Inspection Procedure 11: ASC does not operate or faulty ASC operate.
caution
If there is any problem in the CAN bus lines, an incorrect DTC 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.
COMMENTS ON TROUBLE SYMPTOM
When this trouble symptom occurs, the stability control/TCL system operation may be disabled. The stability control/TCL system may set the DTC.
TROUBLESHOOTING HINTS
Low battery output
Wiring harness or connector failure of CAN bus line
ASC-ECU malfunction
Engine coding data problem
DIAGNOSIS
STEP 1. Scan tool (M.U.T.-III) DTC
(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) Check the DTC for the ASC system.
Is the DTC set?
Carry out the diagnosis for the DTC (Refer to ).
Go to Step 2.
STEP 2. Engine ECU coding data check
Using scan tool (M.U.T.-III), check if any abnormality is present to the coding data below which are stored in the engine control module (Refer to GROUP 00 - Precautions before Service/Coding List ).
A.S.C.
OK: Available
Is the check result normal?
Go to Step 4.
Go to Step 3.
STEP 3. Engine ECU coding data check
Perform the variant coding to the ECM.
Is the check result normal?
Go to Step 5.
Replace the ECM (Refer to GROUP 13A - Engine Control Module <2.4L ENGINE>, GROUP 13B - Engine Control Module <3.0L ENGINE>). Then go to Step 5.
STEP 4. 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 ).
Is the check result normal?
Replace the hydraulic unit (integrated with ASC-ECU) (Refer to ). Then go to Step 5.
Connect the brake tubes correctly, and repair or replace the external brake lines of the hydraulic unit (integrated with ASC-ECU).
STEP 5. Operation check
Does stability control/TCL operate normally?
This diagnosis is complete.
Check the brake system related components other than the stability control/TCL system.