DTC 61
Driver's Air Bag Module (Squib) System Fault for Power Supply Circuit (Short-Circuited to Power Supply)Driver's 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 sent to the air bag module via the clock spring to inflate the air bag.
DTC SET CONDITIONS
This DTC is set if there is abnormal resistance between the input terminals of the driver's air bag module (squib). However, if no DTC is reset, the SRS warning light will be switched off (DTC will be retained).
TROUBLESHOOTING HINTS
- Malfunction of the clock spring
- Damaged harness wires and connectors
- Short to the power supply in the driver's air bag module (squib) harness
- Malfunction of the SRS-ECU
DIAGNOSIS
Required Special Tools:
- MB991502: Scan Tool (MUT-II)
- MB991613: SRS check harness
- MB991865: Dummy resister
- MB991866: Resister harness
STEP 1. Check the driver's air bag module.
1. Disconnect the negative battery terminal.
2. Remove the driver's air bag module.
3. Connect connector (4) of special tool MB991613 to clock spring connector C-63.
4. Connect connector 1.of special tool MB991613 to connector (2).
5. Connect terminals 22 to 24, and terminals 23 to 25 of special tool MB991613 to connector (5).
6. Connect the clock spring to the body wiring harness.
7. Connect the negative battery terminal.
8. Erase the DTC memory, and then check for the diagnostic trouble code.
Q: Is DTC 61 set?
YES: Go to Step 2.
NO: Replace the driver's air bag module. Then go to Step 5.
STEP 2. Check the clock spring.
1. Disconnect the negative battery terminal.
2. Disconnect clock spring connector C-62.
3. 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.
4. Insert special tool MB991866 into C-62 clock spring harness connector (terminals 3 and 4) by backprobing.
5. Connect the negative battery terminal.
6. Erase the DTC memory, and then check for the diagnostic trouble code.
Q: Is DTC 61 set?
YES: Go to Step 3.
NO: Replace the clock spring. Then go to Step 5.
STEP 3. Check the driver's air bag module circuit at the SRS-ECU connector C-44.
1. Disconnect SRS-ECU connector C-44.
DANGER: To prevent the air bag from deploying unintentionally, disconnect clock spring connector C-62 to short the squib circuit.
2. Disconnect clock spring connector C-62.
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 C-44 harness connector terminals 7, 8 and body ground. Voltage should measure 0 volt.
Q: Is the measured voltage within the specified range?
YES: Erase the DTC memory, and check for the diagnostic trouble code. If DTC 61 is set, replace the SRS-ECU. Then go to Step 5.
NO: Go to Step 4.
STEP 4. Check the harness for short circuit to power supply between SRS-ECU connector C-44 (terminals 7 and 8) and clock spring connector C-62 (terminals 3 and 4).
Q: Are harness wires between SRS-ECU connector C-44 (terminals 7 and 8) and clock spring connector C-62 (terminals 3 and 4) in good condition?
YES: Go to Step 5.
NO: Repair the harness wires between SRS-ECU connector C-44 and clock spring connector C-62. Then go to Step 5.
STEP 5. Check for the diagnostic trouble code.
Q: Is DTC 61 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 How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction).