Inspection Procedure 1: Scan Tool Communication Only With ABS/TCL/Skid Control System Is Impossible

Inspection Procedure 1: Scan tool Communication only with ABS/TCL/Skid Control system is Impossible.

CAUTION:
^ If there is any problem in the CAN bus lines, an incorrect diagnosis code may be set. Prior to this diagnosis, diagnose the CAN bus lines.
^ Whenever ECU is replaced, ensure that the CAN bus lines are normal.
^ When the hydraulic unit (integrated with ASC-ECU) is replaced, always carry out the calibration of the steering wheel sensor, the G and yaw rate sensor and brake fluid pressure sensor.

COMMENTS ON TROUBLE SYMPTOM
When scan tool cannot communicate with the ABS/TCL/ASC system, the CAN bus line, ASC-ECU power supply circuit system, or ASC-ECU may be faulty.

PROBABLE CAUSES
^ Damaged wiring harness and connectors
^ ASC-ECU malfunction
^ Wrong routing of scan tool harness
^ Abnormality in battery or alternator
^ Abnormality in power supply voltage to ASC-ECU
^ ECU malfunction of other system

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

STEP 1. M.U.T.-III CAN bus diagnostics
Use scan tool to diagnose the CAN bus lines.
Q: Is the check result normal?
YES: Check the power supply circuit, and repair if necessary.
NO: Repair the CAN bus lines.