As carmakers integrate 100-150+ chip-based electronic control units in each car, a look at the challenges of an auto industry that is more dependent on software
IEEE SpectrumRobert N. Charette
Context & Ripple Effects
The modern car is already a distributed computing system: IEEE Spectrum counts 100-150+ chip-based electronic control units per vehicle, each running its own firmware, stitched together over the aging CAN bus that the industry has been trying to replace since at least the push for a new in-vehicle networking standard. That architecture was fine when cars were mostly mechanical, but every new feature adds another computer and another line of software a carmaker must integrate.
The strain is now visible across the supply chain. The 2021 chip shortage pushed carmakers to bypass their traditional parts-vendor intermediaries and build direct ties with chip makers, and by 2024 McKinsey pegged automotive chips as a $150B market by 2030. Meanwhile legacy systems are showing their limits in the field: [[a:881101|NHTSA data shows software fixes rose from 6% of US automotive recalls in 2019 to 15% in 2024]].
First-order effects
Parts vendors lose their gatekeeper role on semiconductors as carmakers contract directly with chip makers — the intermediary layer that defined auto sourcing for decades gets squeezed out of its most valuable component category.
Legacy carmakers face rising engineering cost per vehicle model: integrating and testing firmware across 100-150+ ECUs means every recall increasingly requires a software fix rather than a mechanical part swap.
Second-order effects
Chip makers gain direct customer relationships and pricing leverage in a market headed for $150B by 2030, while EU auto chipmakers hedge Western sales weakness by deepening engagement with Chinese OEMs.
Automakers respond by pulling design in-house: GM's Cruise built four self-driving chips internally — including the main brains and sensor-processing silicon — for deployment by 2025, signaling that the highest-value ECUs will be designed by the car companies themselves.
Third-order effects
If the pattern holds, the car consolidates from dozens of federated ECUs toward fewer, more powerful compute platforms controlled by the automaker — the same centralization logic behind replacing CAN — turning the vehicle into a software product with update cycles, not a machine assembled once.
Regulation follows the failure mode: with software already driving a growing share of recalls, safety oversight shifts from inspecting hardware defects to auditing how quickly and reliably manufacturers can patch code in the field.
The trend: The automobile is transitioning from a mechanically sourced product to a software-defined one, with value and control migrating from parts vendors toward whoever owns the compute architecture.
Fascinating stats on how much of software in car will likely be built in-house vs by suppliers. Reminds me of the Wardley map that @adrianco made of fictitious autonomous driving company earlier this week! (Insourced driving module, which needed optionality, outsourced braking ht…
The trend toward self-driving and electric vehicles will add hundreds of millions of lines of code to cars. Can the auto industry cope? https://spectrum.ieee.org/...
Managing complexity: The electric/electronic stack(s), multiple ECUs, and zillions of lines of code, of modern vehicles. Very nice article. https://spectrum.ieee.org/...
1/ Volkswagen Chairman Herbert Dies says, “Software will account for 90% of future innovations in the car.” ..hardly a line of software code comes from us." VW estimates that only 10% of the software in its vehicles is developed in-house. https://spectrum.ieee.org/...
Deloitte estimates that >=40% of a vehicle's development budget can be attributed to systems integration, testing, verification and validation. [...] Unsurprisingly, efficiently managing variant complexity is a significant concern for the auto industry. https://spectrum.ieee.org/…
Code on wheels! Good read. “...as of 2020, Volvo has a superset of about 120 ECUs... they comprise a total of 100 Mn lines of code. This code contains 10 Mn conditional statements as well as 3 Mn functions, which are invoked some 30 Mn places in the code.” https://spectrum.ieee.o…
Interesting: “Run a job assessment with all top managers at VW, Audi, Porsche, BMW, and Daimler tomorrow and ask them to code [...] if they are not able to do so, fire them immediately, because they are not fit for the job.” Former head of Audi's R&D. https://spectrum.ieee.org/..…
Low-end vehicles contain 100M LOC, while high-end vehicles with advanced driver-assist systems may contain 150 electronic control units and 150M LOC. https://spectrum.ieee.org/...