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Home >> Mitsubishi >> 2014 >> Lancer SE >> Repair and Diagnosis >> External Pages >> Different car >> Section 37 (Supplemental Restraint System (SRS) - With Diagnostics) >> SRS Air Bag Diagnosis >> Diagnostic Trouble Code Procedures >> DTC B1C49: Seat belt pre-tensioner (passenger's side) (squib) system (open circuit of squib circuit) >> Diagnosis

DTC B1C49: Seat belt pre-tensioner (passenger's side) (squib) system (open circuit of squib circuit): Diagnosis

WARNING: This page is about a different car, the 2014 Mitsubishi Outlander. However, it is still accessible from the selected car via links, so may be relevant.
  1. STEP 1. Using scan tool (M.U.T.-III), diagnose the CAN bus line. 
    CAUTION: To 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).
    1. 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.

    Q: Is the CAN bus line found to be normal? 

    1. YES:  Go to Step 2.
    2. NO:  Repair the CAN bus line (Refer to DIAGNOSIS ).
  2. STEP 2. 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.

    Q: Is the DTC stored? 

    1. YES:  Go to Step 3.
    2. NO:  There is an intermittent malfunction such as poor engaged connector(s) or open circuit (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
  3. STEP 3. Diagnosis check by dummy resistor connection. 
    1. Check that the negative battery terminal is disconnected. If the negative battery terminal is connected, disconnect it.
    2. Use the flat-tipped screwdriver to pull out the locking button of harness side connector. After releasing the lock, disconnect the seat belt pre-tensioner (passenger's side) harness side connector.
      Fig 1: Pulling Out Locking Button Of Harness Connector
      G09666670Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    3. Connect special tool dummy resistor (MB991865) to special tool resistor harness (MB991884).
    4. Connect special tool resistor harness to the seat belt pre-tensioner (passenger's side) harness side connector.
    5. Connect the negative battery terminal.
    6. After erasing the DTC memory, check the DTC again.
    7. Disconnect the negative battery terminal.

    Q: Is DTC B1C49 stored? 

    1. YES:  Go to Step 4.
    2. NO:  Replace the seat belt with pre-tensioner (passenger's side) (Refer to SEAT BELTS WITH PRE-TENSIONER  ).
      Fig 2: Identifying Harness Side Connector And Special Tools
      G09666671Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  4. STEP 4. Resistance measurement at the SRS-ECU connector and the seat belt pre-tensioner (passenger's side) 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.
      WARNING: To release the SRS-ECU connector short spring in the following operations, disconnect this seat belt pre-tensioner connector, and keep the squib circuit shorted.
      Fig 3: Disconnecting SRS-ECU Connector
      G09666672Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    3. Use the flat-tipped screwdriver to pull out the locking button of harness side connector. After releasing the lock, disconnect the seat belt pre-tensioner (passenger's side) harness side connector.
      Fig 4: Pulling Out Locking Button Of Harness Connector
      G09666673Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
      CAUTION: The short spring may not be released due to the insufficient insertion. Therefore, insert the insulator for 4 mm (0.16 inch) or more.
    4. Insert an insulator [3 mm (0.12 inch) wide, 0.5 mm (0.02 inch) thick] such as cable tie between the PTA+, PTA- line, and the short spring, and release the short spring.
      Fig 5: Identifying Harness Side Connector And Cable Tie
      G09666674Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    5. Connect special tool resistor harness (MB991884) to the removed seat belt pre-tensioner (passenger's side) harness side connector.
      Fig 6: Identifying Harness Side Connector And Special Tools
      G09666675Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    6. Take the measurements below at the resistor harness and SRS-ECU harness side connector.
      • Continuity PTA+ line between SRS-ECU connector and resistor harness connector
      • Continuity PTA- line between SRS-ECU connector to resistor harness connector

        OK: Continuity (less than 2 Ω) 

    Q: Is the check result normal? 

    1. YES:  Go to Step 5.
    2. NO:  Repair the wiring harness PTA+, PTA- line between the SRS-ECU connector and the seat belt pre-tensioner (passenger's side) connector.
      Fig 7: Checking Continuity PTA+ Line Between SRS-ECU Connector And Resistor Harness Connector
      G09666676Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  5. STEP 5. 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.

    Q: Is DTC B1C49 stored? 

    1. YES:  Replace SRS-ECU (Refer to SRS-ECU  ).
    2. NO:  Intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
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