Supplemental Restraint Systems. Dtc B181A/7A Short In Passenger Side Airbag Variable Vent Hole Squib Circuit

Vehicle Interior. Yaris. Ncp93, 131

Supplemental Restraint Systems. Yaris. Ncp93, 131

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK CONNECTORS

CHECK INSTRUMENT PANEL PASSENGER AIRBAG ASSEMBLY (VARIABLE VENT HOLE SQUIB)

CHECK VARIABLE VENT HOLE CIRCUIT

CHECK DTC

CHECK INSTRUMENT PANEL WIRE

CHECK NO. 2 INSTRUMENT PANEL WIRE

DTC B181A/7A Short in Passenger Side Airbag Variable Vent Hole Squib Circuit

DTC B181B/7A Open in Passenger Side Airbag Variable Vent Hole Squib Circuit

DTC B181C/7A Short to GND in Passenger Side Airbag Variable Vent Hole Squib Circuit

DTC B181D/7A Short to B+ in Passenger Side Airbag Variable Vent Hole Squib Circuit

DESCRIPTION

The variable vent hole squib circuit consists of the airbag sensor assembly and instrument panel passenger airbag assembly.
The airbag sensor assembly uses this circuit to deploy the airbag when deployment conditions are met.
These DTCs are stored when a malfunction is detected in the variable vent hole squib circuit.

DTC No.	DTC Detection Condition	Trouble Area
B181A/7A	The airbag sensor assembly receives a line short circuit signal in the variable vent hole squib circuit during primary check. Variable vent hole squib malfunction Airbag sensor assembly malfunction	Instrument panel wire No. 2 instrument panel wire Instrument panel passenger airbag assembly (Variable vent hole squib) Airbag sensor assembly
B181B/7A	The airbag sensor assembly receives an open circuit signal in the variable vent hole squib circuit. Variable vent hole squib malfunction Airbag sensor assembly malfunction
B181C/7A	The airbag sensor assembly receives a short circuit to ground signal in the variable vent hole squib circuit. Variable vent hole squib malfunction Airbag sensor assembly malfunction
B181D/7A	The airbag sensor assembly receives a short circuit to B+ signal in the variable vent hole squib circuit. Variable vent hole squib malfunction Airbag sensor assembly malfunction

WIRING DIAGRAM

Yaris. Ncp93, 131.Supplemental Restraint Systems.Airbag System (For Sedan).
Dtc
B181A/7A Short In Passenger Side Airbag Variable Vent Hole Squib Circuit

INSPECTION PROCEDURE

HINT:

Perform the simulation method by selecting check mode (Signal Check) using the Techstream (YARIS_NCP93 RM000000XFF0B9X.html).
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 or rough road (YARIS_NCP93 RM00000135202EX.html).

1.CHECK CONNECTORS

Turn the ignition switch off.

Disconnect the cable from the negative (-) battery terminal.
CAUTION:
Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

Check that the connectors are properly connected to the instrument panel passenger airbag assembly and airbag sensor assembly. Also check that the connectors that link the instrument panel wire and No. 2 instrument panel wire are properly connected.
OK:
The connectors are properly connected.
HINT:
If the connectors are not connected securely, reconnect the connectors and proceed to the next inspection.

Disconnect the connectors from the instrument panel passenger airbag assembly and airbag sensor assembly. Also disconnect the instrument panel wire from the No. 2 instrument panel wire.

Check that the terminals of the connectors are not damaged.
OK:
The terminals are not deformed or damaged.

Check that the No. 2 instrument panel wire connector (on the instrument panel passenger airbag assembly side) is not damaged.
OK:
The lock button is not disengaged, or the claw of the lock is not deformed or damaged.

