Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

How to Check ECUs

HOW TO CHECK ECUs
1. Use the scan tool MB991958 and the SWS monitor kit to check ECUs.




2. The given 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".

NOTE:
- *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".