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 B1877, B1878, B1879, B1885 DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	INSPECT DRIVER-SIDE PRE-TENSIONER SEAT BELT Check the following PID/DATA monitor, using SST (WDS or equivalent) (See PID/DATA MONITOR TABLE .) DR_PTENS Is resistance of driver-side pre-tensioner seat belt normal? Resistance: 1.5-3.1 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 DRIVER-SIDE PRE-TENSIONER SEAT BELT 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. Remove driver-side B-pillar lower trim. Disconnect driver-side pre-tensioner seat belt connector. Is there cracking or chipping in driver-side pre-tensioner seat belt connector?	Yes	Replace wiring harness.
2		No	Go to next step.
3	VERIFY WHETHER MALFUNCTION IS IN DRIVER-SIDE PRE-TENSIONER SEAT BELT OR RELATED WIRING HARNESS Connect leads of SST (Fuel and thermometer checker) or apply 2-ohm resistor to driver-side pre-tensioner seat belt 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. Check the following PID/DATA monitor, using SST (WDS or equivalent). (See PID/DATA MONITOR TABLE .) DSB_P_ST Is related wiring harness normal?	Yes	Replace driver-side pre-tensioner seat belt. (See FRONT SEAT BELT REMOVAL/INSTALLATION .)
3		No	Replace wiring harness, then go to next step.
4	INSPECT SAS CONTROL MODULE Turn ignition switch to LOCK position. Disconnect negative battery cable and wait for more than 1 minute. Connect driver-side pre-tensioner seat belt connector. Are any one or all of the following DTCs displayed? B1877 B1878 B1879 B1885	Yes	Present malfunction diagnosis: Replace SAS control module. (See SAS CONTROL MODULE REMOVAL/INSTALLATION .) Past malfunction diagnosis: Troubleshooting completed.
4		No	Troubleshooting completed.