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Home >> Mitsubishi >> 2006 >> Eclipse GS, Standard >> Repair and Diagnosis >> Restraints >> Restraints Control Systems >> Supplemental Restraint System >> SRS Air Bag Diagnosis >> Diagnostic Trouble Code Procedures >> DTC B1400: Driver's Air Bag Module (1st Squib) System Fault 1 (Short Circuit between Terminals of the Squib Circuit): DTC B1480: Driver's Air Bag Module (2nd Squib) System Fault 1 (Short Circuit between Terminals of the Squib Circuit) >> Diagnosis
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DTC B1400: Driver's Air Bag Module (1st Squib) System Fault 1 (Short Circuit between Terminals of the Squib Circuit): DTC B1480: Driver's Air Bag Module (2nd Squib) System Fault 1 (Short Circuit between Terminals of the Squib Circuit): Diagnosis

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 (MUT-III)  ."
    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 Scan Tool To Data Link Connector
    G04230562Courtesy 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 Use Troubleshooting/Inspection Service Points - HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ).

    Fig 2: Connecting Scan Tool To Data Link Connector
    G04230562Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  3. STEP 3. Using scan tool MB991958, read the diagnostic trouble code. 
    1. Turn the ignition switch to the "ON" position.
    2. Check if the DTC is set.
    3. Turn the ignition switch to the "LOCK" (OFF) position.

    Q: Is DTC B1519 set? 

    YES :  Go to Step 4.

    NO :  Go to  Step 5.

    Fig 3: Connecting Scan Tool To Data Link Connector
    G04230562Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  4. STEP 4. Check SRS-ECU connector C-123. 

    Q: Is the connector correctly engaged? 

    YES :  Go to Step 5.

    NO :  Engage the connector correctly. Then go to  Step 10.

    Fig 4: Disconnecting Connector C-123 Terminals
    G04237861Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  5. STEP 5. Check SRS-ECU connector C-123, clock spring connector C-307 and driver's air bag module connector C-305. (Using scan tool MB991958, read the diagnostic trouble code.) 
    1. Disconnect the negative battery terminal.
    2. Disconnect connectors C-123, C-307 and C-305, and then reconnect them.
    3. Connect the negative battery terminal.
    4. Erase the diagnostic trouble code memory, and check the diagnostic trouble code.

    Q: Is DTC B1400 < 1st squib > or B1480 < 2nd squib > set? 

    YES :  Go to Step 6.

    NO :  The procedure is complete. It is assumed that DTC B1400 < 1st squib > or B1480 < 2nd squib > set because connector C-123, C-307 or C-305 was engaged improperly.

    Fig 5: Disconnecting Connector C-123 Terminals
    G04237861Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    Fig 6: Identifying Clock Spring Connector C-307 And Driver's Air Bag Module Connector C-305
    G04237856Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  6. STEP 6. Check the driver's air bag module. (Using scan tool MB991958, read the diagnostic trouble code.) 
    1. Disconnect the negative battery terminal.
    2. Slide the outer housing of the clock spring side of driver's air bag module connector C-305 in the arrow direction shown in illustration, and disconnect the connector.
      Fig 7: Identifying Connector C-305 Terminals
      G04255882Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    3. Connect special tool MB991865 to special tool MB991866.
      CAUTION: Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened.
    4. Insert special tool MB991866 into clock spring side of driver's air bag module connector C-305 (terminal No. 1 and 2 < 1st squib > or No. 3 and 4 < 2nd squib >) by backprobing.
    5. Connect the negative battery terminal.
    6. Erase the diagnostic trouble code memory, and check the diagnostic trouble code.

    Q: Is DTC B1400 < 1st squib > or B1480 < 2nd squib > set? 

    YES :  Go to Step 7.

    NO :  Replace the driver's air bag module (Refer to AIR BAG MODULE(S) AND CLOCK SPRING  ). Then go to  Step 10.

