BYD Song Pro DM-I Auto Headlight Parts Assembly 7 Inch 48W

The BYD Song Pro DM-i (2022–2026) utilizes a specialized forward lighting architecture that integrates the "Dragon Face" design language with precision electronic control. This replacement module is developed to restore the original lighting performance across all variants, including the Champion and Intelligent Driving editions. By providing a 1:1 hardware match for OEM part numbers SA3J-4121010 (Left) and SA3J-4121020 (Right)—including the adaptive matrix "-A" variants—this component ensures the maintenance of factory-level front-fascia continuity without requiring structural modifications or wiring adjustments.

The electronic integration of this module is engineered to handshake directly with the Song Pro DM-i’s 12V electrical infrastructure and CAN-bus signaling network. This architecture allows for a standard plug-and-play installation, effectively preserving the native functionality of the "Dragon Beard" DRL animations and factory-calibrated lighting controls. Internally, the diode array is partitioned into an energy-efficient ~50W operational load, delivering a 6000K daylight-spectrum output that satisfies ECE R112 and CCC regulatory standards.

To ensure long-term reliability in diverse environmental conditions, the housing is molded from an ABS+PC composite substrate treated with a 3H UV-stabilized hard-coat to prevent surface degradation. The internal environment is protected by an IP67-rated hermetic seal, paired with an integrated pressure-balancing ventilation matrix to mitigate moisture cycles and prevent lens fogging. This configuration provides a stable and verified replacement path, ensuring the lighting output remains consistent with the original factory operational parameters throughout the vehicle’s service life.

Chassis-Matched Interface and CAN-Bus Protocol Alignment
The module is dimensionally and electrically configured to serve as a direct substitution for the BYD Song Pro DM-i (2022–2026). It employs original equipment mounting geometry, aligning with factory-spec intake points for both standard and adaptive matrix variants (SA3J-4121010/020). The internal circuitry is verified for signal compatibility with the vehicle’s native CAN-bus communication network, ensuring the module functions transparently within the existing diagnostic infrastructure, thereby preventing fault code generation or electronic handshake failures.

Solid-State Optical Engine
The lighting architecture utilizes a solid-state LED array that integrates DRL, low-beam, high-beam, and turn-signal functions within a unified assembly. This configuration replaces legacy lighting protocols to deliver instantaneous luminous flux upon circuit activation. The diode array is rated for a 50,000-hour service life, characterized by consistent operational stability and uniform light distribution, designed to minimize the need for mechanical adjustment or component replacement cycles.

Power Load Management and Spectral Compliance
The operational power envelope is calibrated to mirror factory specifications, with a 50W aggregate load (20W Low/High, 10W DRL). This power distribution is mapped to the hybrid energy management logic of the Song Pro DM-i, ensuring efficient draw without exceeding the vehicle's established electrical safety thresholds. The output is maintained at a 6000K color temperature, providing a spectral profile consistent with standard visibility benchmarks, with optical optics structured to regulate the horizontal cut-off line and minimize stray glare for oncoming traffic.

Atmospheric Ingress Protection
The assembly maintains an IP67 rating, providing a hermetic seal against both liquid and solid particulate intrusion. To manage thermal-related internal atmospheric changes, the unit incorporates a pressure-equalization ventilation matrix. This engineering feature is designed to neutralize internal pressure differentials during temperature-gradient shifts—such as those encountered during high-pressure cleaning or adverse weather exposure—effectively mitigating the risk of lens condensation.

Substrate Resilience and Optical Clarity
The housing is constructed from a reinforced ABS-PC composite substrate, selected for its balance of structural rigidity and vibration-dampening properties. The primary lens is composed of high-transmission Polycarbonate, treated with a 3H-rated UV-stabilized hard-coat. This protective layer is formulated to slow the rate of surface degradation, such as oxidation or yellowing, ensuring that the light-transmission efficiency remains within optimal operational ranges throughout the component's service lifespan.