DTC B1877, B1878, B1879, B1885

id0802a0801400

DTC

B1877

Driver-side pre-tensioner seat belt system circuit 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 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

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:

- DSB_P_ST
• Is the related wiring harness normal?
Yes
Replace the driver-side pre-tensioner seat belt.
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.
[Past malfunction diagnosis]
Troubleshooting completed.
No
Troubleshooting completed.