Inspection Procedure 1: Scan tool (M.U.T.-III) communication with ABS/ASC system is impossible.
caution
If there is any problem in the CAN bus lines, an incorrect diagnostic trouble code may be set. Prior to this diagnosis, diagnose the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ).
Whenever ECU is replaced, ensure that the CAN bus lines are normal.
If the power is supplied with the ground circuit of CAN communication device open circuited, an electric potential abnormality may occur to the CAN bus lines.
COMMENTS ON TROUBLE SYMPTOM
When scan tool cannot communicate with the ABS/ASC system, the CAN bus lines, ASC-ECU power supply circuit system, ground, or ASC-ECU may be faulty.
TROUBLESHOOTING HINTS
Damaged wiring harness and connectors
ASC-ECU malfunction
Wrong routing of scan tool (M.U.T.-III) harness
Abnormality in battery or generator
Abnormality in power supply voltage to ASC-ECU
ECU malfunction of other system
Scan tool (M.U.T.-III) CAN bus diagnostics
(1)
caution
To prevent damage to scan tool (M.U.T.-III), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-III).
Connect scan tool (M.U.T.-III). Refer to "How to connect the Scan Tool (M.U.T.-III) ."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is the check result normal?
Check the power supply circuit, and repair if necessary (Refer to ).
Repair the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ).