DTC 72

Side-Airbag Module (RH)(Squib) System Fault 2 (Open in the 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 side-airbag will inflate.
- The ignition signal is input to the side-airbag module to inflate the side-airbag.

DTC SET CONDITIONS
This DTC is set if an open circuit is detected between the terminals of the side-airbag module (RH) (squib). However, if the vehicle condition returns to normal, the SRS warning light will go out, but the DTC will be retained.

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 Resistor
- MB991866: Resistor Harness
- MB991223 (MB991222): Harness Set (Probe)

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

(1) Disconnect the side-airbag module (RH) connector D-24.

(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.

(3) Insert special tool MB991866 into the D-24 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?

YES: Go to Step 2.

NO: Replace the seatback assembly of the front seat (RH). (Refer to GROUP 23C, Front Seat Assembly) Then go to Step 3.










STEP 2. Check the harness wires for open circuit between the SRS-ECU connector C-145 (terminal No.23 and 24) and the side-airbag module (RH) connector D-24 (terminal No.1 and 2).

(1) Disconnect the SRS-ECU connector C-145 and the side-airbag module (RH) connector 0-24.

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.

C-145 connector D-24 connector

23 - 2

24 - 1

It should be less than 2 ohms.

Q: Does continuity exist?

YES: Erase the DTC memory, and recheck if any DTC sets. If DTC 72 sets, replace the SRS-ECU. Then go to Step 3.

NO: Repair the harness wires between the SRS-ECU connector C-145 and the side -airbag module (RH) connector D-24. Then go to Step 3.


STEP 3 Check for DTC.

Q: Is DTC 72 set?

YES: Return to Step 1.

NO: The procedure is complete. (If no malfunctions are not found in all steps, an intermittent function is suspected. Refer to INTRODUCTION, How to Use Troubleshooting/lnspection Service Points - How to Cope with Intermittent Malfunction)