2007 Mercedes-Benz S550 electrical system problems
11 owner complaints filed with NHTSA name the electrical system on the 2007 Mercedes-Benz S550 — 20% of all complaints for this model year.
What owners report
“I went to replace my low beam and high beam bulbs on the passenger side and found that the wiring for the low beam had 0 insulation on it and I installed the new high beam bulb and the wires starting arcing causing the car to turn off the high beams and start smoking from the headlight assembly.”
filed Sep 24, 2024
“Struts and braking system have been unstable since I purchased the car. Wiring harness leaks oil and caused ecu to intermintinli turn off and on. Also the heat control timing caused car to over heat . Eventually I replaced the ecu 2 years ago at dealer . Mercedes has parts that are not safe to be…”
filed Oct 29, 2022
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Related service bulletins
Complaint After successful commissioning of the HERMES control unit (N112/9) with XENTRY Diagnosis DVD 03/2026, the message "SOS - service not activated" appears on the instrument cluster. In addition, the following two…
LI82.85-P-080507 · Service Bulletin/Repair Instructions · issued May 26, 2026
Electrical System problems in other S550 years
| Year | Reports | Share |
|---|---|---|
| 2015 S550 | 5 | 12% |
| 2014 S550 | 1 | 4% |
| 2008 S550 | 4 | 21% |
Other reported problem areas on the 2007 Mercedes-Benz S550
Counts are unique NHTSA complaints naming this component group. Complaints are unverified owner reports; mileage is computed only from complaints that included a usable odometer reading.