Code No. B1488 Passenger’s air bag OFF indicator lamp (short circuited)


caution If the diagnosis code B1488 is set in the SRS-ECU, be sure to diagnose the CAN bus line

OPERATION



  • Power for the passenger’s air bag OFF indicator lamp is supplied from the fusible link (2).
  • The passenger’s air bag OFF indicator lamp illuminates when the ignition switch is turned to the "ON" position and goes out after approximately 6 to 8 seconds if there is not a malfunction in the SRS system.

TROUBLE JUDGEMENT



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 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. B1488 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. Check the passenger’s air bag OFF indicator lamp.
It is checked whether passenger’s air bag OFF indicator lamp is normal (Refer to ).

Q. Is the check result normal?
Go to Step 4.
Replace hazard indicator assembly (Refer to GROUP 52A - Instrument Panel Assembly ).

STEP 4. Resistance measurement at the SRS-ECU connector.
(1)Check that the negative battery terminal is disconnected. If the negative battery terminal is connected, disconnect it.

(2)While pushing the part "A" indicated in the figure of the harness side connector, turn the lock lever to the direction of the arrow to release the lock lever, and disconnect the SRS-ECU connector.
(3)Disconnect the hazard indicator assembly connector.
(4)Take the measurements below at the SRS-ECU connector.

  • Continuity between OFLP line and body earth
OK: No continuity

Q. Is the check result normal?

Go to Step 5.

Repair the wiring harnesses OFLP line between the SRS-ECU connector and the hazard indicator assembly connector.

STEP 5. Resistance measurement at the hazard indicator assembly connector.
(1)Check that the negative battery terminal is disconnected. If the negative battery terminal is connected, disconnect it.

(2)While pushing the part "A" indicated in the figure of the harness side connector, turn the lock lever to the direction of the arrow to release the lock lever, and disconnect the SRS-ECU connector.
(3)
caution Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened.
Take the following measurements at the backside of the hazard indicator assembly side connector (harness side).

  • Continuity between LP line and body earth
OK: No continuity

Q. Is the check result normal?

Go to Step 6

Repair the wiring harnesses LP line between the hazard indicator assembly connector and the body earth.

STEP 6. Check whether the diagnosis code is reset.

Q. Is the diagnosis code No. B1488 set?
Replace SRS-ECU (Refer to ).
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).