DIAGNOSIS
TSB Revision
ACTIVE STABILITY CONTROL SYSTEM (ASC)
35C-257
PROBABLE CAUSES
• Low battery output
• Wiring harness or connector failure of CAN bus line
• ASC-ECU malfunction
• Different ETACS-ECU, abnormal variant coding information
• Abnormal engine coding data
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
STEP 1. Check the DTC.
Using scan tool, check the diagnostic trouble code for ASC sys-
tem. (Refer to
P.35C-22
.)
Q: Is the check result normal?
YES : Go to Step 2.
NO : Carry out the diagnosis for the DTC. (Refer to
P.35C-22
.)
STEP 2. Engine control module coding data check
Using the scan tool, check if there is any abnormality to the fol-
lowing coding data stored in the engine control module. (Refer
to GROUP 00 − Coding Table
P.00-26
.)
A.S.C.
OK: Present
Q: Is the check result normal?
YES : Go to Step 3.
NO : Replace the engine control module. (Refer to GROUP
13A − Engine Control Module
P.13A-888
.) Then go to
Step 4.
STEP 3. Hydraulic unit (integrated with ASC-ECU) check
Check that the brake tube is correctly mounted to the hydraulic
unit (integrated with ASC-ECU). (Refer to
P.54A-646
.)
Q: Is the check result normal?
YES : Replace the hydraulic unit (incorporates in
ASC-ECU).(Refer to
P.35C-284
.) Then go to Step 4.
NO : Connect the brake tubes correctly, and repair or
replace the external brake lines of the hydraulic unit
(integrated with ASC-ECU).
STEP 4. Operation check
Q: Does the skid control/TCL operate normally?
YES : The procedure is complete.
NO : Check the brake related components other than the
skid control/TCL.