Asian giant BYD has begun a comprehensive return process to dealerships involving 88,981 copies of the Qin Plus DM-i model within Chinese territory. The plug-in hybrid sedan, which is among the brand’s most sold, presented a critical vulnerability in the lithium battery pack that could directly compromise the integrity of the occupants. The units that need to undergo this review were assembled on production lines between the first month of 2021 and September 2023.
Technical details about the power management system defect
The government body responsible for monitoring local commerce, known as the State Administration for Market Regulation (SAMR), has already received official documentation detailing the problem. According to the published technical reports, the root of the anomaly lies in a variation during the assembly of the electrical harness responsible for capturing the voltage from the energy accumulator. This inaccuracy in manufacturing causes incorrect data to be sent to the car’s electronic brain.
Given this misreading of parameters, the system can suddenly cut traction while the driver is traveling on public roads. In more extreme scenarios, the manufacturer does not rule out the possibility of overheating and dangerous thermal events. The automaker made a point of highlighting that the probability of a fire occurring is statistically low, classifying the recall as a strictly preventive attitude, with all repair costs absorbed by the company itself.
Consequences of continuous wear on high voltage components
The mechanical origin of this failure is concentrated in the way the cables were accommodated inside the high voltage casing. Engineering documents indicate that manufacturing tolerances allowed the harness to be subjected to abnormal physical pressure. This constant crushing impairs the durability of the insulating material and distorts the vital electrical signals that are dispatched to the Battery Management System (BMS).
As the months go by and the natural vibration of daily use, the degradation of this wiring prevents the onboard computer from knowing exactly what the charge level and the health of the individual cells are. As BYD widely uses Lithium-Iron-Phosphate (LFP) chemistry in its Blade batteries, which have a very flat discharge curve, millimeter precision in voltage reading is absolutely essential to prevent the software from incorrectly calculating autonomy. Imminent danger occurs if the flow of electricity to the propellant is interrupted on fast-moving highways, leaving the car unresponsive.
Action plan involves remote technology and mechanical intervention
To immediately mitigate risks, the corporation designed a strategy divided into two fronts. The initial step is based on sending a data package via the internet to update the software of all cars listed in the ticket. This new programming code refines the sensitivity of the algorithm, allowing the computer to identify any suspicious oscillation in the wiring harness early, triggering a visual alert on the instrument panel.
The second phase of the schedule requires owners to take their goods to an authorized network workshop. Specialized mechanics will physically scan the energy storage structure to confirm the integrity of the wires. If technicians find any sign of excessive compression or rupture in the electrical network, the entire part will be exchanged for a new one, without passing on any value to the consumer.
Recent history of summons raises alarm in the automotive sector
The episode involving the Qin Plus DM-i adds to a sequence of mass revisions that the automaker had to manage in recent months, highlighting the bottlenecks in quality control during its accelerated expansion phase. In October last year, the company had already requested the return of more than 115 thousand sports utility vehicles from the Tang DM-i and Yuan Pro lines, also motivated by fire risks originating in the energy compartment.
A few weeks before this event, in September, a different failure in the power converter forced the return of approximately 96 thousand units of the Dolphin compacts and the Yuan Plus SUV, as the component tended to overheat.
The volume of cars that needed to be returned to official garages for critical safety corrections surpassed the 300,000 mark in a very short period of time. To understand the scale of the brand’s recent calls on the Asian market, the numbers are divided as follows:
- Approximately 89 thousand units of the Qin Plus DM-i sedan due to voltage harness failure.
- More than 115 thousand copies of the Tang DM-i and Yuan Pro models due to anomalies in the battery system.
- Around 96 thousand vehicles from the Dolphin and Yuan Plus families due to temperature problems in the energy converter.
Government rigor shapes the future of Asian electric mobility
China’s automotive scene, which currently holds the title of largest consumer of electrified cars on the planet, has come under increasingly severe scrutiny from entities such as SAMR. Past incidents involving several manufacturers have made the thermal stability of lithium-ion cells a national security priority. State audits now investigate everything from the standardization of assembly conveyors to the robustness of the software codes that manage the driving force.
Major industrial conglomerates, including BYD itself and giant suppliers such as CATL and CALB, operate under constant surveillance to ensure that their production methodologies do not deviate from standards of excellence. Beijing’s central administration has a very well-defined goal: to eradicate the catastrophic failures linked to electrification to shield buyers’ confidence and sustain the country’s hegemony in the global energy transition.
Official procedures for scheduling repairs at dealerships
Over the next few weeks, the brand’s relationship team will send notifications directly to cell phone applications and communication channels integrated into affected vehicles. The official guidance is that drivers do not wait for the warning and proactively access the company’s internet portal, where they can enter the Vehicle Identification Number (VIN) to find out whether the specific chassis is part of the defective batch.
While the operating system patch can be downloaded in the home garage, as long as the multimedia panel is connected to a stable 4G or 5G network, visual inspection requires physical movement. The manufacturer’s management reinforced in its communications that ignoring this call compromises the useful life of the asset and puts passengers at unnecessary risk in the long term.
Volume of global registrations ignores technical turbulence
Interestingly, the barrage of security calls did not dampen the public’s appetite for the brand’s products. The October trade balance revealed a significant jump in global deliveries, breaking the barrier of 441 thousand cars invoiced in a single month. The main driver of this growth continues to be the plug-in hybrid (PHEV) fleet, which registered a 31% jump and surpassed the mark of 214 thousand keys delivered.
The segment of cars powered exclusively by batteries (BEV) also demonstrated vigor, standing at around 223 thousand units sold in the same period. The massive preference for hybrid engines in the Chinese market reflects drivers’ search for a smooth transition, combining the low cost of recharging at the socket with the peace of mind of a fuel tank for long journeys, a formula that keeps the manufacturer at the top of the global sales ranking.
