Inspection Procedure 4

INSPECTION PROCEDURE 4: The TCL warning light remains illuminated after the engine is started





NOTE: This diagnosis procedure is limited to cases where communication with the scan tool is possible (ABS-ECU power supply is normal) and no diagnostic trouble code outputs.





CIRCUIT OPERATION
- The ABS-ECU controls the illumination of the TCL warning light by turning it "ON" and "OFF."
- The ABS-ECU illuminates the TCL warning light on start-up. If turns the light off after 3 seconds when the ABS-ECU completes the self-check.

TECHNICAL DESCRIPTION (COMMENT)
The cause is probably hydraulic unit (integrated with ABS-ECU) malfunction.

TROUBLESHOOTING HINTS
- Damaged wiring harness
- Malfunction of the hydraulic unit (integrated with ABS-ECU)

DIAGNOSIS
Required Special Tool:
- MB991223: Harness Set





STEP 1. Check the power supply circuit at ABS-ECU connector A-02.
1. Disconnect ABS-ECU connector A-0G2.
2. Turn the ignition switch to the "ON" position.
Q: Does the TCL warning light illuminate?
YES: Go to Step 2.
NO: Replace the hydraulic unit (integrated with ABS-ECU) and then go to Step 3.








STEP 2. Check the harness wire between ABS-ECU connector A-02 and TCL warning light connector C-101.
Q: Are any harness wires between ABS-ECU connector A02 and TCL indicator light connector C-101 damaged?
YES: Repair them and then go to Step 3.
NO: Go to Step 3.

STEP 3. Check symptoms
Q: Does the TCL warning light turn off 3 seconds after start-up?
YES: This diagnosis is complete.
NO: Return to Step 1.