Nissan and Honda have signed a joint development agreement to standardize core electronic control units (ECUs) and vehicle software, both companies said on Monday, in their most concrete collaboration since merger talks collapsed in February 2025.
The automakers will standardize several of the ECUs at the centre of next-generation software-defined vehicles, along with the in-vehicle operating system, key parts of the middleware and vehicle control software running on them to reduce development costs and gain economies of scale.
The electrical and electronic architecture built around those components is planned for use in both companies’ next-generation vehicles from fiscal 2029 onward — a Japanese fiscal year beginning in April 2029.
The units covered are high-performance main computers built on systems-on-chip and zone controllers that oversee individual areas of a vehicle.
What the Agreement Does Not Cover
The announcement is confined to shared componentry and software layers. It does not describe joint vehicles, shared platforms, a new corporate entity, capital ties or any equity arrangement, and it names no models, investment figure or development split.
Both companies describe the deal as part of an existing strategic partnership under which they “continue to explore opportunities for collaboration” — language that frames this as one concrete outcome inside a broader, still-provisional relationship rather than a comprehensive tie-up.
Mitsubishi Motors is not a party to it, but says it may become one.
In a statement on Monday, Nissan’s alliance partner said it was considering joining the collaboration and remained in discussions with both companies on potential areas of cooperation.
That matters commercially.
Nikkei reported in June that Mitsubishi was expected to make a financial contribution to the ECU programme, with procurement and development terms to be settled later.
Three carmakers adopting the same family of controllers and semiconductors would carry more weight with suppliers than two.
The Context, Stated Precisely
Nissan and Honda announced on December 23, 2024 that they had signed a memorandum of understanding to explore integrating their businesses under a joint holding company, with a listing planned for August 2026 — a month that has now passed with no such company in existence. Mitsubishi was included as a junior partner.
Those talks ended on February 13, 2025. Reporting at the time attributed the collapse to Honda’s push to make Nissan a subsidiary rather than an equal partner, a structure Nissan would not accept.
The combination would have created one of the world’s largest automakers, valued in coverage at around $60 billion.
The three companies said then that they would continue a strategic partnership covering batteries, autonomous driving, software and electric vehicle technology. Today’s agreement is a product of that surviving arrangement.
It is not a resumption of merger talks, and nothing in the announcement suggests one.
The relative positions have also shifted since.
Nissan was widely read as the weaker party in 2024; Honda spent the first half of 2026 cancelling electric vehicle programmes of its own.
Ivan Espinosa replaced Makoto Uchida as Nissan CEO in April 2025 and is running a turnaround the company calls Re:Nissan.
How It Was Signalled
Honda President Toshihiro Mibe told the company’s annual shareholders’ meeting in June that conversations with Nissan were “quite far along,” with some elements close to announcement.
Nissan chief executive Ivan Espinosa said in July that news was likely in three areas: US manufacturing capacity, hardware for electric vehicle architectures — with an open question over “whether we should have a common software stack, up to what level” — and battery supply for hybrids in the US.
Today’s agreement answers the second of those three, partially. The other two remain open — and the North American thread is the more consequential.
Nikkei reported the deal on Saturday, ahead of the announcement. Honda told Reuters at the time that no deal had been decided; a Nissan spokesperson said the company was exploring various possibilities.
