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DTC B1877, B1878, B1879, B1885

id0802a0801400

DTC | B1877 | Driver-side pre-tensioner seat belt system circuit resistance high
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B1878 | Driver-side pre-tensioner seat belt system circuit short to power supply
B1879 | Driver-side pre-tensioner seat belt system circuit short to ground
B1885 | Driver-side pre-tensioner seat belt system circuit resistance low
DETECTION CONDITION | Warning • Detection conditions are for understanding the DTC outline before performing an inspection. Performing an inspection with only 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 1.9-2.6 ohms) detected in the driver-side pre-tensioner seat belt circuit • Malfunction in the wiring harness between the driver-side pre-tensioner seat belt and SAS control module
POSSIBLE CAUSE | • Open or short circuit in the wiring harness between the driver-side pre-tensioner seat belt and SAS control module • Driver-side pre-tensioner seat belt malfunction • SAS control module malfunction

Diagnostic procedure

Step | Inspection | Action
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1 | INSPECT DRIVER-SIDE PRE-TENSIONER SEAT BELT 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 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. • Remove the driver-side B-pillar lower trim. • Disconnect the driver-side pre-tensioner seat belt connector. • Is there cracking or chipping in the driver-side pre-tensioner seat belt connector? | Yes | Replace the air bag wiring harness.
No | Go to the next step.
2 | VERIFY WHETHER MALFUNCTION IS IN DRIVER-SIDE PRE-TENSIONER SEAT BELT OR RELATED WIRING HARNESS • Connect the leads of the SST (Fuel and thermometer checker) or apply 2-ohm resistance to driver-side pre-tensioner seat belt connector terminals A and B. • Set 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, check the following PID/DATA monitor: (See PID/DATA MONITOR TABLE.) - DSB_P_ST • Is the related wiring harness normal? | Yes | Replace the driver-side pre-tensioner seat belt. (See FRONT SEAT BELT REMOVAL/INSTALLATION.)
No | Replace the air bag wiring harness, then go to the next step.
3 | INSPECT SAS CONTROL MODULE • Turn the ignition switch to the LOCK position. • Disconnect the negative battery cable and wait for 1 min or more. • Connect the 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 the SAS control module. (See SAS CONTROL MODULE REMOVAL/INSTALLATION.) [Past malfunction diagnosis] Troubleshooting completed.
No | Troubleshooting completed.