DTC 62: Driver's Air Bag Module (Squib) System Fault for Ground Circuit (Short-Circuited to Ground): Diagnosis
Required Special Tools:
- MB991502: Scan Tool (MUT-II)
- MB991613: SRS Check Harness
- MB991865: Dummy Resistor
- MB991866: Resistor Harness
- MB991223 (MB991222): Harness Set (Probe)
- STEP 1. Check the SRS-ECU to clock spring line.
- Disconnect the negative battery terminal.
- Disconnect the clock spring connector C-204 (4-pin).
- 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.
- Insert special tool MB991866 into the clock spring harness side connector C-204 (terminal No.3 and 4) by backprobing.
- Connect the negative battery terminal.
- Erase the DTC memory, and then recheck the DTC.
Q: Is DTC 62 set?
YES : Go to Step 3.
NO: Go to Step 2.
- STEP 2. Check the clock spring and the driver's air bag module.
- Disconnect the negative battery terminal.
- Connect connector (4) of special tool MB991613 to clock spring connector C-208.
- Connect connector (1) of special tool MB991613 to connector (2).
- Connect terminals 22 to 24, and terminals 23 to 25 of special tool MB991613 to connector (5).
- Connect the clock spring to the instrument panel wiring harness.
- Connect the negative battery terminal.
- Erase the DTC memory, and then recheck the DTC.
Q: Is DTC 62 set?
YES : Replace the clock spring (Refer to AIR BAG MODULES AND CLOCK SPRING ). Then go to Step 4.
NO: Replace the driver's air bag module (Refer to AIR BAG MODULES AND CLOCK SPRING ). Then go to Step 4.
- STEP 3. Check the driver's air bag module circuit at the SRS-ECU connector C-137.
- Disconnect the SRS-ECU connector C-137.
WARNING: To prevent the air bag from deploying unintentionally, disconnect the clock spring connector C-204 to short the squib circuit.
- Disconnect the clock spring connector C-204.
CAUTION: Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened.
- Check for continuity between the C-137 harness side connector terminals 7, 8 and body ground.
It should be open circuit.
Q: Does continuity exist?
YES : Go to Step 5.
NO: Erase the DTC memory, and recheck if any DTC sets. If DTC 62 sets, replace the SRS-ECU. (Refer to SRS CONTROL UNIT (SRS-ECU) ). Then go to Step 5.
- Disconnect the SRS-ECU connector C-137.
- STEP 4. Check the harness wires for short circuit to ground between the SRS-ECU connector C-137 (terminal No.7 and 8) and the clock spring connector C-204 (terminal No.3 and 4).
Q: Are the harness wires between the SRS-ECU connector C-137 (terminal No.7 and 8) and the clock spring connector C-204 (terminal No.3 and 4) in good condition?
YES : Go to Step 5.
NO: Repair the harness wires between the SRS-ECU connector C-137 and the clock spring connector C-204. Then go to Step 5.
- STEP 5. Check the DTC.
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 TO COPE WITH INTERMITTENT MALFUNCTION ).