Historically, vehicles were built around electronic control units (ECUs), small computers dedicated to specific functions such as braking, steering, infotainment, or climate control. Each ECU was tied to custom hardware, meaning adding a new feature often required physically adding another ECU and rewiring parts of the vehicle.
The approach worked when vehicles had a handful of electronics, but today’s electric vehicles (EVs) can carry well over 100 ECUs, leading to heavy wiring harnesses, higher costs, and limited flexibility. Not surprisingly, this hardware-centric approach is quickly becoming outdated, and software is taking its place. The software-defined vehicle (SDV) is offering centralized computing platforms that are faster and more streamlined.
Unlike ECUs locked to a single function, SDVs consolidate multiple capabilities into powerful central computers that run multiple applications on shared hardware. Instead of producing an EV with fixed hardware-defined features, automakers can now introduce new capabilities through over-the-air (OTA) updates, much like adding apps or upgrading the operating system on a smartphone. (Figure 1)
Figure 1. Software-defined vehicles consolidate hardware, connectivity, and applications into a centralized platform, enabling continuous updates and new capabilities over the vehicle’s lifespan.
OTA updates are wireless software downloads that allow automakers to add features, improve performance, or fix issues without a service visit. The result is a car that can be updated and improved continuously, enabling faster innovation, reduced complexity, and entirely new ways to enhance performance and safety.
Why is software the answer?
EVs demand far more complex electrical architectures than conventional vehicles, with high-voltage battery management at the core. Managing such intricacy with hardware alone is costly, rigid, and difficult to scale.
Industry data reflects this shift: “The electric segment leads the SDV market — estimated at 45.3% in 2025 — because EVs inherently require sophisticated software platforms for battery management, regenerative braking, energy efficiency, and performance tuning,” according to a recent report from Coherent Market Insights.
Software-defined platforms offer a more adaptable approach, reducing weight, streamlining design, and unlocking continuous improvements that keep EVs efficient and competitive over their entire lifespan.
This shift is being accelerated by several key factors:
- Reduced hardware and wiring complexity: Modern EVs can contain more than 100 ECUs, each with a dedicated harness. Consolidating those into fewer, high-performance domain or zonal controllers cuts hundreds of pounds of copper wiring, reduces connectors (a common failure point), and lowers material and assembly costs. Less wiring also frees space for battery cells and improves serviceability.
- Faster feature deployment: Over-the-air (OTA) updates let engineers push new battery charging algorithms, motor control strategies, or safety features directly to the vehicle. Instead of waiting for a hardware redesign, automakers can optimize thermal management, expand fast-charging profiles, or add driver-assistance refinements through software alone. This reduces warranty costs and opens new revenue streams through post-sale upgrades and subscriptions.
- Longer vehicle lifespans: Hardware-defined designs are fixed at production, but SDVs can be continuously upgraded. This extends the functional life of a vehicle, keeps pace with evolving standards (like cybersecurity or charging protocols), and sustains resale value. Ultimately, that makes EVs more attractive to buyers concerned about depreciation and improves total cost of ownership.
- Improved system integration: Centralized software platforms allow subsystems, such as braking, steering, and power distribution, to share data in real time. Instead of each ECU operating in isolation, consolidated controllers enable tighter coordination across the vehicle, which improves efficiency, reduces redundancy in sensors and processors, and opens the door to advanced functions like predictive maintenance and automated driving.
What are examples of hardware functions now shifting to software?
Battery management is one of the clearest areas where hardware has given way to software. In earlier designs, charging profiles, thermal regulation, and fault detection were each tied to separate circuits or controllers, adding weight and limiting flexibility. Centralized software platforms now manage all three dynamically, allowing the vehicle to optimize performance in real time and adapt across different use cases.
Tesla has taken this approach with OTA updates that modify how the battery charges in cold weather. By improving preconditioning routines and adjusting charging curves, the updates help the pack reach optimal temperature more efficiently before Supercharging. This reduces lithium plating and degradation, shortens charging times, and improves winter driving range without swapping or redesigning any hardware.