Check that the short springs for the instrument panel wire and No. 2 instrument panel wire with the activation prevention mechanism are not deformed or damaged.
OK:
The short springs are not deformed or damaged.
Text in Illustration
*1
Instrument Panel Passenger Airbag Assembly
*2
Airbag Sensor Assembly
*3
No. 2 Instrument Panel Wire
*4
Instrument Panel Wire

REPLACE WIRE HARNESS

OK

2.CHECK INSTRUMENT PANEL PASSENGER AIRBAG ASSEMBLY (VARIABLE VENT HOLE SQUIB)

Connect the instrument panel wire to the No. 2 instrument panel wire and airbag sensor assembly.

Connect SST (resistance 2.1 Ω) to connector E (green connector).
CAUTION:
Never connect the tester to the instrument panel passenger airbag assembly variable vent hole squib for measurement, as this may lead to a serious injury due to airbag deployment.
NOTICE:
1. Do not forcibly insert SST into the terminals of the connector when connecting.
2. Insert SST straight into the terminals of the connector.

SST: 09843-18061

Connect the cable to the negative (-) battery terminal.

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

Clear the DTCs stored in memory (YARIS_NCP93 RM000000XFE0F4X.html).

Turn the ignition switch off.

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

Check for DTCs (YARIS_NCP93 RM000000XFE0F4X.html).
OK:
DTC B181A/7A, B181B/7A, B181C/7A or B181D/7A is not output.
Text in Illustration
*1
Instrument Panel Passenger Airbag Assembly
*2
Airbag Sensor Assembly
*3
Connector E
*a
Front view of wire harness connector
(to Instrument Panel Passenger Airbag Assembly)
*b
Color: Green
HINT:
Codes other than DTCs B181A/7A, B181B/7A, B181C/7A and B181D/7A may be output at this time, but they are not related to this check.

Turn the ignition switch off.

Disconnect the cable from the negative (-) battery terminal.
CAUTION:
Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

Disconnect SST from connector E.

Go to step 3

REPLACE INSTRUMENT PANEL PASSENGER AIRBAG ASSEMBLY (YARIS_NCP93 RM000000V7201JX.html)

3.CHECK VARIABLE VENT HOLE CIRCUIT

Disconnect the instrument panel wire from the airbag sensor assembly.

Check for a short to B+ in the circuit.
1. Connect the cable to the negative (-) battery terminal.
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
  Q12-2 (VHP+) - Body ground
  Ignition switch ON
  Below 1 V
  Q12-1 (VHP-) - Body ground
  Ignition switch ON
  Below 1 V

Check for an open in the circuit.
1. Turn the ignition switch off.
2. Disconnect the cable from the negative (-) battery terminal.
  CAUTION:
  Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.
3. Measure the resistance according to the value(s) in the table below.
  Standard Resistance:
  Tester Connection
  Condition
  Specified Condition
  Q12-2 (VHP+) - Q12-1 (VHP-)
  Always
  Below 1 Ω

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
  Q12-2 (VHP+) - Body ground
  Always
  1 MΩ or higher
  Q12-1 (VHP-) - Body ground
  Always
  1 MΩ or higher

Check for a short in the circuit.
1. Release the activation prevention mechanism built into connector B (YARIS_NCP93 RM000000XFD0EYX.html).
2. Measure the resistance according to the value(s) in the table below.
  Standard Resistance:
  Tester Connection
  Condition
  Specified Condition
  Q12-2 (VHP+) - Q12-1 (VHP-)
  Always
  1 MΩ or higher
  Text in Illustration
  *1
  Instrument Panel Passenger Airbag Assembly
  *2
  Airbag Sensor Assembly
  *3
  Connector E
  *a
  Front view of wire harness connector
  (to Instrument Panel Passenger Airbag Assembly)
  *b
  Color: Green

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

Go to step 5

OK

4.CHECK DTC

Connect the connectors to the instrument panel passenger airbag assembly and airbag sensor assembly.

Connect the cable to the negative (-) battery terminal.

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

Clear the DTCs stored in memory (YARIS_NCP93 RM000000XFE0F4X.html).

Turn the ignition switch off.

