Honda, Nissan deepen software alliance

HONDA and Nissan have taken another significant step in their post-merger partnership, agreeing to jointly develop and standardise key electronic hardware and software for next-generation software-defined vehicles (SDVs).

The agreement, announced this week, will see the Japanese manufacturers establish common specifications for high-performance electronic control units (ECUs), vehicle operating systems, middleware and vehicle-control software, with the resulting technology earmarked for production vehicles from fiscal 2029 – the Japanese financial year ending March 2030.

It represents the most concrete outcome yet from the strategic relationship retained by Honda and Nissan after their proposed corporate merger collapsed in February 2025.

As previously reported by GoAuto, the companies first signed a memorandum of understanding in March 2024 to examine cooperation on electric vehicles, e-axles, battery technology, software platforms and procurement as both sought greater scale against increasingly competitive Chinese manufacturers and Tesla.

Those discussions subsequently expanded into plans for a full business integration before breaking down when Honda proposed a structure that would have effectively placed Nissan under its control.

Despite abandoning the merger, both companies pledged to maintain cooperation around electrification and vehicle intelligence – an undertaking now formalised around some of the most costly and complex components of future vehicle development.

Under the new agreement, Honda and Nissan will jointly develop standardised high-performance computers using system-on-chip processors, along with zone ECUs responsible for controlling different areas of a vehicle.

The companies will also collaborate on the in-vehicle operating system and important elements of middleware and control software.

Modern vehicles can contain dozens of individual control units responsible for everything from powertrain and battery management to infotainment and driver assistance.

SDV architectures increasingly consolidate these functions into a smaller number of more powerful computers, simplifying wiring and hardware while allowing features to be added or upgraded through software.

Honda and Nissan said common hardware and software should allow them to share development resources, reduce engineering costs and accelerate product development while gaining economies of scale.

The companies regard SDVs as central to both electrification and vehicle intelligence, areas in which Japanese manufacturers have faced increasing pressure from Chinese rivals able to develop and update digital vehicle functions at a faster rate.

For Nissan, the agreement also dovetails with its independently developed Open Scalable Software Platform and wider push toward AI-enabled vehicles.

As GoAuto reported in July, Nissan says new cloud-based artificial intelligence tools can cut some software development tasks from months to hours, with the technology intended to support more frequent over-the-air updates and increasingly sophisticated automated-driving systems.

Honda and Nissan have not detailed which future models will first use their common architecture, nor confirmed what powertrains those vehicles will employ.

However, the latest agreement may not be the end of the collaboration…

Both companies said they would continue examining opportunities to deepen cooperation, while reports in Japan have previously suggested joint vehicle programs – particularly for larger North American models – remain under consideration.

For now, the agreement gives Honda and Nissan a shared technological foundation without reviving the contentious ownership structure that brought their proposed merger undone.