DTC 64

Passenger's (Front) Air Bag Module (Squib) System Fault for Power Supply Circuit (Short-Circuited to Power Supply)

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.

DTC SET CONDITIONS
This DTC is set if there is a short to the power supply in the passenger's air bag module (squib) circuit.

TROUBLESHOOTING HINTS
- Damaged wiring harnesses or connectors
- Short to the power supply in the passenger's air bag module (squib) harness
- Malfunction of the SRS-ECU

DIAGNOSIS

Required Special Tools:
- MB9915O2: Scan Tool (MUT-II)
- MB991865: Dummy Resistor
- MB991866: Resistor Harness
- MB991223 (MB991222): Harness Set (Probe)

STEP 1. Check the passenger's air bag module.




1. Disconnect the passenger's air bag module connector C-12.




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 harness side connector by backprobing.
4. Connect the negative battery terminal.
5. Erase the DTC memory, and then recheck the DTC.

Q: Is DTC 64 set?

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

STEP 2. Check the passenger's air bag module circuit at the SRS-ECU connector C-137.




1. Disconnect the SRS-ECU connector C-137.

DANGER: To prevent the air bag from deploying unintentionally, disconnect the passenger's air bag module connector C-12 to short the squib circuit.




2. Disconnect the passenger's air bag module connector C-12.
3. Turn the ignition switch to the "ON" position.

CAUTION: Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened.




4. Measure the voltage between the C-137 harness side connector terminals 5, 6 and body ground. Voltage should be 0 volt.

Q: Is the measured voltage within the specified range?

YES: Erase the DTC memory, and recheck if any DTC sets. If DTC 64 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 power
supply between the SRS-ECU connector C-137 (terminal No.5 and 6) and the passenger's air bag module connector C-12 (terminal No.1 and 2).

Q: Are the harness wires between the SRS-ECU connector C-137 (terminal No.5 and 6) and the passenger's air bag module connector C-12 (terminal No.1 and 2) in good condition?

YES: Go to Step 4.
NO: Repair the harness wires between the SRS-ECU connector C-137 and the passengers air bag module connector C-12. Then go to Step 4.

STEP 4. Check the DTC.

Q: Is DTC 64 set?

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