How To Check Ecus

Use the scan tool MB991958 (M.U.T.-III Sub Assembly) and the SWS monitor kit to check ECUs.
The following ECUs can be checked by using the scan tool MB991958 (M.U.T.-III Sub Assembly) and the SWS monitor kit.
NOTE: The "ECU COMM Check" function checks the communication status of ECUs. "NG" does not always mean ECU malfunction. If a malfunction is found by the "ECU COMM Check," proceed to "Symptom Procedure" (Refer to SYMPTOM CHART ).

SWS monitor kit-compatible ECUs and their conditions

ECU CONDITION REFERENCE CHART

ITEM No.

ECUS TO BE CHECKED

DISPLAY ON SCAN TOOL

NORMAL CONDITION

ECU CONDITION

Column switch (column-ECU)

COLUMN ECU

OK⁽¹⁾

All of the column switch, power supply, ground and interconnecting communication lines are normal

ETACS-ECU

All of the ETACS-ECU switch, power supply, ground and interconnecting communication lines are normal

Front-ECU

FRONT ECU

OK⁽²⁾

All of the front-ECU, power supply, ground and interconnecting communication lines are normal

Sunroof-ECU

SUNROOF ECU

OK⁽²⁾

All of the sunroof motor assembly, power supply, ground and interconnecting communication lines are normal

⁽¹⁾	: If the ignition switch is turned to "LOCK" (OFF) or "ACC" when "NG" is displayed beside "ETACS ECU" or the signal request line is abnormal, the scan tool shows "NG" beside the "COLUMN ECU".

⁽²⁾	: When "NG" is displayed beside "ETACS ECU", the scan tool shows "NG" beside the "FRONT ECU" and "SUNROOF ECU".