How To Check Ecus

WARNING: This page is about a different variant/trim than selected.

Use the scan tool MB991958 and the SWS monitor kit to check ECUs.
The following ECUs can be checked by using the scan tool MB991958 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 ECU AND THEIR CONDITIONS

ECU 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 line are normal

ETACS-ECU

ETACS ECU

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

Front-ECU

FRONT ECU

OK⁽²⁾

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

Sunroof motor assembly (sunroof-ECU)

SUNROOF ECU

OK⁽²⁾

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

Other SWS-related ECUs

Other ECUs

ECUs are not used

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

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