Code No.B1489: Air Bag Off Indicator Lamp does not Switch Off













caution If diagnosis code B1489 is set in the SRS-ECU, always diagnose the CAN main bus line.

OPERATION



  • Power for the passenger’s air bag off indicator lamp is supplied from the ignition switch (IG1).
  • The passenger’s air bag off indicator lamp illuminates when the ignition switch is turned to the "ON" position and goes out after approximately 7 seconds if there is not a malfunction in the SRS system.
  • When the passenger’s air bag cut off switch is turned "OFF", the lamp will stay on to show that the passenger from air bag is not operational.

DIAGNOSIS CODE SET CONDITIONS




PROBABLE CAUSES



  • Damaged wiring harnesses or connectors
  • Malfunction of the SRS-ECU
  • Malfunction of the passenger’s air bag off indicator lamp

DIAGNOSIS PROCEDURE


STEP 1. M.U.T.-III CAN bus diagnostics


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

Q. Is the check result normal?

Go to Step 2.
Repair the CAN bus lines (Refer to GROUP 54D, Diagnosis-Can Bus Diagnostic Chart ).

STEP 2. Check whether the diagnosis code is reset.


Check again if the diagnosis code is set.
(1)Erase the diagnosis code.
(2)Ignition: "LOCK" (OFF) position to "ON"
(3)On completion, check that the diagnosis code is not reset.

Q. Is the diagnosis code set?

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. Check the harness between SRS-ECU connector D-24 (terminal No.21) and the passenger’s air bag off indicator lamp connector D-09 (terminal No.3).



  • Check the passenger’s air bag off indicator lamp output lines for short circuit.

Q. Is the check result normal?

Go to Step 4.
Repair the harness wires. Then go to Step 5.

STEP 4. Check the passenger’s air bag off indicator lamp.


(1)Disconnect the negative battery terminal.
(2)Disconnected the SRS-ECU connector D-24.
(3)Connect the negative battery terminal.
(4)Turn the ignition switch to the "ON" position.

Q. Does the indicator lamp not illuminate?

Replace the passenger’s air bag off indicator lamp (Refer to GROUP 52A, Instrument Panel Assembly ). Go to Step 5.
Erase the diagnosis code memory, and check the diagnosis code. If diagnosis code B1489 set, replace the SRS-ECU. (Refer to ).

STEP 5. Check whether the diagnosis code is reset.


Check again if the diagnosis code is set.
(1)Erase the diagnosis code.
(2)Ignition: "LOCK" (OFF) position to "ON"
(3)On completion, check that the diagnosis code is not reset.

Q. Is the diagnosis code set?

Return to Step 1.
The procedure is complete.