DTC 62

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 air bag module (squib).

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

DIAGNOSIS

Required Special Tools:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: M.U.T.-III USB Cable
- MB991911: M.U.T.-III Main Harness B
- MB991865: Dummy resister
- MB991866: Resister harness

STEP 1. Check the driver's air bag module (Using scan tool MB991958, read the diagnostic trouble code).




1. Disconnect the negative battery terminal.
2. By sliding the A section (in the figure) of air bag module connector C-201 in arrow direction, disconnect the connector.




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 side air bag module connector C-201 by backprobing.
5. Connect the negative battery terminal.
6. Erase the diagnostic trouble code memory, and check the diagnostic trouble code.

Q: Is DTC 62 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 (Using scan tool MB991958, read the diagnostic trouble code).




1. Disconnect the clock spring connector C-205.
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 clock spring harness side connector C-205 (terminal No.3 and 4) by backprobing.
4. Connect the negative battery terminal.
5. Erase the diagnostic trouble code memory, and check the diagnostic trouble code.

Q: Is DTC 62 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-12.




1. Disconnect SRS-ECU connector C-12.

DANGER: To prevent the air bag from deploying unintentionally, disconnect the clock spring connector C-205 to short the squib circuit.




2. Disconnect the clock spring connector C-205.

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




3. Check for continuity between C-12 harness connector terminals 11, 12 and body ground. It should be open circuit.

Q: Does continuity exist?

YES: Go to Step 5.

NO: Erase the diagnostic trouble code memory, and check the diagnostic trouble code. If DTC 62 set, replace the SRS-ECU. Then go to Step 5.







STEP 4. Check the harness for short circuit to ground between SRS-ECU connector C-12 (terminal No.11 and 12) and clock spring connector C-205 (terminal No.3 and 4).

Q: Are the harness wires between SRS-ECU connector C-12 (terminal No.11 and 12) and clock spring connector C-205 (terminal No.3 and 4) in good condition?

YES: Go to Step 5.

NO: Repair the harness wires between SRS-ECU connector C-12 and clock spring connector C-205. Then go to Step 5.

STEP 5. Recheck for diagnostic trouble code.
Check again if the DTC is set.




1. Erase the DTC.
2. Turn the ignition switch to the "ON" position.
3. Check if the DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is DTC 62 set?

YES: Return to Step 1.

NO: The procedure is complete (If no malfunctions are found in all steps, an intermittent malfunction is suspected. Refer to How to Use Troubleshooting/INSPECTION Service Points - How to Cope with Intermittent Malfunction).