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DTC B1488: Passenger's air bag OFF indicator light (short circuited)
 
 
cautionIf DTC B1488 is set 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 electric motor switch ON position.
  • The passenger’s air bag OFF indicator light illuminates when the electric motor 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 set if the passenger’s air bag OFF indicator light driving circuit is short to ground. If the vehicle condition returns to normal, DTC B1488 will be automatically erased, and the warning light will go out.
 
 
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.-IIISE), diagnose the CAN bus line.
(1)
cautionTo prevent damage to scan tool (M.U.T.-IIISE), always turn off the power supply mode of the electric motor switch before connecting or disconnecting scan tool (M.U.T.-IIISE).
Connect scan tool (M.U.T.-IIISE). Refer to "How to connect the scan tool ."
(2) Turn on the power supply mode of the electric motor switch.
(3) Diagnose the CAN bus line.
(4) Turn off the power supply mode of the electric motor switch.
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 DTC.
Check again if the DTC is set.
(1) Erase the DTC.
(2) Turn on the power supply mode of the electric motor switch.
(3) Check if the DTC is set.
(4) Turn off the power supply mode of the electric motor switch.
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 interior indicator (Refer to GROUP 54A, Interior Light ).
 
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 interior indicator connector.
(4) Take the measurements below at the SRS-ECU connector.
  • Continuity between 0FLP line and body ground
OK: No continuity
Is the check result normal?
Go to Step 5.
Repair the wiring harnesses 0FLP line between the SRS-ECU connector and the interior indicator connector.
 
STEP 5. Recheck for DTC.
Check again if the DTC is set.
(1) Erase the DTC.
(2) Turn on the power supply mode of the electric motor switch.
(3) Check if the DTC is set.
(4) Turn off the power supply mode of the electric motor switch.
Is the DTC 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 ).