Why can't the BYD Surui start when the brake light is not on?

[DeMelanie]

Possible reasons include a short circuit in the "main wire," a short circuit in the light, or a blown fuse. Here is an introduction to the BYD Surui: 1. Exterior: The Surui features a more stylish and elegant design, with a front face that integrates dual chrome strip designs with lens-style headlights. The ruby-like fully embedded LED taillight assembly perfectly connects with the waistline that runs from front to rear, exuding a sporty and fashionable appeal. The dazzling rear brand-illuminated logo showcases modern technological beauty, offering a more enchanting nighttime effect to meet personalized needs. The side and rear of the Surui also adopt a minimalist design style, with simple lines creating a highly cohesive visual effect. 2. Interior: The Surui's black and beige dual-tone interior is harmoniously matched, complemented by glossy piano black finishes that are refined and delicate, highlighting both fashion and technology. The new multifunctional steering wheel integrates shortcut keys for multimedia control, instrument function settings, cruise control, and more, offering smart and convenient operation. The 7-inch high-definition capacitive touchscreen combines functions such as in-car digital TV, intelligent noise-canceling radio, DVD, USB, SD, AUX, Bluetooth phone, and Bluetooth music, making entertainment and information easily accessible.

[SanNatalie]

My BYD Surui encountered the same issue a couple of days ago—it wouldn't start, and I noticed the brake lights weren't working either. For these push-to-start vehicles, the system requires a brake signal to power on. The brake lights and start signal share the same brake switch, much like how a light switch at home controls both the lights and appliances. If the switch fails, both functions stop working. The problem could either be due to aged or stuck contact plates on the switch at the top of the brake pedal or a short circuit in the wiring. If you're DIY-inclined, you can check under the dashboard to see if any wiring harnesses near the brake pedal have come loose. Replacing the switch involves removing the lower steering wheel cover, and using a multimeter to test the switch's continuity is the most accurate method. Last time, my car had a broken spring inside the switch, causing the plunger not to pop out when braking, leading to poor contact. These kinds of faults are particularly annoying as they might leave you stranded unexpectedly.

[ValeriaRose]

As a veteran owner who has driven the Suri for five years, I've found that when the brake lights don't work and the car won't start, it's often due to a faulty brake position switch. This switch controls both the brake lights and sends a start signal to the ECU. It has a simple structure but plays a crucial role. The plastic housing can deform over time, and the copper contacts inside may oxidize or break. Humid weather during rainy days makes short circuits more likely. Additionally, the wiring harness near the steering column can get worn out and ground if repeatedly rubbed by floor mats. I once encountered this situation after modifying my floor mats. In emergencies, try stomping the brake pedal forcefully about twenty times - this might occasionally dislodge stuck contacts, but it's only a temporary fix. Leaving it unrepaired long-term isn't just dangerous; the transmission lock mechanism might also enter protection mode.

[RobertDella]

When encountering a BYD Surui's brake light not illuminating and failure to start, focus on three key checks. First, inspect the brake switch—a small black box on the pedal bracket. Unplug its connector and directly bridge the two contacts; if the light turns on, the switch is faulty. Next, examine the STOP 10A fuse in the fuse box—a blown fuse disrupts the entire circuit. Lastly, trace the wiring, paying special attention to the harness connector under the left front sill plate for water ingress or oxidation. Such issues often emerge suddenly during rainy seasons, as aged door seals may leak and soak the wiring. Once, during a rescue, rodent damage was found chewing through the wires. After repair, remember to use a diagnostic tool to clear any ECU-stored startup error codes to prevent accidental anti-theft lockout triggers.

[DiCorbin]

The core issue with the BYD Surui's condition lies in the brake light switch linkage mechanism. The pedal switch features a dual-channel design: one circuit controls the brake lights, while the other serves as the activation signal. Simultaneous failure is most likely due to a switch assembly problem. The switch is mounted on the firewall pedal bracket, and if the rubber dust cover is torn, dust ingress can cause it to jam. Be careful not to break the positioning clips during disassembly. For testing, you can use a wire to connect the yellow-black and green wires of the switch socket to simulate the signal. The switch itself costs around twenty yuan, but labor costs are high, so it's recommended to have the 4S shop perform a brake light inspection at the same time. Wiring issues often occur near the driver's footwell, where the harness may break internally due to prolonged tight bundling and vibration. Remember to regularly inspect the white limit buffer block on the pedal linkage, as excessive wear can misalign the switch travel.

[SanLayla]

From a circuit design perspective, the Surui's brake lights and starting system share the same signal source. When the brake pedal is pressed, the switch activates two circuits: one powers the brake lights, and the other informs the BCM that the starting system is ready. If the switch fails, both circuits become inoperative. There are three common faults: the internal spring of the switch fatigues, preventing the contacts from closing; the wiring harness breaks at the steering column; or the brake light circuit shorts and blows a fuse. For DIY troubleshooting, first check under the driver's seat by shaking the wiring harness to listen for any short-circuit sparking sounds. Pay special attention to the corrugated tubing section of the wiring from the pedal to the steering column. The most challenging case encountered was after installing a cruise control modification, where incorrect wiring into the brake light circuit caused system conflicts and error reports. For non-professionals, visiting a 4S shop to read the data stream with a diagnostic tool is the most reliable solution.