In early November 2025, residents around Bo Ho, Ben Do Street in Cam Pha Ward, Quang Ninh Province experienced sudden failures of smart keys for cars, motorbikes, and rolling doors.

Vehicle owners said the smart key only worked normally after they moved about 20 meters away from the area. The issue caused concerns about possible signal interference or high-tech theft.

After receiving reports, the Radio Frequency Center Region V (under the Authority of Radio Frequency Management) coordinated with the Department of Science and Technology of Quang Ninh Province to conduct on-site signal measurements on November 12, 2025.

The analysis showed that the interference had originated from a TRND16 wireless vibrating buzzer used for calling drinks in a cafe in the Bo Ho, Ben Do area.

The device had no conformity stamp and suffered a technical fault, causing it to emit continuous signals in the 433.05–434.79 MHz band, which is license-exempt for remote-control devices such as smart keys under Circular 08/2021/TT-BTTTT.

After identifying the cause and disconnecting the interference source, all smart keys of cars, motorbikes, and rolling doors in the area returned to normal operation.

QR scanning-device interference

In August 2025, residents living and working in the area around houses No 253, 255, and 269 Kim Ma (Hanoi) encountered a similar phenomenon where motorbikes using smart keys could not be started.

Upon receiving feedback from residents via Fanpage, the Regional Radio Frequency Center I, belonging to the Radio Frequency Department, quickly investigated the problem. After conducting measurements, the authorities identified the "culprit" causing the interference as a QR code scanning device used to compare Vietlott results.

Immediately after the device was dealt with, the smart keys of all vehicles in the area returned to normal operation.

Meeting radio frequency standards

The main cause of these incidents is that radio frequency application devices, when operating, either fail to meet quality standards or experience technical malfunctions.

In May 2025, the Radio Frequency Department detected several cases of interference from cable TV modem power adapters, affecting the operation of car and motorbike smart keys in HCMC.

A representative of the Radio Frequency Department shared that immediately upon receiving the information, Regional Radio Frequency Center II established an interference handling team, accessed the site, surveyed, and measured. 

Through professional technical analysis and assessment, Regional Radio Frequency Center II quickly found the cause: a faulty AC/DC power adapter used to supply power to a resident's cable TV and Internet modem.

Due to the faulty adapter, it emitted signals in the frequency range of 10kHz-1000kHz, which propagated along the coaxial cable and radiated into the environment, causing interference on the 125 kHz frequency of car and motorbike transceivers.

According to the owner, when the old adapter broke, they bought an unverified replacement adapter. After listening to an explanation of the situation, the resident cooperated by handing over the device to the authorities for regulated disposal.

In April 2024, an infrared anti-theft fence system was identified in Nha Trang, Khanh Hoa as the source of radio interference that prevented motorbike smartkeys in the surrounding area 

Many car owners had complained that their smart keys repeatedly failed to start. Several rolling doors and automatic doors were also affected and became inoperative.

Survey and measurement results showed that within a radius of about 100 meters from the reported area, authorities detected continuous transmissions on the 434 MHz frequency.

Through technical procedures, inspectors identified that the 434 MHz signal was emitted from an electronic anti-climb fence (infrared anti-theft barrier) installed on the wall of a nearby household, which had malfunctioned. This device was confirmed to be the “culprit” causing interference to smart key systems.

Multiple cases of smart key and rolling-door signal interference have occurred across the country. The main cause was devices that use radio waves but fail to meet technical standards during operation.

After the incidents, the Radio Frequency Department recommended that organizations and individuals should only buy and use transmitting devices that have clear origins, are conformity certified, and have a regulation-compliant conformity stamp affixed.

Counterfeit, smuggled, or technically unchecked devices can cause radio frequency interference, affecting control devices, and security and civilian communication systems.

If people detect unusual smart key interference or signal loss, they can report it via hotline 0862.92.92.92 or to the local Department of Science and Technology.

Thai Khang