DTC 65: Passenger's (Front) Air Bag Module (Squib) System Fault for Ground Circuit (Short-Circuited to Ground): Diagnosis
Required Special Tools:
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V.C.I.)
- MB991827: MUT-III USB Cable
- MB991911: MUT-III Main Harness B (Vehicles without CAN communication system)
- MB991865: Dummy resister
- MB991866: Resister harness
- STEP 1. Check the passenger's air bag module (Using scan tool MB991958, read the diagnostic trouble code).
- Disconnect the negative battery terminal.
- Unclip passenger's air bag module connector C-106.
- 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.
- Disconnect the passenger's air bag module connector C-106, and insert special tool MB991866 into the harness connector by backprobing.
- Connect the negative battery terminal.
- Erase the diagnostic trouble code memory, and check the diagnostic trouble code.
Q: Is DTC 65 set?
- YES: Go to Step 2.
- NO: Replace the passenger's air bag module (Refer to AIR BAG MODULES AND CLOCK SPRING .) Then go to Step 4.
- STEP 2. Check the passenger's air bag module circuit at the SRS-ECU connector C-12.
- Disconnect SRS-ECU connector C-12.
DANGER
To prevents the air bag from deploying unintentionally, disconnect the passenger's air bag module connector C-106 to short the squib circuit.
- Unclip passenger's air bag module connector C-106.
- Disconnect the passenger's air bag module connector C-106.
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 C-12 harness connector terminals 9, 10 and body ground.
It should be open circuit.
Q: Does continuity exist?
- YES: Go to Step 3.
- NO: Erase the diagnostic trouble code memory, and check the diagnostic trouble code. If DTC 65 sets, replace the SRS-ECU (Refer to SRS CONTROL UNIT (SRS-ECU) .) Then go to Step 4.
- Disconnect SRS-ECU connector C-12.
- STEP 3. Check the harness wires for short circuit to ground between SRS-ECU connector C-12 (terminal No.9 and 10) and passenger's air bag module connector C-106 (terminal No.1 and 2.)
Q: Are the harness wires between SRS-ECU connector C-12 (terminal No.9 and 10) and passenger's air bag module connector C-106 (terminal No.1 and 2) in good condition?
- YES: Go to Step 4.
- NO: Repair the harness wires between SRS-ECU connector C-12 and passenger's air bag module connector C-106. Then go to Step 4.
- STEP 4. Recheck for diagnostic trouble code.
Q: Is DTC 65 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 COPE WITH INTERMITTENT MALFUNCTION .)