DTC B1B02: Driver's Air Bag Module (1st squib) System (Squib Circuit Open); DTC B1B06: Driver's Air Bag Module (2nd squib) System (Squib Circuit Open): Diagnosis

Required Special Tools:

MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V.C.I.)
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A (Vehicles with CAN Communication System)
MB991865: Dummy resistor
MB991866: Resister harness

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
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
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.
  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 ).
STEP 3. Check the driver's air bag module.
1. Disconnect the negative battery terminal.
2. Slide the outer housing of the driver' s air bag module connector C-207 in the arrow direction shown in illustration, and disconnect the connector.
  
  Fig 2: Identifying Driver' S Air Bag Module Connector
  Courtesy 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-207 (terminal No. 1 and 2 <1st squib> or terminal No. 3 and 4 < 2nd squib >) by backprobing.
5. Connect the negative battery terminal.
  
  Fig 3: Inserting Special Tool MB991866 Into Clock Spring Side Air Bag Module Connector C-207
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  
  CAUTION: Always DTC B1B06 is set when checking DTC B1B02. This is because the second side terminal is isolated when checking it. DTC B1B06 is set but this is not a fault. In addition, always DTC B1B02 is set when checking DTC B1B06 because the first side terminal is isolated.
6. Erase the diagnostic trouble code memory, and check the diagnostic trouble code.
  Q: Is the checked DTC set?
  
  YES: Go to Step 4.
  
  NO: Replace the driver's air bag module (Refer to DRIVER'S AIR BAG MODULE AND CLOCK SPRING <EXCEPT FOR RALLIART> ), (Refer to DRIVER'S AIR BAG MODULE AND CLOCK SPRING < RALLIART > ). Then go to Step 6.
STEP 4. Check the clock spring.
1. Disconnect the negative battery terminal.
2. Disconnect the clock spring connector C-208.
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 special tool MB991866 into harness side of clock spring connector C-208 (terminal No. 3 and 4 <1st squib> or terminal No. 1 and 2 < 2nd squib >) by backprobing.
5. Connect the negative battery terminal.
  
  Fig 4: Inserting Special Tool MB991866 Into Clock Spring Harness Side Connector C-208
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  
  CAUTION: Always DTC B1B06 is set when checking DTC B1B02. This is because the second side terminal is isolated when checking it. DTC B1B06 is set but this is not a fault. In addition, always DTC B1B02 is set when checking DTC B1B06 because the first side terminal is isolated.
6. Erase the diagnostic trouble code memory, and check the diagnostic trouble code.
  Q: Is the checked DTC set?
  
  YES: Go to Step 5.
  
  NO: Replace the clock spring (Refer to DRIVER'S AIR BAG MODULE AND CLOCK SPRING <EXCEPT FOR RALLIART> ), (Refer to DRIVER'S AIR BAG MODULE AND CLOCK SPRING < RALLIART > ). Then go to Step 6.
STEP 5. Check the harness between the SRS-ECU connector C-122 (terminal No. 5 and 6 <1st squib> or terminal No. 9 and 10 < 2nd squib >) and the clock spring connector C-208 (terminal No. 4 and 3 < 1st squib > or terminal No. 1 and 2 < 2nd squib >) for open circuit.
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-122 SRS-ECU connector.
3. Disconnect the clock spring connector C-208.
  
  Fig 5: Identifying Lock Lever
  Courtesy 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.
4. Insert a cable tie [3 mm (0.12 inch) wide, 0.5 mm (0.02 inch) thick] between terminals 5, 6 <1st squib> or 9, 10 < 2nd squib > and the short spring to release the short spring.
  
  Fig 6: Inserting Cable Tie Between Terminals 5 And 6
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  
  Fig 7: Inserting Cable Tie Between Terminals 9 And 10
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  
  CAUTION: Do not insert a probe into the terminal from C-208 harness side connector front side directly, as the connector contact pressure may be weakened.
5. Check for continuity between the following terminals. It should be less than 2 ohms.
  - SRS-ECU connector C-122 (terminal No. 5) and the clock spring connector C-208 (terminal No. 4) <1st squib>
  - SRS-ECU connector C-122 (terminal No. 6) and the clock spring connector C-208 (terminal No. 3) <1st squib>
    
    Fig 8: Checking Continuity Between SRS-ECU Connector C-122 Terminal No. 5 And Clock Spring Connector C-208 Terminal No. 4
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  - SRS-ECU connector C-122 (terminal No. 9) and the clock spring connector C-208 (terminal No. 1) <2nd squib>
  - SRS-ECU connector C-122 (terminal No. 10) and the clock spring connector C-208 (terminal No. 2) <2nd squib>
    Q: Does continuity exist?
    
    YES: Erase the diagnostic trouble code memory, and check the diagnostic trouble code. If DTC B1B02 <1st squib> or B1B06 < 2nd squib > set, replace the SRS-ECU (Refer to SRS CONTROL UNIT (SRS-ECU) ). Then go to Step 6.
    
    NO: Replace the harness wires between SRS-ECU connector C-122 and clock spring connector C-208. Then go to Step 6.
    
    Fig 9: Checking Continuity Between SRS-ECU Connector C-122 Terminal No. 10 And Clock Spring Connector C-208 Terminal No. 2
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
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.
  Q: Is DTC B1B02 <1st squib> or B1B06 < 2nd squib > set?
  
  YES: Return to Step 1.
  
  NO: The procedure is complete.