B1BA5

DTC B1BA5: SRS-ECU squib count mismatch

CAUTION:
If DTC B1BA5 is set in the SRS-ECU, always diagnose the CAN main bus line.

CIRCUIT OPERATION

SRS-ECU monitors the resistance value of each squib circuit on the vehicle. If any of the resistance values is outside the normal range, SRS-ECU sets the DTC.

DTC SET CONDITION

If an SRS-ECU different from the unit compatible to vehicle is accidentally installed, this DTC will be set (If SRS-ECU for the vehicles without side-airbag is installed to the vehicles with side-airbag. However, the DTC is not set in the reverse case).

TROUBLESHOOTING HINTS

- SRS-ECU incorrect installation
- Squib specification mismatch

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.





(1)
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.

Connect scan tool MB991958. Refer to "How to connect the scan tool Reading and Clearing Diagnostic Trouble Codes."
(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 CAN Bus Diagnostics Chart).

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. Is the DTC set?

YES Replace the SRS-ECU (Refer to Service and Repair).
NO There is an intermittent malfunction such as poor engaged connector(s) or open circuit How to Cope With Intermittent Malfunctions).