What is the reason for the BYD S7 brake light staying on?

[EllieRose]

Possible causes for the BYD S7 brake light staying on: 1. Lack of brake fluid: Brake fluid plays a crucial role in the vehicle's braking system. When the driver presses the brake pedal, the force applied is transmitted by the piston in the master cylinder through the brake fluid to the individual wheel cylinders, causing the brake pads to contact the wheels and stop the vehicle. A lack of brake fluid is often accompanied by noticeably reduced braking power and, in severe cases, a complete loss of braking. This issue can be resolved by promptly replenishing the brake fluid. 2. Faulty brake switch: This usually occurs when there is poor contact between the brake pedal and the brake sensor switch or if the sensor switch is damaged. Inspection and possible replacement are necessary. 3. Worn or aged brake pads: Worn or aged brake pads can also cause the brake light to stay on. In this case, the thickness of the brake pads should be checked. If the thickness is below the specified value (generally 0.8 cm), there is a risk of the pads cracking during driving, which could be dangerous.

[DelLaila]

I own a BYD S7 and have encountered the issue of the brake lights staying on several times. The most common cause is a faulty brake pedal switch underneath. The brake switch on BYD S7 tends to wear out or develop poor contact—when you press and release the pedal, it might not spring back to position, continuously sending signals to keep the lights illuminated. Another possibility could be a wiring short circuit, where moisture from rainy weather corrodes wires and causes shorts, or a blown fuse while the lights remain on. More complex cases might involve control module failures, such as a malfunctioning BCM (Body Control Module) that fails to process signals correctly. Having brake lights constantly on is quite hazardous—they can be misread by trailing vehicles at night, increasing rear-end collision risks, and also drain the battery. My advice is to promptly inspect the switch and wiring. For DIY fixes, manually testing and resetting the switch is an option; otherwise, head straight to a repair shop to get it sorted—safety comes first.

[DelJocelyn]

Many BYD S7 owners have been puzzled by the issue of the brake lights staying on constantly. The root cause is mostly a failed brake switch - that small component installed on the pedal can get stuck or wear out over time, preventing signal reset. Other possibilities include short circuits or open circuits in the wiring, such as loose connections allowing water infiltration causing shorts, or a burnt-out relay while the lights remain powered. This type of malfunction is easily misdiagnosed due to the complexity of electronic systems - even CAN bus signal issues can trigger false illumination. For diagnosis, I first use an OBD scanner to read fault codes for clues, then check if the switch resistance is normal. Persistent brake light activation isn't trivial - it increases accident risks while driving. My standard procedure is to temporarily disconnect the battery to prevent excessive discharge, then have a professional technician make proper repairs.

[VanJuniper]

My BYD S7 had the same issue before, with the brake light constantly staying on, which really startled me. It was mainly due to the worn-out brake switch that failed to reset when the pedal rebounded, causing the light to remain lit. It could also be caused by poor circuit contact, like corroded or loose connectors, leading to erratic current flow. This problem is quite annoying, especially when driving at night, as it may mislead the following vehicles and increase the risk of rear-end collisions. I immediately pulled over, turned on the hazard lights to ensure safety, and then tried gently tapping the switch or checking the fuse box—in the BYD S7, the fuse location is easy to find. If I couldn't fix it myself, I would directly tow the car to the 4S shop to prevent a minor issue from escalating.