DTC B2777, B2778, B2779, B2780


BHE080201046W28

DTC

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.
• Abnormal resistance (other than 1.4-3.2 ohms ) detected in the passenger-side curtain air bag module circuit
• Malfunction in the wiring harness between the passenger-side curtain air bag module and SAS unit

POSSIBLE CAUSE

• Open or short circuit in the wiring harness between the passenger-side curtain air bag module and SAS unit
• Passenger-side curtain air bag module malfunction
• SAS unit malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION

1

INSPECT PASSENGER-SIDE CURTAIN AIR BAG MODULE

• Using the WDS or equivalent, verify the following PID/DATA monitor.
– PS_CURTN
• Is the resistance of the passenger-side curtain air bag module normal?
– Resistance: 1.4-3.2 ohms
Yes

[Present malfunction diagnosis]

• Replace the SAS unit.

[Past malfunction diagnosis]

• DTC troubleshooting completed.
No
Go to the next step.
2

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.
(See SERVICE WARNINGS.)
(See SERVICE CAUTIONS.)
• Turn the ignition switch to the LOCK position.
• Disconnect the negative battery cable and wait for 1 min or more.
• Disconnect the passenger-side curtain air bag module connector.
• 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.
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.
• Using the WDS or equivalent, verify the following PID/DATA monitor.
– OD_P_CURT
• Are related wiring harnesses normal?
Yes
Replace the passenger-side curtain air bag module.
No
Replace the air bag wiring harness, then go to the next step.
4

INSPECT SAS UNIT

• Turn the ignition switch to the LOCK position.
• Disconnect the negative battery cable and wait for 1 min or more.
• Connect the passenger-side curtain air bag module connector.
• Are DTCs B2777, B2778, B2779 and/or B2780 indicated?
Yes

[Present malfunction diagnosis]

• Replace the SAS unit.

[Past malfunction diagnosis]

• DTC troubleshooting completed.
No
DTC troubleshooting completed.