[Previous][Next]
DTC B1489: Passenger’s Air Bag OFF Indicator Light (Open Circuit)
 
 

cautionIf DTC B1206 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 fusible link (34).
  • 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 occupant is determined to be less than 66 lbs (30 kg) by the occupant classification-ECU.
    • The front passenger’s seat is not occupied.
 
 
DTC SET CONDITIONS
This DTC will be set 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 MB991958, diagnose the CAN bus line.
(1)
cautionTo prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
Connect scan tool MB991958. 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.
(1) 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 center panel assembly (Refer to GROUP 52A - Instrument Panel Assembly ).
 
STEP 4. Check the harness for open circuit between SRS-ECU connector C-126 (terminal No.13) and the center panel assembly connector C-205 (terminal No.14).
(1) Disconnect the negative battery terminal.
(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 C-126 SRS-ECU connector.
(3) Disconnect the center panel assembly connector C-205.
(4) Check for continuity between the following terminals. It should be less than 2 ohms.
  • SRS-ECU connector C-126 (terminal No.13) and the center panel assembly connector C-205 (terminal No.14)
Does continuity exist?
Go to Step 5.
Repair the harness wires.
 
STEP 5. Measure the voltage at the center panel assembly connector.
(1) Disconnect the negative battery terminal.
(2) Disconnect the C-205 center panel assembly connector.
(3) Connect the negative battery terminal.
(4) Ignition switch: ON.
(5) Measure the voltage between the C-205 harness side connector terminal No. 12 and body ground.
  • The voltage should measure approximately 12 volts (battery positive voltage).
Is the measured voltage approximately 12 volts (battery positive voltage)?
Go to Step 6.
Repair the wiring harness between the C-417 ETACS-ECU connector terminal No. 5 and the C-205 instrument center panel assembly connector terminal No. 12.
 
STEP 6. 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 DTC B1489 set?
Replace SRS-ECU (Refer to ).
There is an intermittent malfunction such as poor engaged connector(s) or open circuit (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).