B1BC7

DTC B1BC7: SRS-ECU (Record Data Full) System

CAUTION: If the diagnostic trouble code B1BC7 is set to SRS-ECU, always diagnose the CAN main bus line.

CIRCUIT OPERATION
If SRS-ECU determines that a collision has occurred, it sends the ignition current to deploy the air bag. It stores the deployment status. If this DTC is set, SRS-ECU determines that the air bag has been deployed.

DTC SET CONDITIONS
This DTC is set after the air bag deployment. If this DTC is set before the air bag is deployed, an internal failure may have occurred in SRS-ECU.

TROUBLESHOOTING HINTS
Malfunction of SRS-ECU

DIAGNOSIS

Required Special Tools:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V.C.I.)
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A (Vehicles with CAN communication system)

STEP 1. Using scan tool MB991958, diagnose the CAN bus line.







CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

1. Connect scan tool MB991958. Refer to "How to connect the scan tool." How To Connect The Scan Tool (M.U.T.-III)
2. Turn the ignition switch to the "ON" position.
3. Diagnose the CAN bus line.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the CAN bus line found to be normal?

YES : Go to Step 2.

NO : Repair the CAN bus line.

STEP 2. Recheck for diagnostic trouble code.

Check again if the DTC is set.
1. Turn the ignition switch to the "ON" position.
2. Check if the DTC is set.
3. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Are any "Stored" or "Active" DTC B1BC7 set?

YES : Replace the SRS-ECU.

NO : There is an intermittent malfunction such as poor engaged connector(s) or open circuit.