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
•  Driver-side pre-tensioner seat belt connector malfunction
•  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 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 ignition (F2, G6)/engine (WLT-1, WLT-2, WL-C, WE-C) 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.
•  Inspect the driver-side pre-tensioner seat belt connector. (Corrosion, damage, and disconnected pins)
•  Is there any malfunction of the driver-side pre-tensioner seat belt connector?
Yes
Replace the driver-side pre-tensioner seat belt wiring harness.
No
Go to the next step.
2
INSPECT WIRING HARNESS BETWEEN DRIVER-SIDE PRE-TENSIONER SEAT BELT MODULE AND SAS CONTROL MODULE
•  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 connector terminal 2S and driver-side pre-tensioner seat belt connector terminal A, SAS control module connector terminal 2P and driver-side pre-tensioner seat belt connector terminal B for the following:
―  Short circuit between terminals
―  Short to ground
―  Open circuit
Note
•  Inspect for continuity while shaking the wiring harness between the SAS control module and driver-side pre-tensioner seat belt.
•  Is the wiring harness normal?
Yes
Go to the next step.
No
Replace the wiring harness between the SAS control module and the driver-side pre-tensioner seat belt.
3
INSPECT THE WIRING HARNESS BETWEEN THE SAS CONTROL MODULE AND DRIVER-SIDE PRE-TENSIONER SEAT BELT FOR A SHORT CIRCUIT TO THE POWER SUPPLY
•  Connect the negative battery cable.
•  Turn the ignition (F2, G6)/engine (WLT-1, WLT-2, WL-C, WE-C) switch to ON position with SAS control module connector and driver-side pre-tensioner seat belt connector disconnected.
•  Measure the voltage of SAS control module connector terminals 2S and 2P.
Note
•  Measure the voltage while shaking the wiring harness between the SAS control module and driver-side pre-tensioner seat belt.
•  Is the voltage measured?
Yes
Replace the wiring harness between the SAS control module and the driver-side pre-tensioner seat belt.
No
Go to the next step.
4
INSPECT DRIVER-SIDE PRE-TENSIONER SEAT BELT
•  Turn the ignition (F2, G6)/engine (WLT-1, WLT-2, WL-C, WE-C) switch to LOCK position.
•  Disconnect the negative battery cable and wait for 1min or more.
•  Connect the SST (Fuel and thermometer checker) or apply 2 ohms resistance to the driver-side pre-tensioner seat belt connector terminals A and B.
•  Set the SST (Fuel and thermometer checker) to 2 ohms.
•  Except for the driver-side pre-tensioner seat belt connector, reconnect all disconnected connectors.
•  Connect the negative battery cable.
•  Turn the ignition (F2, G6)/engine (WLT-1, WLT-2, WL-C, WE-C) switch to ON position.
•  Clear the DTC for the SAS control module using the M-MDS.
•  Perform the DTC inspection for the SAS control module using the M-MDS.
•  Are the same DTCs present?
Yes
Go to the next step.
No
Replace the driver-side pre-tensioner seat belt.
(See SEAT BELT REMOVAL/INSTALLATION.)
5
PERFORM SAS CONTROL MODULE DTC INSPECTION
•  Turn the ignition (F2, G6)/engine (WLT-1, WLT-2, WL-C, WE-C) switch to LOCK position.
•  Disconnect the negative battery cable and wait for 1min or more.
•  Disconnect the SST (Fuel and thermometer checker) or the 2 ohms resistance.
•  Connect the driver-side pre-tensioner seat belt connector.
•  Connect the negative battery cable.
•  Turn the ignition (F2, G6)/engine (WLT-1, WLT-2, WL-C, WE-C) switch to ON position.
•  Clear the DTC for the SAS control module using the M-MDS.
•  Perform the DTC inspection for the SAS control module using the M-MDS.
•  Are the same DTCs present?
Yes
Replace the SAS control module.
(See SAS CONTROL MODULE REMOVAL/INSTALLATION.)
No
DTC troubleshooting completed.