KARIYA, Japan -- Toyota Group megasupplier Denso Corp. was late to the self-driving car game, but executives now say its sales of the technology will quadruple in the next five years. Denso will achieve the upswing with a little help from friends -- some old, but many entirely new.

Among the old is Toyota, Denso's biggest customer and its No. 1 shareholder. Denso expects Toyota's big global volumes to help drive down the costs of the pricey advanced-safety and self-driving systems.

But Denso also will aggressively court new high-tech partners who have expertise that Denso lacks. The supplier of mostly powertrain parts and air conditioning has been on a partnering binge that is set to continue in 2017.

This represents a strategy shift for the world's No. 4 parts maker.

In true Toyota fashion, Denso has historically tried to develop key technologies in-house. But in an age of software, cloud-computing and artificial intelligence, the Japanese auto parts giant suddenly finds itself playing out of its league. Denso recognizes that, despite its mammoth size and healthy profits, it can't go it alone.

"We want to partner in the areas we are not strong in," said Hiroyuki Wakabayashi, senior executive director in charge of Denso's information and safety technology division, which oversees advanced driver assist systems, or ADAS, and self-driving vehicle development.

Wakabayashi's goal is making it a profit margin pillar.

"The unit that will see the fastest growth is the ADAS area," Wakabayashi said in a Dec. 15 interview at Denso's global headquarters here. "But there is a lot of competition. Everybody feels this is an important area and focusing resources on it."

Denso expects its ADAS sales to explode fourfold to ¥200 billion ($1.70 billion) in the fiscal year ending March 31, 2021, from ¥50 billion ($424.6 million) in the fiscal year ending March 31, 2016. The expansion in ADAS will underpin a 43 percent sales increase in Denso's information and safety systems operations, to ¥1 trillion ($8.49 billion) over that time.

Denso has traditionally lagged German rivals Robert Bosch GmbH and Continental AG in rolling out advanced safety systems that stop a car automatically or help steer the car around curves or around trouble. Denso supplies pre-crash automatic-braking packages to Toyota, but Toyota caused waves by also tapping rival Continental as a supplier for a similar system.

Denso's catch-up plan received a boost in January 2016 with the creation of a dedicated ADAS unit. Stocked with 130 software engineers, hardware specialists, system designers and salespeople, its mission is to review nascent technologies and pick the best combinations for production.

Partnering with outside companies is key to the push.

In 2016 alone, Denso has embarked on a half-dozen tie-ups.

In October, it paired with Sony Semiconductor Solutions Corp. on a new vision sensor that can better detect pedestrians at night. It also agreed with Toshiba Corp. to jointly develop an artificial intelligence called deep neural network-intellectual property, which uses algorithms modeled after human brainwaves to recognize the driving environment around the vehicle.

A month earlier, Denso took majority control of Fujitsu Ten Ltd., a Japanese information and communication technology company. That acquisition will strengthen Denso's development of ADAS, millimeter-wave radar and other technologies that underpin self-driving cars.

Earlier in the year, Denso also established a technical advisory contract with an artificial intelligence expert from Carnegie Mellon University, a hot spot for robotics engineering.

It also established a new company in Germany to develop image recognition technologies.

Moreover, it formed a joint venture with NEC Communications Systems Ltd. and eSOL Co., a Japanese embedded software company, to work on software that can support high-speed data communication, high-quality security and high-performance microcomputers in cars.

"That will continue," Wakabayashi said of the search for partners. "It's not finished yet."