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DTC B1489: Passenger’s air bag OFF indicator light (open circuit)
 
 
cautionIf DTC B1489 is stored in the SRS-ECU, always diagnose the CAN main bus line.
 
 
CIRCUIT OPERATION
  • Power for the passenger’s air bag OFF indicator light is supplied from the ignition switch "ON" position.
  • The passenger’s air bag OFF indicator light illuminates when the ignition switch is turned to the "ON" position and goes out after approximately seven seconds if there is not a malfunction in the SRS system. In the following situations, the indicator will stay on to show that the passenger’s (front) air bag is not operational.
    • The front passenger’s seat is not occupied.
 
 
DTC SET CONDITIONS
This DTC will be stored if an open circuit has occurred in the wiring harness between the passenger’s air bag OFF indicator light and the SRS-ECU.
 
 
TROUBLESHOOTING HINTS
  • Damaged wiring harnesses or connectors
  • Malfunction of the SRS-ECU
  • Malfunction of the passenger’s air bag OFF indicator light
 
 
DIAGNOSIS
STEP 1. Using scan tool (M.U.T.-III), diagnose the CAN bus line.
(1)
cautionTo prevent damage to scan tool (M.U.T.-III), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-III).
Connect scan tool (M.U.T.-III). Refer to "How to connect the scan tool ."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is the CAN bus line found to be normal?
Go to Step 2.
Repair the CAN bus line (Refer to GROUP 54C, Diagnosis ).
 
STEP 2. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to the "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is the DTC 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 light.
It is checked whether the passenger’s air bag OFF indicator light is normal (Refer to ).
Is the check result normal?
Go to Step 4.
Replace passenger’s air bag OFF indicator light (Refer to ).
 
STEP 4. Resistance measurement at the SRS-ECU connector and the passenger’s air bag OFF indicator light 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 passenger’s air bag OFF indicator light connector.
(4) Take the measurements below at the SRS-ECU and passenger’s air bag OFF indicator light wiring harness side connectors.
  • Continuity 0FLP line between SRS-ECU connector and passenger’s air bag OFF indicator light connector
OK: Continuity (less than 2 Ω)
Is the check result normal?
Go to Step 5.
Repair the wiring harnesses 0FLP line between the SRS-ECU connector and the passenger’s air bag OFF indicator light connector.
 
STEP 5. Measure the voltage at the passenger’s air bag OFF indicator light connector.
(1) Disconnect the passenger’s air bag OFF indicator light connector.
(2) Connect the negative battery terminal.
(3) Ignition switch: ON
(4) Measure the voltage between the passenger’s air bag OFF indicator light harness side connector and the body ground.
OK: System voltage
Is the check result normal?
Go to Step 6.
Repair the wiring harness power supply line between the Ignition switch (IG1) and the passenger’s air bag OFF indicator light connector.
 
STEP 6. Recheck for diagnostic trouble code.
Check again if the DTC is stored.
(1) Erase the DTC.
(2) Turn the ignition switch to the "ON" position.
(3) Check if the DTC is stored.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is DTC B1489 stored?
Replace SRS-ECU (Refer to ).
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).