LEMON Manuals: Even more car manuals for everyone
Home >> Mitsubishi >> 2010 >> Lancer ES, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 6 (Supplemental Restraint System (SRS) -- Lancer Evolution) >> SRS Air Bag Diagnosis >> Diagnostic Trouble Code Procedures < SRS-Ecu > >> DTC B1B1B: Curtain Air Bag Module (LH) (Squib) System (Short Circuit Between Squib Circuit Terminals) >> Diagnosis

DTC B1B1B: Curtain Air Bag Module (LH) (Squib) System (Short Circuit Between Squib Circuit Terminals): Diagnosis

WARNING: This page is about a different car, the 2008 Mitsubishi Lancer. However, it is still accessible from the selected car via links, so may be relevant.

Required Special Tools: 

  1. STEP 1. Using scan tool MB991958, diagnose the CAN bus line. 
    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. 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.

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

    YES  : Go to Step 2.

    NO  : Repair the CAN bus line (Refer to DIAGNOSIS ).

    Fig 1: Connecting Special Tool MB991910 To Data Link Connector
    G05396268Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  2. STEP 2. Recheck for diagnostic trouble code. 

    Check again if the DTC is set.

    1. Erase the DTC.
    2. Turn the ignition switch to "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 3.

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

  3. STEP 3. Check SRS-ECU connector C-36, curtain air bag module (LH) connector F-28 and intermediate connector D-15. 
    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-36 SRS-ECU connector. Then connect the connector.
      Fig 2: Turning Lock Lever
      G05396269Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    3. After disconnecting the D-15 and F-28 harness side connectors, connect the connectors again. For the F-28 connector disconnection, use a flat-tipped screwdriver to unlock the locking button at the harness side connector by withdrawing it to ward you in two stages, and then disconnect the connector.
    4. After erasing the diagnostic trouble code memory, check the diagnostic trouble code again.
      Fig 3: Disconnecting Curtain Air Bag Module
      G05396270Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Is DTC B1B1B set? 

    YES  : Go to Step 4.

    NO  : Connector repair

  4. STEP 4. Check by dummy resistor connection. 
    1. Disconnect the negative battery terminal.
    2. Disconnect the D-15 intermediate connector (connection between curtain air bag harness and floor harness).
    3. Connect special tool MB991865 to special tool MB991866.
      CAUTION: Do not insert a probe into the terminal from its front side directly, as the connector contact pressure may be weakened.
    4. Insert the probe of resistor harness, to which the dummy resistor is installed, from the back of D-15 intermediate connector (floor harness side).
      Fig 4: Connecting Special Tool MB991865 To Special Tool MB991866
      G05396271Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    5. Connect the negative battery terminal.
    6. After erasing the diagnostic trouble code memory, check the diagnostic trouble code again.

    Q: Is DTC B1B1B set? 

    YES  : Go to Step 5.

    NO  : Go to  Step 6.

  5. STEP 5. Resistance measurement at the C-36 SRS-ECU connector. 
    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-36 SRS-ECU connector.
      Fig 5: Turning Lock Lever
      G05396272Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

      DANGER 

      To prevent the air bag from deploying unintentionally, disconnect the intermediate connector D-15 to short the squib circuit. 

    3. Disconnect the D-15 intermediate connector (connection between curtain air bag harness and floor harness).
      CAUTION: The short spring may not be released due to the insufficient insertion. Therefore, insert the insulator for 4 mm (0.6 inch) or more.
    4. Insert a cable tie [3 mm (0.12 inch) wide, 0.5 mm (0.02 inch) thick] between terminal 41, 42 and the short spring to release the short spring.
      Fig 6: Inserting Cable Tie Between Terminal 41, 42 And Short Spring
      G05396273Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    5. Check for continuity between the C-36 wiring harness side connector terminal No. 41 and No. 42.

      It should be open circuit.

    Q: Is it open circuit? 

    YES  : Go to  Step 7.

    NO  : Repair the wiring harness.

    Fig 7: Checking Continuity Between C-36 Wiring Side Connector Terminal No. 41 And No. 42
    G05396274Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  6. STEP 6. Short circuit check between the F-28 curtain air bag module harness side connector and the D-15 intermediate harness. 
    1. Disconnect the negative battery terminal.

      DANGER 

      To prevent the air bag from deploying unintentionally, disconnect the curtain air bag module connector F-28 to short the squib circuit. 

    2. Disconnect curtain air bag module (LH) F-28. Use a flat-tipped screwdriver to unlock the locking button at the harness side connector by withdrawing it toward you in two stages, and then disconnect the connector.
    3. Disconnect the D-15 intermediate connector (connection between curtain air bag harness and floor harness).
      Fig 8: Disconnecting Curtain Air Bag Module
      G05396275Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    4. Because the short spring is installed to the D-15 intermediate connector (curtain air bag harness side), insert a cable tie [3 mm (0.12 inch) wide, 0.5 mm (0.02 inch) thick] between terminals 1, 2 and the short spring to release the short spring.
      Fig 9: Inserting Cable Tie Between Terminals 1, 2 And Short Spring
      G05396276Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
      CAUTION: Do not insert a probe into the terminal from its front side directly, as the connector contact pressure may be weakened.
    5. Check for continuity between the D-15 intermediate connector (curtain air bag harness side) terminal No. 1 and 2.

      It should be open circuit.

      Fig 10: Checking Continuity Between D-15 Intermediate Connector Terminal No. 1 And 2
      G05396277Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Is it open circuit? 

    YES  : Replace the curtain air bag module (LH) (Refer to CURTAIN AIR BAG MODULE(S)  ). Then go to Step 7.

    NO  : Repair the wiring harness.

  7. STEP 7. 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 B1B1B set? 

    YES  : Replace SRS-ECU (Refer to SRS CONTROL UNIT (SRS-ECU)  ).

    NO  : Intermittent Malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).

scientia non olet · About LEMON Manuals