    Fig 8: Connecting Special Tool MB991865 To Special Tool MB991866
    G04237858Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  7. STEP 7. Check the clock spring. (Using scan tool MB991958, read the diagnostic trouble code.) 
    1. Disconnect the negative battery terminal.
    2. Disconnect the clock spring connector C-307.
      Fig 9: Identifying Connector C-307 Terminals
      G04237859Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    3. Connect special tool MB991865 to special tool MB991866.
      CAUTION: Do not insert a test probe into the terminal from its front side directly, as the connector contact pressure may be weakened.
      Fig 10: Connecting Special Tool MB991865 To Special Tool MB991866
      G04237860Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    4. Insert special tool MB991866 into clock spring harness side connector C-307 (terminal No. 36 and 37 < 1st squib > or No. 34 and 35 < 2nd squib >) by backprobing.
    5. Connect the negative battery terminal.
    6. Erase the diagnostic trouble code memory, and check the diagnostic trouble code.

    Q: Is DTC B1400 < 1st squib > or B1480 < 2nd squib > set? 

    YES :  Go to Step 8.

    NO :  Replace the clock spring (Refer to AIR BAG MODULE(S) AND CLOCK SPRING  ). Then go to  Step 10.

  8. STEP 8. Check the driver's air bag module circuit. Measure the resistance at SRS-ECU connector C-123. 
    1. Disconnect SRS-ECU connector C-123.
      Fig 11: Disconnecting Connector C-123 Terminals
      G04237861Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
      WARNING: To prevent the air bag from deploying unintentionally, disconnect clock spring connector C-307 to short the squib circuit.
    2. Disconnect clock spring connector C-307.
      Fig 12: Identifying Connector C-307 Terminals
      G04237859Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
      CAUTION: Insert an insulator such as a cable tie to a depth of 4 mm (0.16 inch) or more, otherwise the short spring will not be released.
    3. Insert a cable tie [3 mm (0.12 inch) wide, 0.5 mm (0.02 inch) thick] between terminals 36, 37 < 1st squib > or 33, 34 < 2nd squib > and the short spring to release the short spring.
      Fig 13: Inserting Cable Tie Between Terminals 36, 37 And Short Spring (1st Squib)
      G04237863Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
      Fig 14: Inserting Cable Tie Between Terminals 33, 34 And Short Spring (2nd Squib)
      G04237864Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
      CAUTION: Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened.
    4. Check for continuity between C-123 harness side connector terminals 36 and 37 < 1st squib > or 33 and 34 < 2nd squib >. It should be open circuit.
      Fig 15: Checking Continuity Between C-123 Harness Side Connector Terminals 36 And 37 (1st Squib)
      G04237865Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Does continuity exist? 

    YES :  Erase the diagnostic trouble code memory, and check the diagnostic trouble code. If DTC B1400 < 1st squib > or B1480 < 2nd squib > set, replace the SRS-ECU (Refer to SRS CONTROL UNIT (SRS-ECU)  ). Then go to  Step 10.

    NO :  Go to Step 9.

    Fig 16: Checking Continuity Between C-123 Harness Side Connector Terminals 33 And 34 (2nd Squib)
    G04237866Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  9. STEP 9. Check the harness for short circuit between SRS-ECU connector C-123 (terminal No. 36 and 37 < 1st squib > or No. 33 and 34 < 2nd squib >) and clock spring connector C-307 (terminal No. 13 and 14 < 1st squib > or No. 11 and 12 < 2nd squib >). 

    Q: Are harness wires between SRS-ECU connector C-123 (terminal No. 36 and 37 < 1st squib > or No. 33 and 34 < 2nd squib >) and clock spring connector C-307 (terminal No. 13 and 14 < 1st squib > or No. 11 and 12 < 2nd squib >) in good condition? 

    YES :  Go to Step 10.

    NO :  Replace the harness wires between SRS-ECU connector C-123 and clock spring connector C-307. Then go to Step 10.

    Fig 17: Disconnecting Connector C-123 Terminals
    G04237861Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    Fig 18: Identifying Connector C-307 Terminals
    G04237859Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  10. STEP 10. 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 B1400 < 1st squib > or B1480 < 2nd squib > set? 

    YES :  Return to  Step 1.

    NO :  The procedure is complete.

    Fig 19: Connecting Scan Tool To Data Link Connector
    G04230562Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
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