4: TCL Indicator Light Remains Illuminated After Engine Start

INSPECTION PROCEDURE 4: The TCL Indicator Light Remains Illuminated After the Engine is Started.





Part 1 of 2





Part 2 of 2

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 indicator light by turning the transistor in the ECU "ON" and "OFF."
^ The ABS-ECU illuminates the TCL indicator light on start-up. It turns off the light after 3 seconds when the ABS-ECU completes the self-check.

TECHNICAL DESCRIPTION (COMMENT)
The cause is probably the 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 the ABS-ECU connector A-03.
1. Disconnect ABS-ECU connector A-03.
2. Turn the ignition switch to the "ON" position.
Q: Does the TCL indicator 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 wires between ABS-ECU connector A-03 and combination meter connector C-29.

NOTE: After inspecting intermediate connector C-12, inspect the wire. If intermediate connector C-12 is damaged, repair or replace it. If the connector has been repaired, go to Step 3.

Q: Are any harness wires between ABS-ECU connector A-03 and combination meter connector C-29 damaged?
YES: Repair them and then go to Step 3.
NO: Go to Step 3.

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