Inspection Procedure 10: Skid Control/TCL Does Not Operate: 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

1. STEP 1. Check the DTC. 

   Using scan tool, check the diagnostic trouble code for ASC system. (Refer to DIAGNOSTIC TROUBLE CODE CHART  .)

   Q: Is the check result normal? 

   1. YES:  Go to Step 2.
   2. NO:  Carry out the diagnosis for the DTC. (Refer to DIAGNOSTIC TROUBLE CODE CHART  .)
2. STEP 2. Engine control module coding data check 

   Using the scan tool, check if there is any abnormality to the following coding data stored in the engine control module. (Refer to CODING TABLE .)

   A.S.C. 

   OK: Present 

   Q: Is the check result normal? 

   1. YES:  Go to Step 3.
   2. NO:  Replace the engine control module. (Refer to ENGINE CONTROL MODULE .) Then go to Step  4.
3. 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 DIAGNOSTIC TROUBLE CODE CHART ).

   Q: Is the check result normal? 

   1. YES:  Replace the hydraulic unit (integrated with ASC-ECU). (Refer to HYDRAULIC UNIT CHECK  .) Then go to Step 4.
   2. NO:  Connect the brake tubes correctly, and repair or replace the external brake lines of the hydraulic unit (integrated with ASC-ECU).
4. STEP 4. Operation check 

   Q: Does the skid control/TCL operate normally? 

   1. YES:  The procedure is complete.
   2. NO:  Check the brake related components other than the skid control/TCL.