The Ministry of Internal Affairs and Communications (MIC) of Japan has issued the Ministerial Regulation No. 91 regarding the partial amendment to the Radio Act 1950 concerning Tire Pressure Monitoring Systems (TPMS) and keyless entry systems. Based on the amendment regulations, the radio frequencies permitted for TPMS and keyless entry systems in Japan have been expanded to frequencies exceeding 433.05 MHz but not exceeding 434.79 MHz.
This partial amendment to the Radio Act 1950 enters into force on the date of its promulgation, namely 24 July 2026. Therefore, in this article we will discuss all important notes from this amendment regulation and its impact to the process of Type Approval in Japan.
Key Notes of Partial Amendment to Japan’s Radio Act 1950
The Ministerial Regulation No. 91 regarding this partial amendment presents the document in both its pre-amendment and post-amendment versions. Based on the following table, which details one of the amendments for TPMS and keyless entry systems, the underlined text (yellow highlight) in the “Before Amendment” column is replaced by the corresponding underlined text (yellow highlight) in the “After Amendment” column.
| After amendment | Before amendment |
| (Radio stations not requiring a license) Article 6 [omitted] [2.3 omitted] The radio stations specified by Ministry of Internal Affairs and Communications Ordinance as referred to in Article 4, Item 3 of the Act shall be those listed below. [Abbreviation] (ii) Equipment that complies with the conditions set forth below and conforms to the radio wave types and antenna power separately notified by the Minister of Internal Affairs and Communications (hereinafter referred to as “specified low-power radio stations”). [1–13 omitted] 14. Equipment used for a tire pressure monitoring system (referring to radio equipment of a radio station installed primarily in a motor vehicle that automatically transmits data regarding tire pressure status and the like; the same applies in Article 3, Item 3-2 of the following Article) or a keyless entry system (referring to radio equipment of a radio station that performs wireless communication primarily for the operation and management of a motor vehicle; the same applies in the same item), and which uses radio waves with a frequency exceeding 433.05 MHz but not exceeding 434.79 MHz. [3–11 omitted] Article 6-2 The functions specified by the Ordinance of the Ministry of Internal Affairs and Communications referred to in Article 4, item (iii) of the Act shall be those set forth in the following items. [1–3 omitted] 3–2 Tire pressure monitoring systems and keyless entry systems that automatically transmit or receive identification codes. [4 and 5 omitted] | (Radio stations not requiring a license) Article 6 [same as above] [2.3 same as above] 4 [same as above] [All above] (ii) [same as above] [1–13 same as above] 14. Tire air pressure monitoring system (referring to a tire pressure monitoring system as defined in Article 49-14, item 5, subparagraph (b) of the Equipment Regulations) or a keyless entry system (referring to a keyless entry system as defined in the same subparagraph (b)), and which use radio waves with a frequency exceeding 433.795 MHz but not exceeding 434.045 MHz. [3–11 same as above] Article 6-2 [same as above] [1–3 same as above] [New] [4 and 5 same as above] |
One of the amendments specified in Ministerial Regulation No. 91 are closely related to the expansion of radio frequency ranges for TPMS and keyless entry systems in Japan, expended from 433.795 – 434.045 MHz to 433.05 – 434.79 MHz. This amendment document also stipulates the removal of technical requirements regarding enclosure configuration and construction.
Impact on Japan Type Approval
Adopting the radio frequency 433.05 – 434.79 MHz for TPMS and keyless entry systems aligns Japan with international standards for these technologies used in many countries. This amendment offers benefits to manufacturers, as they no longer need to produce TPMS and keyless entry specifications specifically for the Japanese market.
The change in radio frequency ranges for TPMS and keyless entry systems from 433.795 – 434.045 MHz to 433.05 – 434.79 MHz does not invalidate existing MIC certificates. However, if manufacturers wish to utilize the new frequency ranges, they must obtain new MIC certification to allow their TPMS and keyless entry devices operating within the new frequency ranges. You may download a copy of the Ministerial Regulation No. 91 in the file below.
Conclusion
The implementation of Ministerial Regulation No. 91 for partial amendment to the Radio Act 1950 may cause confusion among manufacturers and MIC certificate holders in Japan. Therefore, manufacturers and suppliers need to check whether their 433 MHz frequency complies with the new frequency range requirements stipulated in Ministerial Regulation No. 91. Please do not hesitate to contact DIMULTI Indonesia via email at info@narmadi.com if you have any questions regarding this new regulation.