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

Check for DTCs (YARIS_NCP93 RM000000XFE0F4X.html).
OK:
DTC B181A/7A, B181B/7A, B181C/7A or B181D/7A is not output.
Text in Illustration
*1
Instrument Panel Passenger Airbag Assembly
*2
Airbag Sensor Assembly
HINT:
Codes other than DTCs B181A/7A, B181B/7A, B181C/7A and B181D/7A may be output at this time, but they are not related to this check.

REPLACE AIRBAG SENSOR ASSEMBLY (YARIS_NCP93 RM000000V6U02AX.html)

USE SIMULATION METHOD TO CHECK (YARIS_NCP93 RM00000135202EX.html)

5.CHECK INSTRUMENT PANEL WIRE

Disconnect the No. 2 instrument panel wire from the instrument panel wire.

Check for a short to B+ in the circuit.
1. Connect the cable to the negative (-) battery terminal.
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
  DQ4-1 (VHP+) - Body ground
  Ignition switch ON
  Below 1 V
  DQ4-2 (VHP-) - Body ground
  Ignition switch ON
  Below 1 V

Check for an open in the circuit.
1. Turn the ignition switch off.
2. Disconnect the cable from the negative (-) battery terminal.
  CAUTION:
  Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.
3. Measure the resistance according to the value(s) in the table below.
  Standard Resistance:
  Tester Connection
  Condition
  Specified Condition
  DQ4-1 (VHP+) - DQ4-2 (VHP-)
  Always
  Below 1 Ω

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
  DQ4-1 (VHP+) - Body ground
  Always
  1 MΩ or higher
  DQ4-2 (VHP-) - Body ground
  Always
  1 MΩ or higher

Check for a short in the circuit.

Release the activation prevention mechanism built into connector B (YARIS_NCP93 RM000000XFD0EYX.html).

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
DQ4-1 (VHP+) - DQ4-2 (VHP-)	Always	1 MΩ or higher

Text in Illustration
*1	Instrument Panel Passenger Airbag Assembly
*2	Airbag Sensor Assembly
*3	No. 2 Instrument Panel Wire
*4	Instrument Panel Wire
*5	Connector C
*a	Front view of wire harness connector (to No. 2 Instrument Panel Wire)

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

REPLACE INSTRUMENT PANEL WIRE

OK

6.CHECK NO. 2 INSTRUMENT PANEL WIRE

Check for a short to B+ in the circuit.
1. Connect the cable to the negative (-) battery terminal.
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
  Q12-2 (VHP+) - Body ground
  Ignition switch ON
  Below 1 V
  Q12-1 (VHP-) - Body ground
  Ignition switch ON
  Below 1 V

Check for an open in the circuit.
1. Turn the ignition switch off.
2. Disconnect the cable from the negative (-) battery terminal.
  CAUTION:
  Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.
3. Measure the resistance according to the value(s) in the table below.
  Standard Resistance:
  Tester Connection
  Condition
  Specified Condition
  Q12-2 (VHP+) - Q12-1 (VHP-)
  Always
  Below 1 Ω

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
  Q12-2 (VHP+) - Body ground
  Always
  1 MΩ or higher
  Q12-1 (VHP-) - Body ground
  Always
  1 MΩ or higher

Check for a short in the circuit.

Release the activation prevention mechanism built into connector D (YARIS_NCP93 RM000000XFD0EYX.html).

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
Q12-2 (VHP+) - Q12-1 (VHP-)	Always	1 MΩ or higher

Text in Illustration
*1	Instrument Panel Passenger Airbag Assembly
*2	Airbag Sensor Assembly
*3	No. 2 Instrument Panel Wire
*4	Instrument Panel Wire
*5	Connector E
*a	Front view of wire harness connector (to Instrument Panel Passenger Airbag Assembly)
*b	Color: Green

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

REPLACE NO. 2 INSTRUMENT PANEL WIRE

USE SIMULATION METHOD TO CHECK (YARIS_NCP93 RM00000135202EX.html)

Tester Connection	Switch Condition	Specified Condition
Q12-2 (VHP+) - Body ground	Ignition switch ON	Below 1 V
Q12-1 (VHP-) - Body ground	Ignition switch ON	Below 1 V