On the evening of May 8. Mr. Li from Leiyang, Hunan, was parking his newly purchased Xiaomi SU7. which he had owned for less than a month, when the brakes seemingly failed, triggering an alarm inside the car. The screen displayed four abnormal messages, including "Brake System Fault." Despite the slow reversing speed and the vehicle stopping automatically, Mr. Li's SOS emergency call from inside the car went unanswered. An hour and a half later, local road rescue arrived and towed the vehicle to the Changsha Delivery Center. Strangely, after inspection, the car 'self-healed,' and after-sales stated it could be driven away anytime. However, Mr. Li did not dare to and wants to find out the cause of the brake failure.
Car Owner: No Brake Resistance Felt, 24-Hour Rescue Hotline Unanswered
On May 12. Mr. Li recounted the incident involving his Xiaomi SU7 to Dahe Daily · Yu Video’s "See" reporter.
Mr. Li’s Xiaomi SU7 is the Standard Founder Edition, priced at 215.900 yuan. He picked it up on April 10 at the Xiaomi Delivery Center in Xiangjiang International Auto City, Changsha. The incident occurred on the evening of May 8 near the roadside of Luqifeng Bridge on Xihu East Road, Leiyang, Hunan.
"I was looking for a parking spot by the roadside, and while reversing, the problem suddenly occurred. I pressed the brake pedal, but it felt empty, with no resistance. The car then issued a few warning sounds that quickly disappeared." The car information provided by Mr. Li showed four abnormalities on the screen: "Brake Performance Limited, Drive Carefully," "Brake System Fault, Park Safely," "Auto Parking Fault," and "Hill Start Assist Fault."
Mr. Li said he noticed the brake issue while correcting the direction as the car was almost parked.
"The car's battery was normal, it hadn't lost power. Since I was reversing at only a few kilometers per hour, the regenerative braking gradually stopped the car." Mr. Li said his Xiaomi SU7 had traveled 2005 kilometers.
Mr. Li claimed he called the Xiaomi Automobile hotline at 400-182-6888. but no one answered after nearly half an hour. He then used the car's SOS emergency call system, which redirected him to the emergency road rescue center, where again, no one answered.
"The incident happened at 7:43 PM, and I called for rescue around 7:50 PM. Road rescue arrived at 9:10 PM. The road rescue hotline is supposed to be available 24/7. but no one answered for a long time," Mr. Li said.
Inspection Results: Software Misjudgment?
Mr. Li told the reporter that after local road rescue arrived on the night of May 8. they towed the car to the Xiaomi Delivery Center at Xiangjiang International Auto City in Changsha overnight. The staff checked it overnight, and the next morning they provided a response.
"The diagnosis was that their electronic software had an issue. The car has a main brake and an auxiliary brake. The electronic software mistakenly intervened, misidentifying an issue with the main brake, which led to the brake fluid being diverted to the auxiliary brake, causing a few seconds of no braking and thus weak braking performance."
Mr. Li said experts from Beijing also inspected the car overnight. "The experts said the same thing, and after-sales told me that the brakes did not fail entirely and would stop after a while. They suggested my subjective feeling was inaccurate, meaning the brake pressure decreased, which led to the lack of foot feedback."
Mr. Li disagreed with the claim that the brakes did not fail. "When I checked the data, I saw that the pressure value was zero for a few seconds when I pressed the brake. When I asked them about it, they didn't respond."
Mr. Li told the "See" reporter that Xiaomi's after-sales initially showed him the brake pressure data, but he couldn't obtain it later.
"If driving at high speed, a brake pressure drop to zero for one or two seconds could result in a crash," Mr. Li said.
Car Owner: Fault Automatically Cleared, After-sales Asked Me to Continue Driving
The reporter obtained a feedback document on the vehicle condition: the car has two brake controllers (main BCP and auxiliary BCS). Normally, the main BCP responds to the driver's braking demand, while BCS assists as a backup. If the BCP degrades, BCS directly responds to control braking. On May 8. BCP software misidentified an issue, leading to a degraded BCP braking function, and the screen displayed a brake system fault. The driver's pedal feel weakened. On May 9. the vehicle inspection found that around 2:53 AM, the brake fault warning disappeared. The conclusion was that after BCP self-check, the error state disappeared, and BCP braking feel returned to normal.
Mr. Li told the reporter that the fault warning was still displayed when the car was towed. Upon reaching the delivery center, the fault display had indeed cleared. "They explained that the car had self-repaired and could be driven away anytime. Can I dare to drive it?"
Mr. Li provided a WeChat screenshot showing after-sales personnel stating that the vehicle system self-check program had restored functionality on May 9 and the car was ready for pickup. If he didn’t want to use the car anymore, he could opt for a replacement or refund approved by the headquarters.
Mr. Li said Xiaomi offered a replacement or refund per regulations but he wanted to know if the car truly experienced brake failure and why the road rescue hotline was unanswered for so long.
Mr. Li received feedback that Changsha Xiaomi after-sales was reporting the issue to the headquarters, but it was still in progress.
On the afternoon of May 12. Dahe Daily · Yu Video’s "See" reporter contacted the Xiaomi Delivery Center at Xiangjiang International Auto City in Changsha. A manager said they needed to collect the reporter's personal information and would assign someone to answer the questions, but as of press time, no response was received from Xiaomi.
