2018 Mercedes-Benz GLC 300 electrical system problems

13 owner complaints filed with NHTSA name the electrical system on the 2018 Mercedes-Benz GLC 300 — 15% of all complaints for this model year.

Electrical System complaints

15%

share of all complaints

—

median reported incident mileage

2 / 0

crash / fire reports

What owners report

“Safety Issue: Infotainment display screen produces scrambled pixels during Apple CarPlay navigation while driving. Description: When Apple CarPlay is connected and navigation is in use, the vehicle's infotainment display screen suddenly produces scrambled pixels, rendering the map and display…”
filed Apr 21, 2026
“I had the engine light come on and took it to the dealership. They quoted me over 8 thousand dollars to fix. I took it to a repair shop that works on luxury cars and they fixed it for less than 1000 dollars. I had to have the transducer fixed in the turbo in my engine and when they did that they…”
filed Nov 6, 2025

Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.

Complaint Service code B1 displayed in the customer menu does not match the workshop code displayed in the workshop menu, e.g., 505 or 550A, which includes a service A. Cause The root cause is currently being…
LI00.20-P-080703 · Service Bulletin/Repair Instructions · issued Jun 12, 2026
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
Complaint The customer requests deactivation of the N112/9 HERMES communication module Note: Deactivation of the HERMES control unit (N112/9) is not supported for gray-market vehicles. Cause Before deactivating the…
LI82.85-P-080559 · Service Bulletin/Repair Instructions · issued May 26, 2026