DTC B1489: Passenger's Air Bag OFF Indicator Light Drive Circuit System Fault 1 (Light does not Switch Off).: Diagnosis

Required Special Tools: 

• MB991958: Scan Tool (MUT-III Sub Assembly)
  • MB991824: Vehicle Communication Interface (V.C.I.)
  • MB991827: MUT-III USB Cable
  • MB991910: MUT-III Main Harness A (Vehicles with CAN communication)

1. STEP 1. 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.

   Q: Is the DTC set? 

   YES :  Go to  Step 2.

   NO :  There is an intermittent malfunction such as poor engaged connector(s) or open circuit (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).

   Fig 1: Connecting Scan To Data Link Connector

   Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2. STEP 2. Using scan tool MB991958, read the diagnostic trouble code. 
   CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
   1. Turn the ignition switch to the "ON" position.
   2. Check if the DTC is set.
   3. Turn the ignition switch to the "LOOK (OFF)" position.

   Q: Is DTC B1540, B1541, B1542, B1543, B1545 or B1546 set? 

   YES :  Carry out the troubleshooting of the occupant classification-ECU or the occupant classification sensor system (Refer to B1540 , B1541 , B1542 , or B1543 >, B1545 , or B1546 >).

   NO :  Go to  Step 3.

   Fig 2: Connecting Scan To Data Link Connector

   Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
3. STEP 3 Using scan tool MB991958, check actuator test. 
   • Item No.03: Passenger's air bag OFF indicator light illumination

   Q: Does the passenger's air bag indicator light illuminate or go out normally? 

   YES :  Go to  Step 4.

   NO :  Replace the passenger's air bag OFF indicator light (Refer to INSTRUMENT PANEL ASSEMBLY ). Then go to  Step 5.

4. STEP 4. Check the harness between SRS-ECU connector C-115 (terminal No.21) and passenger's air bag OFF indicator light C-121 (terminal No.3). 
   • Check the passenger's air bag OFF indicator light output lines for open circuit.

   Q: Is the check result satisfactory? 

   YES :  Erase the diagnostic trouble code memory, and check the diagnostic trouble code. If DTC B1489 sets, replace the SRS-ECU (Refer to SRS CONTROL UNIT (SRS-ECU) .) Then go to  Step 5.

   NO :  Repair the harness wires. Then go to  Step 5.

   Fig 3: Identifying Connector C-115 Terminals

   Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
   Fig 4: Checking Passenger's Air Bag OFF Indicator Light Connector C-121

   Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
5. STEP 5. 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.

   Q: Is DTC B1489 set? 

   YES :  Return to  Step 1.

   NO :  The procedure is complete.

   Fig 5: Connecting Scan To Data Link Connector

   Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.