Genuine OEM Mercedes-Benz Glow Plug Pre-Heat Relay, part number A6519008902. This control unit manages the pre-heating cycle for the glow plugs, ensuring reliable engine starting in cold conditions. It is a critical component of the ignition system. The relay weighs 0.088 kg. Genuine OEM relays are calibrated precisely to ensure correct timing and voltage for optimal glow plug performance and engine starting.