The two automakers will each acquire a 10% stake in the joint venture, on par with Isuzu Motors and Hino Motors, while Toyota will hold a 60% stake, they said.
"With Suzuki and Daihatsu joining the project and working together, we'll be able to expand our circle of cooperation to not only cover commercial vehicles but also mini vehicles," said Toyota President Akio Toyoda.
"With this expansion, I believe that we'll be able to take one step closer to a better mobility society," Toyoda said.
The move comes as Japanese automakers face growing competition from tech giants and other rivals making electric and driverless cars.
Toyota, Isuzu and Hino launched the Commercial Japan Partnership Technologies Corporation in April to bolster their competitive edge in connected, commercial vehicles.
Daihatsu's president Soichiro Okudaira said joining the pact and introducing connected, mini-commercial vehicles would allow data sharing, a major benefit for companies to provide better services to customers and improve logistics efficiency.
(Reporting by Eimi Yamamitsu; Writing by Ritsuko Ando; Editing by Louise Heavens)