DTC B2773, B2774, B2775, B2776

id080200802900

DTC

B2773

Driver‐side curtain air bag module circuit resistance low

B2774

Driver‐side curtain air bag module circuit resistance high

B2775

Driver‐side curtain air bag module circuit short to body ground

B2776

Driver‐side curtain air bag module circuit short to power supply
DETECTION CONDITION
Warning
•  Detection conditions are for understanding the DTC outline before performing an inspection. Performing an inspection according to only the detection conditions may cause injury due to an operating error, or damage the system. When performing an inspection, always follow the inspection procedure.
•  Abnormal resistance (other than 1.4—3.2 ohms) detected in the driver-side curtain air bag module circuit
•  Malfunction in the wiring harness between the driver-side curtain air bag module and SAS control module
POSSIBLE CAUSE
•  Driver-side curtain air bag module connector malfunction
•  Driver-side curtain air bag module malfunction
•  Open circuit or short to ground in the wiring harness between the driver-side curtain air bag module and SAS control module
•  Open circuit or power supply short in the wiring harness between the driver-side curtain air bag module and SAS control module
•  SAS control module malfunction

Diagnostic procedure

Step

Inspection

Action
1
INSPECT DRIVER-SIDE CURTAIN AIR BAG MODULE CONNECTOR
•  Turn the ignition switch to the LOCK position.
•  Disconnect the negative battery cable and wait for 1 min or more.
•  Remove the following parts:
―  A-pillar trim (See A-PILLAR TRIM REMOVAL/INSTALLATION.)
―  Rear seat (See REAR SEAT REMOVAL/INSTALLATION.)
―  Tire house trim (See TIRE HOUSE TRIM REMOVAL/INSTALLATION.)
―  Rear pillar trim (See REAR PILLAR TRIM REMOVAL/INSTALLATION.)
―  Headliner (See HEADLINER REMOVAL/INSTALLATION.)
•  Disconnect the driver-side curtain air bag module connector. (See CURTAIN AIR BAG MODULE REMOVAL/INSTALLATION.)
•  Is there any malfunction of the driver-side curtain air bag module connector?
Yes
Replace the driver-side curtain air bag module wiring harness.
No
Go to the next step.
2
INSPECT DRIVER-SIDE CURTAIN AIR BAG MODULE
•  Connect the SST (Fuel and thermometer checker) or apply 2-ohm resistance to the driver-side curtain air bag module connector terminals A–B.
•  Set the SST (Fuel and thermometer checker) to 2 ohm.
•  Connect the negative battery cable.
•  Perform the DTC inspection using the M-MDS.
•  Are DTCs B2773, B2774, B2775 and/or B2776 displayed?
Yes
Go to the next step.
No
Replace the driver-side curtain air bag module. (See CURTAIN AIR BAG MODULE REMOVAL/INSTALLATION.))
3
INSPECT WIRING HARNESS BETWEEN SAS CONTROL MODULE AND DRIVER-SIDE CURTAIN AIR BAG MODULE
•  Turn the ignition switch to the LOCK position.
•  Disconnect the negative battery cable and wait for 1 min or more.
•  Disconnect the SST (Fuel and thermometer checker) or the 2 ohm resistance.
•  Disconnect all SAS control module connectors.
•  Inspect the wiring harnesses between SAS control module connector terminal 2Y and driver-side curtain air bag module connector terminal A, and SAS control module terminal 2V and driver-side curtain air bag module connector terminal B for the following:
―  Short to body ground
―  Open circuit
Note
•  Inspect for continuity while shaking the wiring harness between the SAS control module and driver-side curtain air bag module.
•  Is the wiring harness normal?
Yes
Go to the next step.
No
Replace the wiring harness between the SAS control module and the driver-side curtain air bag module.
4
INSPECT THE WIRING HARNESS BETWEEN THE SAS CONTROL MODULE AND DRIVER-SIDE CURTAIN AIR BAG MODULE FOR A SHORT CIRCUIT TO THE POWER SUPPLY
•  Connect the negative battery cable.
•  Turn the ignition switch to the ON position.
•  Measure the voltage of SAS control module connector terminals 2Y and 2V.
Note
•  Measure the voltage while shaking the wiring harness between the SAS control module and driver-side curtain air bag module.
•  Is the voltage measured?
Yes
Replace the wiring harness between the SAS control module and the driver-side curtain air bag module.
No
Go to the next step.
5
INSPECT DTCs
•  Disconnect the negative battery cable and wait for 1 min or more.
•  Connect the disconnected connector.
•  Connect the negative battery cable.
•  Clear DTCs using the M-MDS.
•  Verify DTCs using the M-MDS.
(See DTC DISPLAY.)
•  Is DTC B2773, B2774, B2775 and/or B2776 displayed again?
•  Are there other DTCs output?
Yes
Replace the SAS control module.
(See SAS CONTROL MODULE REMOVAL/INSTALLATION.)
No
DTC troubleshooting completed.