRS to deploy when the deployment conditions are met.

These DTCs are stored when a malfunction is detected in the variable vent hole squib circuit.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Warning Indicate

Test Mode / Check Mode

B181A

Short in Passenger Side Airbag Variable Vent Hole Squib Circuit

One of the following conditions is met:

  • The airbag sensor assembly detects a line short circuit signal 5 times in the variable vent hole squib circuit during the primary check.
  • A variable vent hole squib malfunction.
  • An airbag sensor assembly malfunction.
  • Instrument panel wire
  • No. 3 instrument panel wire
  • Instrument panel passenger without door airbag assembly (variable vent hole squib)
  • Airbag sensor assembly

Comes on

Applicable

B181B

Open in Passenger Side Airbag Variable Vent Hole Squib Circuit

One of the following conditions is met:

  • The airbag sensor assembly detects an open circuit signal in the variable vent hole squib circuit for 2 seconds.
  • A variable vent hole squib malfunction.
  • An airbag sensor assembly malfunction.
  • Instrument panel wire
  • No. 3 instrument panel wire
  • Instrument panel passenger without door airbag assembly (variable vent hole squib)
  • Airbag sensor assembly

Comes on

Applicable

B181C

Short to GND in Passenger Side Airbag Variable Vent Hole Squib Circuit

One of the following conditions is met:

  • The airbag sensor assembly detects a short circuit to ground signal in the variable vent hole squib circuit for 0.5 seconds.
  • A variable vent hole squib malfunction.
  • An airbag sensor assembly malfunction.
  • Instrument panel wire
  • No. 3 instrument panel wire
  • Instrument panel passenger without door airbag assembly (variable vent hole squib)
  • Airbag sensor assembly

Comes on

Applicable

B181D

Short to B+ in Passenger Side Airbag Variable Vent Hole Squib Circuit

One of the following conditions is met:

  • The airbag sensor assembly detects a short circuit to B+ signal in the variable vent hole squib circuit for 0.5 seconds.
  • A variable vent hole squib malfunction.
  • An airbag sensor assembly malfunction.
  • Instrument panel wire
  • No. 3 instrument panel wire
  • Instrument panel passenger without door airbag assembly (variable vent hole squib)
  • Airbag sensor assembly

Comes on

Applicable

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.

    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

1.

CHECK CONNECTORS

(a) Turn the ignition switch off.

*1

Instrument Panel Passenger without Door Airbag Assembly (Variable Vent Hole Squib)

*2

Airbag Sensor Assembly

*3

No. 3 Instrument Panel Wire

*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 instrument panel passenger without door airbag assembly (variable vent hole squib) and airbag sensor assembly. Also check that the connectors that link the instrument panel wire and No. 3 instrument panel wire are properly connected.

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 instrument panel passenger without door airbag assembly (variable vent hole squib) and airbag sensor assembly. Also disconnect the instrument panel wire from the No. 3 instrument panel wire.

(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 No. 3 instrument panel wire connector (on the instrument panel passenger without door airbag assembly [variable vent hole squib] side) are not 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 mechanism of the connector are not deformed or damaged.

OK:

The short springs are not deformed or damaged.

NG

REPLACE INSTRUMENT PANEL WIRE OR NO. 3 INSTRUMENT PANEL WIRE

OK

2.

CHECK INSTRUMENT PANEL PASSENGER WITHOUT DOOR AIRBAG ASSEMBLY (VARIABLE VENT HOLE SQUIB)

(a) Connect the instrument panel wire to the No. 3 instrument panel wire and airbag sensor assembly.

*1

Instrument Panel Passenger without Door Airbag Assembly (Variable Vent Hole Squib)

*2

Airbag Sensor Assembly

*3

SST

*a

Front view of wire harness connector

(to Instrument Panel Passenger without Door Airbag Assembly [Variable Vent Hole Squib])

*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 instrument panel passenger without door airbag assembly (variable vent hole squib) 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

Result

Proceed to

DTC B181A, B181B, B181C or B181D is not output

A

DTC B181A, B181B, B181C or B181D is output

B

HINT:

Codes other than DTC B181A, B181B, B181C and B181D 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 INSTRUMENT PANEL PASSENGER WITHOUT DOOR AIRBAG ASSEMBLY

B

3.

CHECK VARIABLE VENT HOLE SQUIB CIRCUIT

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

*1

Instrument Panel Passenger without Door Airbag Assembly (Variable Vent Hole Squib)

*2

Airbag Sensor Assembly

*a

Front view of wire harness connector

(to Instrument Panel Passenger without Door Airbag Assembly [Variable Vent Hole Squib])

*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:

Tester Connection

Switch Condition

Specified Condition

I3-1 (P2+) - Body ground

Ignition switch ON

Below 1 V

I3-2 (P2-) - Body ground

Ignition switch ON

Below 1 V

(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:

Tester Connection

Condition

Specified Condition

I3-1 (P2+) - I3-2 (P2-)

Always

Below 1 Ω

(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:

Tester Connection

Condition

Specified Condition

I3-1 (P2+) - Body ground

Always

1 MΩ or higher

I3-2 (P2-) - Body ground

Always

1 MΩ or higher

(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:

Tester Connection

Condition

Specified Condition

I3-1 (P2+) - I3-2 (P2-)

Always

1 MΩ or higher

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

NG

GO TO STEP 5

OK

4.

CHECK DTC

(a) Connect the connectors to the instrument panel passenger without door airbag assembly (variable vent hole squib) and airbag sensor assembly.

*1

Instrument Panel Passenger without Door Airbag Assembly (Variable Vent Hole Squib)

*2

Airbag Sensor 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

Result

Proceed to

DTC B181A, B181B, B181C or B181D is not output

A

DTC B181A, B181B, B181C or B181D is output

B

HINT:

Codes other than DTC B181A, B181B, B181C and B181D 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

5.

CHECK INSTRUMENT PANEL WIRE

(a) Disconnect the No. 3 instrument panel wire from the instrument panel wire.

*1

Instrument Panel Passenger without Door Airbag Assembly (Variable Vent Hole Squib)

*2

Airbag Sensor Assembly

*3

No. 3 Instrument Panel Wire

*4

Instrument Panel Wire

*a

Front view of wire harness connector

(to No. 3 Instrument Panel Wire)

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:

Tester Connection

Switch Condition

Specified Condition

JI2-1 (VHP+) - Body ground

Ignition switch ON

Below 1 V

JI2-2 (VHP-) - Body ground

Ignition switch ON

Below 1 V

(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:

Tester Connection

Condition

Specified Condition

JI2-1 (VHP+) - JI2-2 (VHP-)

Always

Below 1 Ω

(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:

Tester Connection

Condition

Specified Condition

JI2-1 (VHP+) - Body ground

Always

1 MΩ or higher

JI2-2 (VHP-) - Body ground

Always

1 MΩ or higher

(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:

Tester Connection

Condition

Specified Condition

JI2-1 (VHP+) - JI2-2 (VHP-)

Always

1 MΩ or higher

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

OK

REPLACE NO.3 INSTRUMENT PANEL WIRE

NG

REPLACE INSTRUMENT PANEL WIRE

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