B181C

SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM: B181A/7A-B181D/7A:

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

DESCRIPTION

The variable vent hole squib circuit consists of the center airbag sensor and front passenger airbag.

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.





WIRING DIAGRAM





INSPECTION PROCEDURE

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

HINT
To perform the simulation method, enter check mode (signal check) with the Techstream Check Mode Procedure, and then wiggle each connector of the airbag system or drive the vehicle on various types of road Diagnosis System.

PROCEDURE

1. CHECK FRONT PASSENGER AIRBAG (VARIABLE VENT HOLE SQUIB)

(a) Turn the ignition switch off.





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

(c) Disconnect the connectors from the front passenger airbag.

(d) Connect the white wire side of SST (resistance: 2.1 Ohms) to connector G (green connector).

CAUTION:
Never connect the tester to the front passenger airbag (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

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

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

(g) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(h) Turn the ignition switch off.

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

(j) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

OK:

DTC B181A, B181B, B181C or B181D is not output.

HINT
Codes other than DTC B181A, B181B, B181C and B181D may be output at this time, but they are not related to this check.

Text in Illustration





NG -- CHECK CONNECTOR

OK -- REPLACE FRONT PASSENGER AIRBAG ASSEMBLY Removal

2. CHECK CONNECTOR

(a) Turn the ignition switch off.

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

(c) Disconnect SST from connector G.

(d) Disconnect the connectors from the center airbag sensor.

(e) Check that the connectors (on the center airbag sensor side and front passenger airbag side) are not damaged.

OK:

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





Text in Illustration





NG -- REPLACE HARNESS AND CONNECTOR
OK -- Continue to next step.

3. CHECK VARIABLE VENT HOLE SQUIB CIRCUIT

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





(b) Turn the ignition switch to ON.

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

Standard Voltage:





(d) Turn the ignition switch off.

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

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

Standard Resistance:





(g) Release the activation prevention mechanism built into connector B Diagnosis System.

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

Standard Resistance:





Text in Illustration





NG -- CHECK VARIABLE VENT HOLE SQUIB CIRCUIT
OK -- Continue to next step.

4. CHECK CENTER AIRBAG SENSOR

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





(b) Connect the connectors to the front passenger airbag and center airbag sensor.

(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 Reading and Clearing Diagnostic Trouble Codes.

(f) Turn the ignition switch off.

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

(h) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

Result





HINT
Codes other than DTC B181A, B181B, B181C and B181D may be output at this time, but they are not related to this check.

Text in Illustration





A -- REPLACE CENTER AIRBAG SENSOR ASSEMBLY Removal

B -- USE SIMULATION METHOD TO CHECK Diagnosis System

5. CHECK VARIABLE VENT HOLE SQUIB CIRCUIT

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





(b) Disconnect the instrument panel wire connector from the No. 2 instrument panel wire.

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

(d) Turn the ignition switch to ON.

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

Standard Voltage:





(f) Turn the ignition switch off.

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

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

Standard Resistance:





(i) Release the activation prevention mechanism built into connector B Diagnosis System.

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

Standard Resistance:





Text in Illustration





NG -- CHECK NO. 2 FLOOR WIRE (CENTER AIRBAG SENSOR - INSTRUMENT PANEL WIRE)

OK -- REPLACE NO. 2 INSTRUMENT PANEL WIRE

6. CHECK NO. 2 FLOOR WIRE (CENTER AIRBAG SENSOR - INSTRUMENT PANEL WIRE)

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





(b) Disconnect the instrument panel wire connector from the instrument panel wire.

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

(d) Turn the ignition switch to ON.

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

Standard Voltage:





(f) Turn the ignition switch off.

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

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

Standard Resistance:





(i) Release the activation prevention mechanism built into connector B Diagnosis System.

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

Standard Resistance:





Text in Illustration





NG -- REPLACE NO. 2 FLOOR WIRE

OK -- REPLACE INSTRUMENT PANEL WIRE