MERCEDES-BENZ

LI54.21-P-078926

2025-03-26 · NHTSA 11016046

A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.

Manufacturer summary

Original wording in English

Complaint Check engine light comes on when driving/starting the vehicle. No drivability concerns. Cause SW conflict of the 48V battery Remedy 1.-Check for SW in the 48V battery. 1. If SW is available, update the 48V battery. 2. Clear all faults and perform a few drive cycles. 3. If no faults return, the vehicle can be released. 2.-If no SW available, perform the following: - Charge the batteries (<5A charging current) - Erase the fault codes - Access the 12V battery contacts - Ignition off and bus sleep for 10 minutes - Disconnect the 12V battery - Wait 10 minutes - Disconnect Connector 3 at the 48V battery - Disconnect Connector 5 at the DCDC converter - Disconnect the 48V and 12V contacts (40/41 and 30/31) at the DCDC converter - Wait for 10 minutes - Reconnect everything back in opposite order and perform the ISU of the DCDC - Conduct a test drive and after check for fault codes U014687 and U044287

Repeated filings are grouped only when make, bulletin number, publication date and complete summary agree. Original record numbers are retained. Older publications remain available, and an explicit later version is shown when established. Pre-1994 vehicle associations are separated from default results; an unspecified year does not mean all model years apply.