Thermal management is similarly shifting to software control. Instead of relying on fixed mechanical controllers, modern EVs use domain software to coordinate coolant pumps, fans, and heat pumps across the vehicle. This integration lets waste heat from motors, inverters, and batteries be redirected for cabin heating, reducing the need for resistive heaters and preserving driving range in cold climates.
For example, GM’s Ultium Energy Recovery system uses software to manage a heat pump, which captures waste heat from batteries, motors, and power electronics, improving cold-weather performance and efficiency across different vehicle classes. The same Ultium architecture supports vehicles ranging from compact EVs to full-size trucks, showing how a single hardware platform can be adapted through software controls. (Figure 2)
Figure 2. GM’s Ultium Energy Recovery system uses software to manage heat pumps, warming the battery before charging to improve efficiency and reduce charging times. (Image: GM)
Additionally, several models from BMW (including the iX and i4) include advanced heat-pump systems paired with software that manages multiple thermal loops. These systems coordinate coolant flow, fan speed, and compressor behavior to make climate control, battery warming, and motor cooling work together more efficiently. The software manages transitions between different operating modes depending on ambient temperature and vehicle load, reducing energy waste and improving cold-weather performance.
Power distribution is also increasingly managed through solid-state fuses and software-driven switches. Instead of relying on mechanical relays, software can prioritize which systems draw power in real time. For example, an EV might temporarily reduce HVAC load when the driver demands peak acceleration, extending range while protecting the battery from heavy discharge.
Onsemi’s portfolio of intelligent power switches and SiC-based solid-state fuses shows how circuit protection is becoming programmable and adaptive. Unlike traditional blade fuses that operate once and must be replaced, these devices can be configured via software to adjust trip thresholds, reset after a fault, and report diagnostic data back to the central controller. That diagnostic visibility allows engineers to monitor the health of individual circuits, predict failures before they occur, and optimize energy distribution dynamically.
In a software-defined vehicle, this adaptability means a single hardware device can serve multiple roles across platforms, reducing part count and enabling OTA updates to refine protection strategies over the vehicle’s life. For instance, as battery chemistries evolve or charging standards shift, software updates can re-tune fuse parameters without redesigning the electrical architecture. It also enables smarter load-shedding strategies in extreme conditions, where the vehicle can automatically shut down non-critical accessories to preserve range or protect the battery.
Advanced driver-assistance systems (ADAS) also demonstrate the software shift. Features such as adaptive cruise control or lane keeping were once enabled by independent modules with limited communication. Sensor data from radar, lidar, and cameras is now typically fused in software, enabling more reliable functions and supporting the progression toward higher levels of autonomy.
For example, Rivian’s Gen 2 R1 models combine data from 11 cameras and five radars in real time through sensor fusion, enabling hands-free highway driving delivered via software updates. GM’s Super Cruise system takes a similar approach, using lidar-based maps and sensor fusion managed in software to support hands-free driving on highways.
Tesla helped popularize the idea that vehicles could gain new capabilities through software long after delivery, from entertainment and navigation features to performance improvements pushed via OTA updates. This shift demonstrated the potential of the digital cockpit as more than a static interface.
However, infotainment technology is now advancing even faster into the software-defined world, partly because it’s not safety-critical in the same way as braking, steering, or battery management. For EVs, moving cockpit functions into software reduces cost and weight while keeping the cabin experience current across the long lifespan of the vehicle. What once referred mainly to media and navigation has become the central interface for vehicle control.
Figure 3. Software-defined platforms, such as BMW’s iDrive 8 system in the iX, allow drivers to configure safety features like collision warnings directly through centralized digital controls. (Image: BMW)
Modern platforms such as BMW’s iDrive 8 allow illustrate this expansion, allowing drivers to configure safety features, collision warnings, and driver-assistance settings directly through the digital cockpit. Infotainment is extending far beyond entertainment and becoming a critical integration point for vehicle functions. (Figure 3)
Update challenges
Over-the-air updates are transforming vehicles into evolving platforms, but making this process reliable is a significant engineering challenge. Modern EVs contain many interdependent domains that must continue to function safely while new software is introduced. (Figure 4)
One challenge is system complexity. An update rarely affects a single function in isolation; software in one controller can alter interactions with braking, thermal management, or infotainment. Engineers must anticipate these dependencies and validate that changes in one domain do not cascade into others.
