DTC 65

Passenger's (Front) Air Bag Module (Squib) System Fault for Ground Circuit (Short-circuit to Ground)

Passenger's (Front) Air Bag Module (Squib) Circuit:

CIRCUIT OPERATION
- The SRS-ECU judges how severe a collision is by detecting signals from the front air bag analog G-sensor. If the impact is over a predetermined level, the SRS-ECU outputs an ignition signal. At this time, if the front air bag safing G-sensor is on, the SRS air bag will inflate.
- The ignition signal is input to the air bag module via the clock spring to inflate the air bag.

DTC SET CONDITIONS
- These DTC are output if there is abnormal resistance between the input terminals of the passenger's air bag module (squib). However, if no DTC resets, the SRS warning light will be switched off (DTC will be retained).

TROUBLESHOOTING HINTS
- Damaged harness wires and connectors
- Short to the ground in the passenger's air bag module (squib) harness
- Malfunction of the SRS-ECU

DIAGNOSIS

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







STEP 1. Check the passenger's air bag module.
1. Unclip passengers air bag module connector C-106.
2. Connect special toot 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. Disconnect the passenger's air bag module connector C-106, 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 65 output?

YES: Go to Step 2.
NO: Replace the front passenger's air bag module. Then go to Step 4.







STEP 2. Check the harness for short circuit to ground between the SRS-ECU and the passenger's air bag module.
1. Disconnect SRS-ECU connector C-12.
2. Unclip passenger's air bag module connector C-106.
3. Disconnect the passenger's air bag module connector C-106.
4. 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.




5. Check the continuity between terminals 9,10 and body ground.
- There should be open circuit.

Q: Is the continuity normal?

YES: Erase the DTC memory, and recheck if any DTC sets. If DTC 65 sets, replace the SRS-ECU. Then go to Step 4.
NO: Go to Step 3.







STEP 3. Check the harness wires for short circuit to ground between SRS-ECU connector C-12 and passenger's air bag module connector C-106.

Q: Are the harness wires between SRS-ECU connector C-12 and passenger's air bag module connector C-106 in good condition?

YES: Go to step 4.
NO: Repair the harness wires between SRS-ECU connector C-12 and passengers air bag module connector C-106. Then go to step 4.

STEP 4. Check the DTC.

Q: Is DTC 65 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.)