DTC 22: Driver's Air Bag Module (Squib) System Fault 2 (Open in the Squib Circuit): Diagnosis

Required Special Tools: 

• MB991958: Scan Tool (MUT-III Sub Assembly)
  • MB991824: Vehicle Communication Interface (V.C.I.)
  • MB991827: MUT-III USB Cable
  • MB991911: MUT-III Main Harness B (Vehicles without CAN communication system)
• MB991865: Dummy resister
• MB991866: Resister harness

1. STEP 1. Check the driver's air bag module (Using scan tool MB991958, read the diagnostic trouble code). 
   1. Disconnect the negative battery terminal.
   2. By sliding the A section (in the figure) of air bag module connector C-201 in the arrow direction, disconnect the connector.
      Fig 1: Identifying Air Bag Module Harness Connector C-201

      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 air bag module connector C-201 by backprobing.
   5. Connect the negative battery terminal.
   6. Erase the diagnosis trouble code memory, and check the diagnosis trouble code.
      Fig 2: Inserting Special Tool MB991866 Into Clock Spring Side Air Bag Module Connector C-201

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

   Q: Is DTC 22 set? 

   • YES:  Go to Step 2.
   • NO:  Replace the driver's air bag module (Refer to AIR BAG MODULES AND CLOCK SPRING  .) Then go to  Step 4.
2. STEP 2. 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-205.
   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 harness side connector C-205 by backprobing.
   5. Connect the negative battery terminal.
   6. Erase the diagnostic trouble code memory, and check the diagnostic trouble code.

   Q: Is DTC 22 set? 

   • YES:  Go to Step 3.
   • NO:  Replace the clock spring (Refer to AIR BAG MODULES AND CLOCK SPRING  .) Then go to  Step 4.
     Fig 3: Inserting Special Tool MB991866 Into Clock Spring Harness Side Connector C-205

     Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
3. STEP 3. Check the harness between the SRS-ECU connector C-12 (terminal No.11 and 12) and the clock spring connector C-205 (terminal No.3 and 4) for open circuit. 
   1. Disconnect SRS-ECU connector C-12 and clock spring connector C-205.
      Fig 4: Identifying SRS-ECU Connector C-12

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
      Fig 5: Identifying Clock Spring Connector C-205

      Courtesy 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.
   2. Check for continuity between the following terminals.
      • SRS-ECU connector C-12 (terminal No.11) and the clock spring connector C-205 (terminal No.3)
      • SRS-ECU connector C-12 (terminal No. 12) and the clock spring connector C-205 (terminal No.4)

      It should be less than 2 ohms.

      Q: Does continuity exist? 

   • YES:  Erase the diagnostic trouble code memory, and check the diagnostic trouble code. If DTC 22 sets, replace the SRS-ECU (Refer to SRS CONTROL UNIT (SRS-ECU)  .) Then go to Step 4.
   • NO:  Repair the harness wires between SRS-ECU connector C-12 and clock spring connector C-205. Then go to Step 4.
     Fig 6: Checking Continuity Between Terminals Connector C-12 And C-205

     Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
4. STEP 4. Recheck for diagnostic trouble code. 

   Q: Is DTC 22 set? 

   • YES:  Return to  Step 1.
   • NO:  The procedure is complete (If no malfunctions are found in all steps, an intermittent malfunction is suspected. Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION .)