DTC B1877, B1878, B1879, B1885

id080200801400

DTC
B1877
Driver‐side pre-tensioner seat belt system resistance high
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 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.
•  Resistance other than 1.5—3.1 ohms detected in driver‐side pre-tensioner seat belt circuit
•  Malfunction in the wiring harness between driver-side pre-tensioner seat belt and SAS control module
POSSIBLE CAUSE
•  Open or short circuit in wiring harness between 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
1
INSPECT DRIVER‐SIDE PRE-TENSIONER SEAT BELT
•  Using the M-MDS, verify the following PID/DATA monitor.
―  DR_PTENS
•  Is the resistance of the driver-side pre-tensioner seat belt normal?
―  Resistance: 1.5—3.1 ohms
Yes
Replace the SAS control module.
(See SAS CONTROL MODULE REMOVAL/INSTALLATION.)
No
Go to the next step.
2
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 and cautions before handling the air bag system components.
•  Turn the engine switch to LOCK position.
•  Disconnect the negative battery cable and wait for 1 min or more.
•  Disconnect the driver-side pre-tensioner seat belt connector.
•  Is there any malfunction of the driver-side pre-tensioner seat belt connector?
Yes
Replace the air bag wiring harness.
No
Go to the 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 connector terminal A and B.
•  Set resistance of SST (Fuel and thermometer checker) to the 2-ohm position.
•  Connect the negative battery cable.
•  Turn the engine switch to ON position.
•  Are DTCs B1877, B1878, B1879, and/or B1885 indicated?
Yes
Go to the next step.
No
Replace the driver-side pre-tensioner seat belt.
(See SIDE AIR BAG MODULE REMOVAL/INSTALLATION.)
4
INSPECT WIRING HARNESS BETWEEN DRIVER-SIDE PRE-TENSIONER SEAT BELT MODULE AND SAS CONTROL MODULE
•  Turn the engine switch to the LOCK position.
•  Disconnect the negative battery cable and wait for 1 min or more.
•  Disconnect the driver-side pre-tensioner seat belt connector.
•  Remove the console.
•  Disconnect the SAS control module connectors.
•  Inspect the wiring harness between SAS control module terminal 2S and driver-side pre-tensioner seat belt terminal A, SAS control module terminal 2P and driver-side pre-tensioner seat belt terminal B for the following:
―  Short to ground
―  Short to power supply
―  Open circuit
•  Is the wiring harness normal?
Yes
Go to the next step.
No
Replace the air bag wiring harness.
5
INSPECT AIR BAG SYSTEM WARNING LIGHT
•  Connect the all SAS control module connectors.
•  Connect the driver and passenger-side pre-tensioner seat belt connectors.
•  Connect the negative battery cable.
•  Turn the engine switch to ON position.
•  Are DTCs B1877, B1878, B1879, and/or B1885 indicated?
Yes
Replace the SAS control module.
(See SAS CONTROL MODULE REMOVAL/INSTALLATION.)
No
The system is normal at present. (Clear the malfunction from the memory.)