Car rear section - LOGO - Light - Component function
The "LOGO lights" at the rear of the car are not legal safety lights but rather a brand identification lighting component. Their main function is to enhance the brand recognition and visual sense of ceremony at night. Some models also have decorative interlocking functions, but they do not participate in the transmission of safety signals such as braking, steering, or reversing.
Core functional positioning:
Brand identification: Lights up the vehicle's brand logo (such as "BYD" or "ZEEKER" lettering) at night or in low-light conditions to strengthen the vehicle's identity recognition.
Aesthetic decoration: Combined with greeting/dismissal light languages and atmosphere linkage, it creates a sense of technology and luxury, and is a non-mandatory standard configuration.
Non-safety signals: Do not have braking, steering, reversing, or outline legal warning functions and cannot replace any safety lights.
Common components and forms:
Integrated LED markers: LED light beads are embedded inside the LOGO, and they are activated by the door opening light or a separate switch (such as some models of BYD's Dragon series).
Projection/illuminative markers: Light the brand's shadow through a lens or a light guiding structure, or form a dynamic breathing effect with the tail lights (such as in some models of ZEEKER and Audi's new energy vehicles).
Control logic： Usually managed by the vehicle body control module (BCM)， and can be set to always on， activated with the main lights， or customized light language modes. Notes for Attention
Regulatory Compliance: The light color must comply with the regulations (usually white or the brand color), and red constant illumination is strictly prohibited to avoid confusion with the brake light signal.
Function Boundary: If the vehicle only turns on the LOGO light but not the outline light, it is still a violation during night driving as it cannot indicate the width of the vehicle's outline.
Problems with the rear LOGO light of the car usually manifest as not lighting up, constant illumination that does not go out, or abnormal flashing. The main causes are concentrated on switch jamming, line short circuit/fault connection, control module misjudgment or setting not being turned off. It is necessary to first distinguish whether it is "design constant illumination" or "true fault".
Core Troubleshooting and Resolution Steps
Confirm if it is a normal design: Some models (such as Zeke, Lincoln, etc.) support a brief illumination of the rear logo light after locking the car (about 10 seconds) or the ability to set a constant greeting effect. Refer to the lighting settings menu in the "Owner's Manual" to confirm that it is not mistakenly activated.
Check the brake pedal return and switch: If the LOGO light remains constantly illuminated after the car is turned off and locked, 90% of the time it is due to the jamming of the brake light micro-switch or the contact sticking, causing the circuit to remain continuously conductive; try pressing the brake pedal multiple times to see if it rebounds, or temporarily disconnect the switch to test if the light goes out.
Check the lines and fuses: Check if the LOGO light connector is oxidized and loose, or if the wire harness insulation layer is damaged and short-circuited; if accompanied by other electrical abnormalities or a dead battery, measure the voltage and check if the corresponding fuse is blown.
Reset the system and professional diagnosis: Disconnect the negative terminal of the battery for 5 minutes to clear temporary fault codes; if ineffective, use an OBD diagnostic tool to read the fault codes of the vehicle body control module (BCM), to determine if it is a control program bug or module damage.
Common Fault Phenomena Comparison
After locking the car, the light remains constantly illuminated: It is mostly due to brake switch failure, parking light mode misactivation, or line short circuit. This can lead to battery depletion over time.
During driving, the light does not light up/flashes: It may be due to light bulb damage, poor contact of the light socket, mismatch in CAN bus encoding (especially after modifying with LED), or sensor false alarm.
The dashboard reports a fault but the light is normal: It is mostly due to critical filament breakage, poor grounding, or ECU self-check misjudgment. It is necessary to clean the connector or install a decoding resistor.
If involving disassembling the rear door trim panel, replacing the switch, or programming matching, it is recommended to handle it at an authorized service center to avoid damaging the waterproof seal or triggering more electronic faults.
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