DTC B1BA8: Occupant classification-ECU Out of Calibration/not Calibrated

caution

If DTC B1BA8 is set in the occupant classification-ECU, always diagnose the CAN main bus lines.

CIRCUIT OPERATION

The load data from the weight sensor is classified with the occupant classification-ECU, and its classified information is send to SRS-ECU by CAN bus line. The SRS-ECU determines the air bag deployment based on this classified information, and controls the power supply circuit to the inflator.

DTC SET CONDITION

This DTC is set when the 30 Kg (66 pounds) system and 0 Kg (0 pound) system have not been executed.

TROUBLESHOOTING HINTS

Zero calibration not executed
30 Kg (66 pounds) system and 0 Kg (0 pound) system not executed
Malfunction of the occupant classification-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

."
(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?

Go to Step 2.

Repair the CAN bus line (Refer to GROUP 54C, 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 B1BA7 set?

	After executing zero calibration of the occupant classification-ECU, execute 30 Kg (66 pounds) system and 0 Kg (0 pound) system. Then go to Step 3.

	There is an intermittent malfunction such as poor engaged connector(s) or open circuit (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).

STEP 3. Recheck for diagnostic trouble code.

Check again if the DTC is set to the occupant classification-ECU.

(1)Erase the DTC.

(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.

(3)Check if DTC is set.

(4)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is the DTC set?

	Replace the front seat cushion frame (RH) (Refer to GROUP 52A, Front Seat Assembly ) <Except RALLIART> or replace the slide adjuster (RH) (Refer to GROUP 52A, Front Seat Assembly ) <RALLIART>.

	There is an intermittent malfunction such as poor engaged connector(s) or open circuit (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).