Diagnostic procedure

WARNING: This page is about a different car, the 2005 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

DTC B2777, B2778, B2779, B2780 DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	INSPECT PASSENGER-SIDE CURTAIN AIR BAG MODULE Check the following PID/DATA monitor, using SST (WDS or equivalent). (See PID/DATA MONITOR TABLE .) PS_CURTN Is resistance of passenger-side curtain air bag module normal? Resistance: 1.4-3.2 ohms	Yes	Present malfunction diagnosis: Replace SAS control module. (See SAS CONTROL MODULE REMOVAL/INSTALLATION .) Past malfunction diagnosis: Troubleshooting completed.
1		No	Go to next step.
2	INSPECT PASSENGER-SIDE CURTAIN AIR BAG MODULE CONNECTOR WARNING: Handling the air bag system components improperly can accidentally operate (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 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.
2		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 terminal A and B. Set resistance of SST (Fuel and thermometer checker) to 2 ohms. Connect negative battery cable. Turn ignition switch to ON position. Are any one or all of the following DTCs displayed? B2777 B2778 B2779 B2780	Yes	Replace wiring harness, then go to next step.
3		No	Replace passenger-side curtain air bag module. (See CURTAIN AIR BAG MODULE REMOVAL/INSTALLATION [SEDAN] .) (See CURTAIN AIR BAG MODULE REMOVAL/INSTALLATION [5-DOOR, SPORT WAGON] .)
4	INSPECT SAS CONTROL MODULE 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 any one or all of the following DTCs displayed? B2777 B2778 B2779 B2780	Yes	Present malfunction diagnosis: Replace SAS control module. (See SAS CONTROL MODULE REMOVAL/INSTALLATION .) Past malfunction diagnosis: Troubleshooting completed.
4		No	Troubleshooting completed.