DTC B1056, B2777, B2778, B2779, B2780

id080200809500

DTC

B1056

Passenger-side curtain air bag module and other air bag module circuits short

B2777

Passenger-side curtain air bag module circuit resistance low

B2778

Passenger-side curtain air bag module circuit resistance high

B2779

Passenger-side curtain air bag module circuit short to body ground

B2780

Passenger-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.
•  Resistance other than 0.9—10.36 ohms detected in passenger-side curtain air bag module circuit
•  Malfunction in wiring harness between passenger-side curtain air bag module and SAS control module
POSSIBLE CAUSE
•  Open or short circuit in wiring harness between passenger-side curtain air bag module and SAS control module
•  Passenger-side curtain air bag module malfunction
•  SAS control module malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION
1
INSPECT PASSENGER-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 OFF position.
•  Disconnect the negative battery cable and wait for 1 min or more.
•  Disconnect the passenger-side curtain air bag module connectors. (See CURTAIN AIR BAG MODULE REMOVAL/INSTALLATION.)
•  Is there any malfunction of the passenger-side curtain air bag module connector?
Yes
Replace the air bag wiring harness.
No
Go to the next step.
2
INSPECT WIRING HARNESS BETWEEN PASSENGER-SIDE CURTAIN AIR BAG MODULE AND SAS CONTROL MODULE
•  Turn the ignition switch to the OFF position.
•  Disconnect the negative battery cable and wait for 1 min or more.
•  Remove the column cover. (See COLUMN COVER REMOVAL/INSTALLATION.)
•  Disconnect the clock spring connector. (See COMBINATION SWITCH REMOVAL/INSTALLATION.)
•  Remove the glove compartment. (See GLOVE COMPARTMENT REMOVAL/INSTALLATION.)
•  Disconnect the passenger-side air bag module connector. (See PASSENGER-SIDE AIR BAG MODULE REMOVAL/INSTALLATION.)
•  Disconnect the driver and passenger-side front seat connectors. (See FRONT SEAT REMOVAL/INSTALLATION.)
•  Disconnect the driver-side curtain air bag module connector. (See CURTAIN AIR BAG MODULE REMOVAL/INSTALLATION.)
•  Remove the B-pillar lower trim. (See B-PILLAR LOWER TRIM REMOVAL/INSTALLATION.)
•  Disconnect the driver and passenger-side pre-tensioner seat belt connectors. (See FRONT SEAT BELT REMOVAL/INSTALLATION.)
•  Disconnect the SAS control module connectors. (See SAS CONTROL MODULE REMOVAL/INSTALLATION.)
•  Inspect the wiring harness between SAS control module terminal 2AL and passenger-side curtain air bag module terminal A, SAS control module terminal 2AH and passenger-side curtain air bag module terminal B for the following:
―  Short to ground
―  Short to power supply
―  Open circuit
Note
•  Inspect for continuity while shaking the wiring harness between the passenger-side curtain air bag module and SAS control module.
•  Is the wiring harness normal?
Yes
Go to the next step.
No
Replace the air bag wiring harness.
3
VERIFY WHETHER MALFUNCTION IS IN PASSENGER-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 passenger-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 B1056, B2777, B2778, B2779 and/or B2780 indicated?
Yes
Go to the next step.
No
Replace the passenger-side curtain air bag module.
(See CURTAIN AIR BAG MODULE REMOVAL/INSTALLATION.)
4
INSPECT DTCs
•  Clear DTCs using the M-MDS.
(See CLEARING DTC.)
•  Verify DTCs using the M-MDS.
(See DTC DISPLAY.)
•  Is DTC B1056, B2777, B2778, B2779 and/or B2780 displayed again?
•  Are there other DTCs output?
Yes
Replace the SAS control module.
(See SAS CONTROL MODULE REMOVAL/INSTALLATION.)
No
DTC troubleshooting completed.