Inspection Procedure 3

INSPECTION PROCEDURE 3:The SRS Warning Light does not Illuminate.

SRS Warning Light Circuit:

CIRCUIT OPERATION
- SRS-ECU sends the SRS warning light signal to the combination meter via the CAN communication.
- As a cause, the failure of CAN bus line, combination meter, or SRS-ECU is suspected.

TROUBLESHOOTING HINTS
- Damaged wiring harness and connectors
- Combination meter malfunction.
- Malfunction of SRS-ECU

DIAGNOSIS

Required Special Tools:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V.C.I.)
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A (Vehicles with CAN communication system)

STEP 1. Using scan tool MB991958, diagnose the CAN bus line.






CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or
disconnecting scan tool MB991958.

Use scan tool MB991958 to diagnose the CAN bus lines.

1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Diagnose the CAN bus line.

Q: Is the check result satisfactory?

YES : Replace the SRS-ECU.

NO : Repair the CAN bus line (Refer to Controller area network Diagnosis).