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 CONDITIONS
- 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 with side-air bag is installed to the vehicles without side-air bag. However, the DTC is not set in the reverse case).
- If an open circuit occurs to the squib circuit, this DTC will be set.

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.

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." Scan Tool Connecting
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 (Refer to Controller Area Network, Diagnosis).

STEP 2. Recheck for diagnostic trouble code.

Check again if the DTC is set.

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

Q: Is the DTC set?

YES: If DTC B1BA5 is set, replace the SRS-ECU..

YES: If DTC code No.B1BA5 and other codes are set, perform the troubleshooting for the corresponding code.

NO: There is an intermittent malfunction such as poor engaged connector(s) or open circuit (Refer to general (Body and Chassis), How to Cope with Intermittent Malfunction).