CODE NO. B1489 Passenger’s air bag OFF indicator lamp (open circuit)
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If diagnosis code B1489 is set in the SRS-ECU, be sure to diagnose the CAN bus line
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OPERATION
- Power for the passenger’s air bag OFF indicator lamp is supplied from the Ignition switch (IG1) <Vehicles without KOS> or the IG1 relay <Vehicles with KOS>.
- 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
This code will be set if an open circuit has occurred in the wiring harness between the passenger’s air bag OFF indicator lamp and the SRS-ECU.
PROBABLE CAUSES
- Damaged wiring harnesses or connectors
- Malfunction of the SRS-ECU
- Malfunction of the passenger’s air bag OFF indicator lamp
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STEP 1. M.U.T.-III CAN bus diagnostics.
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Use M.U.T.-III to diagnose the CAN bus lines.
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Q.
Is the check result normal?
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 Go to Step 2.
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 Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting  ).
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STEP 2. Check whether the diagnosis code is set again.
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(1)Connect the negative battery terminal.
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(2)After erasing the diagnosis code memory, check the diagnosis code again.
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(3)Disconnect the negative battery terminal.
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Q.
Is diagnosis code No. B1489 set?
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Go to Step 3.
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Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).
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STEP 3. Check the passenger’s air bag OFF indicator lamp.
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It is checked whether passenger’s air bag OFF indicator lamp is normal (Refer to ).
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Q.
Is the check result normal?
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Go to Step 4.
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Replace hazard indicator assembly (Refer to GROUP 52A, Instrument Centre Panel ).
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STEP 4. Resistance measurement at the SRS-ECU connector and the passenger’s air bag OFF indicator lamp connector.
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(1)Check that the negative battery terminal is disconnected. If the negative battery terminal is connected, disconnect it.
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(2)Disconnect the SRS-ECU connector.
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(3)Disconnect the passenger’s air bag OFF indicator lamp connector.
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(4)Take the measurements below at the SRS-ECU and passenger’s air bag OFF indicator lamp wiring harness side connectors.
- Continuity 0FLP line between SRS-ECU connector and passenger’s air bag OFF indicator lamp connector
OK: Continuity (less than 2 Ω)
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Q.
Is the check result normal?
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Go to Step 5.
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Repair the wiring harnesses 0FLP line between the SRS-ECU connector and the hazard indicator assembly connector.
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STEP 5. Measure the voltage at the passenger’s air bag OFF indicator lamp connector.
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(1)Disconnect the passenger’s air bag OFF indicator lamp connector.
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(2)Connect the negative battery terminal.
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(4)Measure the voltage between the hazard indicator assembly harness side connector and the body earth.
OK: System voltage
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Q.
Is the check result normal?
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Go to Step 6.
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Repair the wiring harness power supply line between the Ignition switch (IG1) <Vehicles without KOS> or IG1 relay <Vehicles with KOS> and the hazard indicator assembly.
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STEP 6. Check whether the diagnosis code is set again.
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Q.
Is diagnosis code No. B1489 set?
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Replace SRS-ECU (Refer to ).
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Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).
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