DTC 72

Side-Airbag Module (RH) (Squib) System Fault 2 (Open in the Squib Circuit)

Side-Airbag Module (RH) (Squib) Circuit:

CIRCUIT OPERATION
- The SRS-ECU judges how severe a collision is by detecting signals from the left and right side impact sensors. If the impact is over a predetermined level, the SRS-ECU outputs an ignition signal. At this time, if the side-airbag safing G-sensor is on, the SRS air bag will inflate.
- The ignition signal is input to the air bag module to inflate the air bag.

DTC SET CONDITIONS
- These DTC are output if there is abnormal resistance between the input terminals of the side-airbag module (RH) (squib).

TROUBLESHOOTING HINTS
- Open circuit in the side-airbag module (RH) (squib) circuit
- Improper connector contact
- Malfunction of the SRS-ECU

DIAGNOSIS

Required Special Tools:
- MB991502: Scan Tool (MUT-II)
- MB991865: Dummy resister
- MB991866: Resister harness




STEP 1. Check the side-airbag module (RH).
1. 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.

2. Disconnect the side-airbag module (RH) connector D-27, and insert special tool MB991866 into the harness side connector by backprobing.
3. Connect the negative battery terminal.
4. Erase the DTC memory, and then recheck the DTC.

Q: Is DTC 72 output?

YES: Go to Step 2.
NO: Replace the seat back assembly of the front seat (RH). Refer to Front Seat. Then go to Step 4.







STEP 2. Check the harness for open circuit between SRS-ECU and the side-airbag module (RH).
1. Disconnect SRS-ECU connector C-13 and side-airbag module (RH) connector D-27, 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.




2. Check the continuity between the following terminals.

C-13 connector D-27 connector
23 2
24 1

- Should be less than 2 ohm.

Q: Is the continuity normal?

YES: Erase the DTC memory, and recheck if any DTC sets. If DTC 72 sets, replace the SRS-ECU. Then go to Step 4.
NO: Go to Step 3.







STEP 3. Check the harness wires for open circuit between SRS-ECU connector C-13 and side-airbag module (RH) connector D-27.

Q: Are the harness wires between SRS-ECU connector C-13 and side-airbag module (RH) connector D-27 in good condition?

YES: Go to Step 4.
NO: Repair the harness wires between SRS-ECU connector C-13 and side-airbag module (RH) connector D-27. Then go to Step 4.

STEP 4. Check for DTC.

Q: Is DTC 72 output?

YES: Return to Step 1.
NO: This diagnosis is complete. (If no malfunctions are not found in all steps an intermittent malfunction is suspected. Refer to How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction.)