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
















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 passenger’s air bag off indicator lamp connector D-09.

Q. Is the connector correctly engaged?
Go to Step 4.
Engage the connector correctly. Then go to Step 9.

STEP 4. Voltage measurement at passenger’s air bag off indicator lamp connector D-09.
(1)Disconnect the passenger’s air bag off indicator lamp connector D-09.
(2)Connect the negative battery terminal.
(3)Turn the ignition switch to the "ON" position.
(4)Measure the voltage between D-09 harness side connector terminal 1 and body earth.
OK: Approximately 12 volt

Q. Is the check result normal?
Go to Step 6.
Go to Step 5.

STEP 5. Check the harness for open circuit between ignition switch and passenger’s air bag off indicator lamp D-09 (terminal No.1).
note Prior to the wiring harness inspection, check junction block connector D-403, D-405 and repair if necessary.

Q. Is the check result normal?
Go to Step 6.
Repair the harness wires between ignition switch and the passenger’s air bag off indicator lamp connector D-09 (terminal No.1). Then go to Step 9.

STEP 6. Check SRS-ECU connector D-24.

Q. Is the connector correctly engaged?
Go to Step 7.
Engage the connector correctly. Then go to Step 9.

STEP 7. Check the harness for open circuit between the passenger’s air bag off indicator lamp connector D-09 (terminal No.3) and SRS-ECU connector D-24 (terminal No.21).

Q. Is the check result normal?
Go to Step 8.
Repair the harness wires between the passenger’s air bag off indicator lamp connector D-09 (terminal No.3) and SRS-ECU connector D-24 (terminal No.21). Then go to Step 9.

STEP 8. Check the passenger’s air bag off indicator lamp.
(1)Disconnect the negative battery terminal.
(2)Disconnected the SRS-ECU connector D-24, and measure at the wiring harness side.
(3)Connect the negative battery terminal.
(4)Turn the ignition switch to the "ON" position.
(5)
caution Do not insert a test probe into the terminal from its front side directly, as the connector contact pressure may be weakened.
Connect terminal No.21 to earth.

Q. Does the indicator lamp illuminate?
Erase the diagnosis code memory, and check the diagnosis code. If diagnosis code B1489 set, replace the SRS-ECU. (Refer to ). Go to Step 9.
Replace the passenger’s air bag off indicator lamp (Refer to GROUP 52A, Instrument Panel Assembly ). Go to Step 9.

STEP 9. 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.