‘No More Fuses:’ How GM’s New Architecture Will Transform Gas Cars, Too

General Motors says it’s trying to create “the car of the future.” It’s powered by software that’s continually updated, full of advanced features, and increasingly autonomous. But given recent trends in the United States and beyond, it’s clear that some of those cars of the future will still run on gasoline.

As much of the auto industry is figuring out new, high-tech, lower-cost ways to build electric vehiclesGM wants to run a similar playbook with its gas-powered cars, too. More than that, it’s working on a single electrical system architecture and software setup that can underpin all of its vehicles—from compact gas cars sold in Latin America all the way up to full-size electric Cadillac SUVs.

“In 2028, we’ll launch our next-generation centralized compute system, starting with the Cadillac Escalade IQ,” said David Richardson, GM’s senior vice president of Software and Services Engineering. “It’s propulsion-agnostic, which means that this technology will run across both electric and gas vehicles… and the payoff is massive.”

That’s no easy task, as executives and engineers told me at the GM Forward tech event in New York City yesterday. But if they can pull this off, they may take one of the most unique things about EV development and apply it to gas-powered cars that require fewer parts and maintenance, use less energy, and cost less to run over time.

And it could mean the end of fuses, for one thing.

Get In The Zon(al Architecture)

GM calls this a “centralized compute architecture.” To understand why it matters, it helps to understand how your car’s electrical systems developed in the first place.

The first engine control units (ECUs) were born with electronic fuel injection control modules, which became widespread in the 1980s. Over time, as cars became more advanced, more computer systems were added, too. Anti-lock braking systems. Climate control systems. Your infotainment system and navigation system. Safety systems. Door and window mechanisms. And in most cases, these were designed and made by different companies than the automakers themselves, with very little communication and commonality between all the different parts. Oh, and the software that controls them all might be made by even more outside parties.

Just as it sounds, this was a kind of piecemeal approach to building a car. It’s like making something out of a giant, random old pile of Legos your kid keeps in a bin, and not making something purposeful, like a dedicated Lego set. If you were to design a car from scratch today, you wouldn’t do it this way. You’d want to build a car with as few separate computers as possible—and you’d network them across one single, modern software stack.

Today, this is how most cutting-edge EVs are built. It’s called a “zonal architecture,” with the different “zones” within the car controlled by a small set of computer systems. The old way of doing things is called a “domain-based architecture.” Zonal architectures were pioneered by Tesla, and companies like Rivian and the Chinese carmakers are running with those ideas.

Sticking with the old domain-based setup for an EV means way more wiring, more parts, more software complexity—and a better capacity for software updates that can add new features or fix bugs across the entire car.

Naturally, these are all things carmakers want from their next-generation EVs. Battery costs remain high, so you need to cut costs and innovate in manufacturing with the rest of the vehicle. Plus, they all have big dreams of revenue through advanced software features.

But how do you deliver those innovations on gas cars, at a time when EV sales are slowing, tax credits have expired, and car companies like GM realize they won’t be going all-electric anytime soon?

In this case, enter what GM calls “the centralized compute architecture.”

GM’s Approach Covers EVs And Gas Cars

It’s one thing for an EV-only company to go to zonal architectures. But if you’re GM, and you make a lot of cars globally with gas and electric powertrains, trying to do things the new way and the traditional way at once presents a costly problem. Thus, it had to find a way to cover both.

The centralized architecture does exactly that, Gary Cygan, the director of platform engineering at GM, told me. It dramatically reduces the number of vehicle modules by combining them into a few smaller units.

One liquid-cooled central computer manages the functions of 12 different traditional modules and does the “thinking” for the entire car; another module handles connectivity, like the radio, Bluetooth, WiFi, and 5G wireless; and finally, three “aggregators” act as relays for signals from hundreds of different sensors back to the main computer.

So what does it mean for the consumer? A lot, Cygan said. “We’ve moved away from standard fuse boxes,” he said. The aggregators handle those functions instead. And it means the quicker addition of new features over time. “We’ve added significant capability increases, so it’s not just like, take what this does and put it in one box,” Cygan added. “We’re adding compute upgrades, connectivity upgrades, and vehicle communication upgrades.”

It also means lower costs and less complexity, he said—but since GM is adding more to these systems, the effect on pricing for consumers is unclear. “If we were to take the exact same capability that you have in here and move to this architecture, it’s a lower material cost,” he said. “But we’re adding capabilities, we’re adding better silicon, we’re adding the ability to control circuits on the car at the same time.”

In a sense, this will allow GM to build its gas cars and EVs in a similar way over time. But those powertrains still have diverse needs that it’s working through. Take cooling the central computer, for example.

“On an EV, you can tap into the system that already cools the battery,” Cygan said. “But on an ICE [internal combustion engine] vehicle, where do you get coolant for it, because the coolant that is in the engine system is much warmer than what you need, right? So figuring out how to do that on ICE is a challenge.”

Interestingly, while this system will debut on the Escalade IQ in 2028—which GM confirmed is the current model, not a forthcoming one—it will be added to the rest of the GM lineup afterward. And that includes any current-generation cars, as this setup won’t require a whole new model to implement.

Cygan also thinks it could be an upgrade in terms of repairability. “There are fewer things that can go wrong, fewer things that if they go wrong, it takes time to diagnose,” he said.

GM’s Software Dreams

At the GM Forward event, the carmaker made clear that it sees its future in robotics, AI, and autonomous vehicles. But it’s going to have to deliver some of that technology with gas-powered cars, for now. From its perspective, this is a better setup for consumers because of the features it will deliver.

“It means vehicles that are always up to date, delivering 10 times more software updates than our previous system,” Richardson said. “It means a self-driving system that reacts in milliseconds, and a vehicle network with 1,000 times more bandwidth for faster connectivity, enabling richer entertainment and future AI workloads. So it’s a leap to a vehicle that can think and react as one.”

It also means the standardization of software across all these cars, which should save costs as well. But whether this architecture will be viable from the start and deliver on all these promises remains to be seen. After all, we’ve seen plenty of teething issues with new software platforms, including those from GM.

Yet it’s clear that even if customers aren’t ready to break up with gas quite yet, whatever they drive next could deliver a lot of learnings from EVs. After all, GM’s big dreams of autonomy and software depend on it.