DTC 79
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 and the analog G-sensor. If the impact is over a predetermined level, the SRS-ECU outputs an ignition signal. At this time, if the 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
1. Replace the side impact sensor (LH) with the side impact sensor (RH).
2. Connect the negative battery terminal.
3. Erase DTC memory.
Q: Is DTC 79 or 93 erased or 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 between SRS-ECU connector C-45 and side impact sensor (LH) connector D-20.
NOTE: After inspecting intermediate connector D-23, inspect the wiring harness. If the intermediate connector D-23 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-45 and side impact sensor (LH) connector D-20 are damaged, repair them or install the sensor cable. Then go to Step 3.
Q: Are the harness wires between SRS-ECU connector C-45 and side impact sensor (LH) connector D-20 in good condition?
YES: Go to Step 3.
NO: Repair them. Then go to Step 3.
STEP 3. Check for DTC.
Q: Is any of DTC 79 or 93 output?
YES: Replace the SRS-ECU.
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.)