Inspection Procedure 1

Inspection Procedure 1: Cannot communicate with KOS-ECU using the scan tool.









TROUBLESHOOTING HINTS
- Damaged wiring harness and connectors.
- Malfunction of KOS-ECU.

DIAGNOSIS

MB991958: Scan Tool (M.U.T.-III Sub Assembly)
MB991824: Vehicles Communication Interface (V.C.I.)
MB991827: M.U.T.-III USB Cable
MB991910: M.U.T.-III Main Harness A (Vehicles with CAN communication system)

STEP 1. V.C.I. status check.
Check that the V.C.I. indicator light is illuminated in green.

Q: Is it illuminated in green?

YES : Diagnose the CAN bus line, and repair if necessary.

NO : Go to Step 2.

STEP 2. Check ETACS-ECU connector C-301 and data link connector C-125 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is the ETACS-ECU connector C-301 and data link connector C-125 in good condition?

YES : Go to Step 3.

NO : Repair the defective connector.

STEP 3. Check the wiring harness between the ETACS-ECU connector C-301 (terminal No.4, 5) and the data link connector C-125 (terminal No. 14,6).
Check the power supply line for open circuit.

Q: Is the wiring harness between ETACS-ECU connector C-301 (terminal No.4, 5) and the data link connector C-125 (terminal No. 14, 6) in good condition?

YES : Go to Step 4.

NO : The wiring harness may be damaged or the connector (s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary.

STEP 4. Check the wiring harness between the data link connector C-125 (terminal No.4, 5) and the ground.
Check the ground wires for open circuit.

Q: Is the wiring harness between data link connector C-125 (terminal No.4, 5) and the ground in good condition?

YES : Check the scan tool (M.U.T.-III). (Refer to M.U.T.-III User's Manual).

NO : Repair the wiring harness.