The NBTC conducted a field investigation in Thonglor to check for interference causing motorcycle starting failures. They discovered overlapping use of the 433 MHz frequency and ordered agencies to reduce their signal strength.
At 10:40 a.m. on 5 March 2026, on Inthraporn Road, Soi 10, Thonglor area, Plubpla subdistrict, Wang Thonglang district, Bangkok, officials from the National Broadcasting and Telecommunications Commission (NBTC), specifically the special operations unit “Phra Phai,” along with NBTC District 11 office, visited the site to investigate numerous motorcycle users’ complaints about starting failures. This followed reports and ongoing monitoring since early in the week.
During the investigation, officials brought a spectrum analyzer to measure signals at the problem site and asked a group of riders to bring motorcycles exhibiting the issue for testing. They found that when a rider turned off the engine, a "beeping" sound occurred, after which the motorcycle could not be started normally.
Officials then used signal detection equipment to trace the source to a transmission antenna atop a building in the area. They coordinated with relevant agencies to reduce the signal power of the frequency. As a result, motorcycles could start normally again. Afterwards, officials conducted further signal inspections around the area to prevent recurrence.
Initial findings by NBTC officials indicated the problem was caused by overlapping use of the 433 megahertz (MHz) frequency band, which is the same frequency used by motorcycle remote keys. This interference disrupted the signals, preventing the starting system from functioning.
Officials deemed it necessary to instruct the agencies using that frequency to lower their signal levels because asking motorcycle manufacturers to change the remote key frequency systems would be difficult, as these devices are factory-produced according to standardized specifications.
The NBTC stated that the issue in the area has been resolved and motorcycles are now operating normally. They encouraged the public to report similar problems or other risk points to the NBTC office so that officials can investigate and address them promptly.