DTC 62

Driver's Air Bag Module (Squib) System Fault For Ground Circuit (Short-Circuited To Ground)

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 input 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 side air bag module (squib). However, if no DTC resets, 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 ground in the driver's air bag module (squib) harness
- Malfunction of the SRS-ECU

Required Special Tools:
- MB991502: Scan Tool (MUT-II)
- MB991613: SRS Check Harness
- MB991865: Dummy resistor
- 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-81. special tool MB991613 to special tool MB991866.
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 recheck the DTC.

Q: Is DTC 22 out put?

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 the clock spring connector C-85.




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 clock spring harness side connector C-85 (terminal No.3 and 4) by backprobing.
5. Connect the negative battery terminal.
6. Erase the DTC memory, and then recheck the DTC.

Q: Is DTC 62 output?

YES: Go to Step 3.

NO: Replace the clock spring. Then go to Step 5.

STEP 3. Check the harness for short circuit to ground between the SRS-ECU and the clock spring.










1. Disconnect SRS-ECU connector C-72.
2. Disconnect the clock spring connector C-85.
3. 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.

4. Check the continuity between terminals 7, 8 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 62 sets, replace the SRS-ECU. Then go to Step 5.

NO: Go to Step 4.







STEP 4. Check the harness for short circuit to ground between SRS-ECU connector C-72 (terminal No.7 and 8) and clock spring connector C-85 (terminal No.3 and 4).

Q: Are the harness wires between SRS-ECU connector C-72 (terminal No.7 and 8) and clock spring connector C-85 (terminal No.3 and 4) in good condition?

YES: Go to Step 5.

NO: Repair the harness wires between SRS-ECU connector C-72 and clock spring connector C-85. Then go to Step 5.

STEP 5. Check the DTC.

Q: Is DTC 62 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.)