CODE NO. B1BB3 Passenger’s air bag cut off switch circuit (earth side) shorted
CODE NO. B1BB4 Passenger’s air bag cut off switch circuit (power supply side) shorted
CODE NO. B1BB5 Passenger’s air bag cut off switch circuit open




caution If the diagnosis code B1BB3, B1BB4 or B1BB5 is set to SRS-ECU, be sure to diagnose the CAN bus line.

OPERATION


According to the passenger’s air bag cut off switch connecting position, the SRS-ECU judges the deployment and non-deployment of passenger’s (front) air bag.

DIAGNOSIS CODE SET CONDITIONS


Diagnosis code is set when the resistance between input terminals of the passenger’s air bag cut off switch is without the standard value.
Cause of trouble in each diagnosis code is as follows.
Code No.
 Symptom
B1BB3
 Short to body earth in the common terminal harness
B1BB4
 Short to the power supply in the common terminal harness
B1BB5
 Malfunction of the common terminal or open circuit in its harness

PROBABLE CAUSES





DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics.
Use M.U.T.-III to diagnose the CAN bus lines.

Q. Is the check result normal?
Go to Step 2.
Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting ).

STEP 2. Check whether the diagnosis code is reset.
(1)Connect the negative battery terminal.
(2)After erasing the diagnosis code memory, check the diagnosis code again.
(3)Disconnect the negative battery terminal.

Q. Is the diagnosis code No.B1BB3, B1BB4 or B1BB5 set?
Go to Step 3.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).

STEP 3. Connector check: D-13 passenger’s air bag cut off switch connector

Q. Is the check result normal?
Go to Step 4.
Repair the defective connector.

STEP 4. Check the passenger’s air bag cut off switch.
Check of a passenger’s air bag cut off switch (Refer to ).

Q. Is the check result normal?
Go to Step 5.
Replace passenger’s air bag cut off switch (Refer to ).

STEP 5. Check the passenger’s air bag cut off switch circuit. Resistance measurement at SRS-ECU connector D-32.
(1)Disconnect the negative battery terminal.
(2)Disconnect SRS-ECU connector D-32.
(3)Switch the passenger’s air bag cut off switch to air bag ON side.
(4)Measure the resistance between terminal 19 and terminal 20.
OK: No Continuity
(5)Switch the passenger’s air bag cut off switch to air bag OFF side.
(6)Measure the resistance between terminal 19 and terminal 20.
OK: Continuity (less than 2 Ω)

Q. Is the check result normal?
Go to Step 6.
Repair the harness wires between SRS-ECU connector D-32 (terminal No.19 and 20) and passenger’s air bag cut off switch connector C-13 (terminal No.4 and 1).

STEP 6. Check whether the diagnosis code is reset.

Q. Is diagnosis code No.B1BB3, B1BB4 or B1BB5 set?
Replace the SRS-ECU (Refer to ).
An intermittent malfunction is suspected (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).