Another area is functional safety. Even small changes in torque control or charging profiles require assurance that critical functions behave as intended under all conditions. Validation against ISO 26262 and other standards is essential, and many teams are now turning to simulation, model-based design, and hardware-in-the-loop testing to accelerate this process without compromising rigor.
Figure 4. Over-the-air updates allow EVs to receive new features, performance improvements, and security patches wirelessly, extending functionality well beyond the initial production cycle.
Scale adds further complexity. Vehicles differ by model year, hardware revision, and regional requirements, which means updates must account for a wide variety of configurations. Staged rollouts, differential updates, and fallback strategies are now standard practices to keep fleets consistent while preserving vehicle availability.
Lifecycle planning is equally important. Ideally, vehicles should be designed to remain in service for a decade or more, long after suppliers, operating systems, or communication protocols may have changed. Update strategies must anticipate long-term maintainability from the early development stages.
Cybersecurity is intertwined with all of these challenges.
Every update, connected service, or data exchange represents a potential attack surface, and engineers must protect the update pipeline and the vehicle. Secure boot, encryption, and authentication ensure only trusted code is installed, while intrusion detection and continuous monitoring add another layer of defense.
Compliance frameworks, such as ISO/SAE 21434 and UNECE WP.29 provide important baselines, but engineers also need to plan for long-term patching, supply chain security, and cryptographic agility so protection lasts across the full service life of the vehicle.
As EVs connect more closely with charging infrastructure, protecting vehicle software becomes not only a safety issue but also an energy-system concern. Long-term patching and supply-chain security are necessary to maintain trust throughout the lifespan of the vehicle.
What does this shift mean for EV engineers?
The shift from hardware-defined vehicles to software-defined platforms is reshaping automotive engineering. For EVs, the impact is especially pronounced: software reduces wiring weight, enables continuous performance improvements, and keeps vehicles competitive across their lifespan. At the same time, it demands new expertise in system integration, thermal and power management, and cyber-resilience.
For engineers, the move to SDVs means focusing less on isolated hardware modules and more on holistic vehicle architecture. Instead of designing individual ECUs for fixed functions, it’s essential to now need to think in terms of domain controllers, shared compute resources, and software layers that can be updated over time.
This demands new skill sets in systems integration, model-based design, and validation of complex interactions across subsystems. Continuous deployment models (common in consumer tech) are also entering the automotive world, requiring engineers to plan for vehicles that evolve long after production.=
As GMI Insights notes, “Software-defined vehicles are increasingly equipped with advanced safety features powered by sophisticated software. These include real-time vehicle performance monitoring, advanced driver assistance systems (ADAS), such as lane-keeping assist, emergency braking, collision detection, and other proactive safety mechanisms.”
Ultimately, designing EVs in the software-defined era means building platforms that can adapt to changing requirements, absorb new functionality, and remain secure throughout their lifespan. This shift is redefining not only how vehicles are engineered, but also how they compete in a rapidly evolving market.
References
- Software Defined Vehicle Market Analysis, Coherent Market Insights (2025) — Coherent Market Insights
- Software Defined Vehicle Market Size Report, Global Market Insights (2025) — Global Market Insights
- Tesla Software Updates: Improving Cold Weather Charging Performance, Tesla Support — Teslarati
- Ultium Energy Recovery System in GM EVs, GM Pressroom — GM
- BMW iDrive 8: Digital Platform and Thermal Efficiency in EVs, BMW Group — BMW
- Introducing Rivian Gen 2 R1: Advanced Sensor Fusion and ADAS, Rivian — Rivian
- Intelligent Power Switches for EV Platforms, Onsemi — Onsemi
Filed Under: FAQs, Software