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—3.9 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
•  Open or short circuit in the wiring harness between the driver-side curtain air bag module and SAS control module
•  Driver-side curtain air bag module malfunction
•  SAS control module malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION
1
INSPECT DRIVER‐SIDE CURTAIN AIR BAG MODULE CONNECTOR
Warning
•  Handling the air bag system components improperly can accidentally deploy the air bag modules and pre-tensioner seat belts, which may seriously injure you. Read the service warnings and cautions before handling the air bag system components.
•  Turn the ignition switch to the LOCK position.
•  Disconnect the negative battery cable and wait for 1 min or more.
•  Disconnect the driver-side curtain air bag module connector.
•  Is there any malfunction of the driver-side curtain air bag module connector?
Yes
Replace the air bag wiring harness.
No
Go to the next step.
2
VERIFY WHETHER MALFUNCTION IS IN DRIVER‐SIDE CURTAIN AIR BAG MODULE OR RELATED WIRING HARNESS
•  Connect the leads of the SST (Fuel and thermometer checker) or apply 2-ohm resistance to driver-side curtain air bag module connector terminals A and B.
•  Set the resistance of the SST (Fuel and thermometer checker) to the 2-ohm position.
•  Connect the negative battery cable.
•  Turn the ignition switch to the ON position.
•  Are DTCs B2773, B2774, B2775 and/or B2776 indicated?
Yes
Replace the air bag wiring harness, then 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
―  Short circuit between terminals
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 with SAS control module and driver-side curtain air bag module connector disconnected.
•  Measure the voltage of SAS control module connector terminals 2Y and 2V of SAS control module harness side connector.
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
•  Turn the ignition switch to the LOCK position.
•  Disconnect the negative battery cable and wait for 1min or more.
•  Reconnect all disconnected connectors.
•  Connect the negative battery cable.
•  Turn the ignition switch to the ON position.
•  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?
Yes
Replace the SAS control module.
(See SAS CONTROL MODULE REMOVAL/INSTALLATION.)
No
DTC troubleshooting completed.