DTC B2777, B2778, B2779, B2780

id080200803000

DTC

B2777

Passenger-side curtain air bag module system resistance low

B2778

Passenger-side curtain air bag module system resistance high

B2779

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

B2780

Passenger-side curtain air bag module system circuit short to power supply

DETECTION CONDITION

Warning
• Detection conditions are for understanding DTC outline before performing inspection. Performing inspection with only detection conditions may cause injury due to operating error or damage the system. When performing inspection, always follow inspection procedure.
• Abnormal resistance (other than 1.4-3.2 ohm) detected in passenger-side curtain air bag module circuit
• Malfunction in wiring harness between passenger-side curtain air bag module and SAS unit

POSSIBLE CAUSE

• Open or short circuit in wiring harness between 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
• Check following PID/DATA monitor, using SST (WDS or equivalent).
- PC_CURTN
• Is resistant value of passenger-side curtain air bag module normal?
- Resistance: 1.4-3.2 ohm
Yes
Present malfunction diagnosis:
• Replace SAS unit.
Past malfunction diagnosis:
• Troubleshooting completed.
No
Go to next step.
2
INSPECT PASSENGER-SIDE CURTAIN AIR BAG MODULE CONNECTOR
Warning
• Handling air bag system components improperly can accidentally deploy air bag modules and pre-tensioner seat belts, which may seriously injure you. Read AIR BAG SYSTEM SERVICE WARNINGS before handling air bag system components.
(See SERVICE WARNINGS)
• Turn ignition switch to LOCK position.
• Disconnect negative battery cable and wait for more than 1 minute.
• Disconnect passenger-side curtain air bag module connector.
• Is there cracking or chipping in passenger-side curtain air bag module connector?
Yes
Replace wiring harness.
No
Go to next step.
3
VERIFY WHETHER MALFUNCTION IS IN PASSENGER-SIDE CURTAIN AIR BAG MODULE OR RELATED WIRING HARNESS
• Connect leads of SST (Fuel and thermometer checker) or apply 2 ohm resistor to passenger-side curtain air bag module connector terminal A and B.
• Set resistance of SST (Fuel and thermometer checker) to 2 ohm.
• Connect negative battery cable.
• Turn ignition switch to ON position.
• Check following PID/DATA monitor, using SST (WDS or equivalent).
- DO_P_CURT
• Is related wiring harness normal?
Yes
Replace passenger-side curtain air bag module.
No
Replace wiring harness, then go to next step.
4
INSPECT SAS UNIT
• Turn ignition switch to LOCK position.
• Disconnect negative battery cable and wait for more than 1 minute.
• Connect passenger-side curtain air bag module connector.
• Are DTCs B2777, B2778, B2779 and/or B2780 indicated?
Yes
Present malfunction diagnosis:
• Replace SAS unit.
Past malfunction diagnosis:
• Troubleshooting completed.
No
Troubleshooting completed.