DTC 72: Right Hand Side-Airbag 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
- MB991827: MUT-III USB Cable
- MB991911: MUT-III Main Harness B
MB991865: Dummy resister
MB991866: Resister harness

STEP 1. Check the side-airbag module (RH) (Using scan tool MB991958, read the diagnostic trouble code).
1. Disconnect the negative battery terminal.
2. 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 1: Connecting Special Tool MB991865 To Special Tool MB991866
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
3. Disconnect the side-airbag module (RH) connector D-19, and insert special tool MB991866 into the harness side connector by backprobing.
4. Connect the negative battery terminal.
5. Erase the DTC memory, and then recheck the DTC.
Q: Is DTC 72 set?
1. YES: Go to Step 2.
2. NO: Replace the seat back assembly of the front seat (RH). Refer to DISASSEMBLY AND ASSEMBLY . Then go to Step 3.
STEP 2. Check the harness for open circuit between SRS-ECU and the side-air bag module (RH).
1. Disconnect SRS-ECU connector C-74 and side-air bag module (RH) connector D-19, and measure at the wiring harness side.
  CAUTION: Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened.
  
  Fig 2: Identifying SRS-ECU Connector C-74
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  
  Fig 3: Identifying Side-Air Bag Module Connector D-19
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2. Check for continuity between the following terminals.
  - SRS-ECU connector C-74 (terminal No.23) and the side-air bag module (RH) connector D-19 (terminal No.2)
  - SRS-ECU connector C-74 (terminal No.24) and the side-air bag module (RH) connector D-19 (terminal No.1)
  - Should be less than 2 ohms.
  Fig 4: Checking Continuity Between SRS-ECU C-74 And Side-Air Bag Module D-19 Connector Terminal
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
Q: Does continuity exist?
1. YES: Erase the DTC memory, and recheck if any DTC sets. If DTC 72 sets, replace the SRS-ECU. Refer to HARNESS CONNECTOR . Then go to Step 3.
2. NO: Repair the harness wires between SRS-ECU connector C-74 and side-airbag module (RH) connector D-19. Then go to Step 3.
STEP 3. Recheck for diagnostic trouble code.
Q: Is DTC 72 set?
1. YES: Return to Step 1.
2. 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 MALFUNCTIONS ).