DTC B1878

id080200803700

System Malfunction Location

• Driver-side pre-tensioner front buckle circuit short to power supply

Detection Condition

Warning
• Detection conditions are for understanding the DTC outline before performing an inspection. Performing an inspection according to only the detection conditions may cause injury due to an operating error, or damage the system. When performing an inspection, always follow the inspection procedure.

• The SAS control module monitors the driver-side pre-tensioner front buckle circuit. If the SAS control module detects a short to power supply, it will output a pattern 17 flash to the air bag system warning light, and store DTC B1878 in memory.

Possible Cause

• Short to wiring harness power supply between the SAS control module and the driver-side pre-tensioner front buckle

• Driver-side pre-tensioner front buckle short to power supply

• SAS control module internal malfunction

Diagnostic Procedure

STEP

INSPECTION

ACTION

1
Turn the ignition switch to the LOCK position.
Connect the WDS or the equivalent.
Turn the ignition switch to the ON position.
Using the WDS or equivalent, verify the DTCs and record the past malfunction DTCs.
Is the present malfunction DTC B1878 displayed?
Yes
Note
• Indicates a hard malfunction. The malfunction is still present. This malfunction cannot be cleared until it is corrected and the DTC is no longer displayed.
Go to the next step.
No
Intermittent malfunction. The malfunction is not present at this time. Go to Step 4.
2
Warning
• Handling the components improperly can accidentally deploy the air bags and pre-tensioner front buckle, which may seriously injure you. Read the service warnings and cautions before handling the SRS air bag system components.
(See SERVICE WARNINGS.)
(See SERVICE CAUTIONS.)
Turn the ignition switch to the LOCK position.
Refer to the air bag system deactivation procedure and deactivate the system.
Turn the ignition switch to the ON position.
Perform the DTC inspection.
Is DTC B1878 indicated?
Yes
Go to the next step.
No
Replace the driver-side pre-tensioner front buckle.
After replacement, go to Step 5.
3
Turn the ignition switch to the LOCK position.
Disconnect the negative battery cable.
Disconnect SAS control module connector.
Disconnect the SST (diagnostic simulator) from driver-side pre-tensioner front buckle connector.
Turn the ignition switch to the ON position.
Measure the resistance between SAS control module terminal 2V and 2Z, and between SAS control module terminal 2V and 2N.
Is the resistance less than 10,000 ohms?
Yes
Repair the related wiring harness. After repair, go to Step 5.
No
Replace the SAS control module.
After replacement, go to Step 5.
4
Refer to the past malfunction DTCs recorded during Step 1.
Are the past malfunction DTCs displayed during Step 1 intermittent malfunctions which are not displayed as present malfunction DTCs?
Yes
Inspect for an intermittent short to the power supply between the SAS control module and the driver-side pre-tensioner front buckle. Attempt to replicate the malfunction by flexing the wiring harness and cycling the ignition key between the ON and LOCK position repeatedly. Repair or replace if there is any intermittent malfunction.
After repair or replacement. go to the next step.
No
Go to the next step.
5
Refer to the past malfunction DTCs recorded during Step 1.
Was any past malfunction DTC displayed during Step 1?
Yes
If any DTC is displayed, refer to the DTC table, and repair the malfunctioning part according to the DTC inspection.
No
Refer to the reactivation procedure in the air bag system deactivation procedure, reactivate the system. Clear all DTCs.