DTC 79

Side-Airbag Module (LH) (Squib) System Fault 5 for Power Supply Circuit

Side Impact Sensor (LH) 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.

DTC SET CONDITIONS
- These DTC are output if communication between the side impact sensor (LH) and the SRS-ECU is not possible or communication is faulty.

TROUBLESHOOTING HINTS
- Damaged wiring harnesses or connectors
- Malfunction of the side impact sensor (LH)
- Malfunction of the SRS-ECU

DIAGNOSIS

Required Special Tool:
- MB991502: Scan Tool (MUT-II)

STEP 1. Check the side impact sensor (LH).
1. Replace the side impact sensor (LH) with the side impact sensor (RH).
2. Connect the negative battery terminal.
3. Erase DTC memory, and then recheck the DTC.

Q: Is DTC 89 or 96 output?

YES: Replace the side impact sensor (LH) with a new one. Then go to Step 3.
NO: Go to Step 2.










STEP 2. Check the harness wires for open circuit or short circuit between SRS-ECU connector C-13 and side impact sensor (LH) connector D-17.

NOTE: After inspecting intermediate connector C-128 inspect the wiring harness. If the intermediate connector C-128 is damaged, repair or replace it. Refer to Harness Connector Inspection. Then go to Step 3. If harness wires are in good condition, go to Step 3. If any harness wires between SRS-ECU connector C-13 and side impact sensor (LH) connector D-17 are damaged, repair them or install the sensor cable. Then go to Step 3.

Q: Are the harness wires between SRS-ECU connector C-13 and side impact sensor (LH) connector D-17 in good condition?

YES: Erase the DTC memory, and recheck if any DTC sets. If DTC 79 or 93 sets, replace the SRS-ECU. Then go to Step 3.
NO: Repair the harness wires between SRS-ECU connector C-13 and side impact sensor (LH) connector D-17. Then go to Step 3.

STEP 3. Check for DTC.

Q: Is DTC 79 or 93 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.)