The global automotive industry is entering one of the most transformative periods in its history. Electrification is accelerating, emissions regulations are tightening across major markets, and vehicles are rapidly evolving into software-defined platforms.

Yet beneath the headlines about electric vehicles (EVs), another transformation is quietly reshaping the automotive ecosystem: the evolution of vehicle diagnostics.

Rather than witnessing a simple transition from internal combustion engines (ICE) to electric propulsion, the industry is entering a dual-technology era in which advanced ICE vehicles and rapidly evolving EV architectures coexist. This reality is redefining the demands placed on technicians, workshops, and the diagnostic tools they rely on.

In this environment, diagnostics is no longer just a troubleshooting function. It is becoming a core infrastructure layer of modern automotive maintenance, enabling technicians to interpret the enormous volumes of data generated by today’s vehicles.

ICE Vehicles: Increasingly Digital Machines

Despite the rapid growth of electrification, ICE vehicles will remain a dominant part of the global fleet for years to come. According to the International Energy Agency, the global vehicle parc now exceeds 1.4 billion vehicles, and ICE and hybrid vehicles are expected to account for more than half of the global fleet well into the 2030s (IEA, 2024).

At the same time, combustion vehicles have evolved far beyond their mechanical origins.

In the early 1990s, a typical vehicle contained fewer than 10 electronic control units (ECUs). Today, modern passenger vehicles commonly include 70–150 ECUs, while high-end vehicles can exceed 200 control modules managing powertrain functions, safety systems, infotainment, and connectivity (McKinsey & Company, 2023).

These systems communicate through increasingly sophisticated in-vehicle networks such as CAN, LIN, FlexRay, and Automotive Ethernet, forming complex electronic architectures that must function seamlessly for the vehicle to operate safely.

Several forces are driving this surge in electronic complexity:

• stricter global emissions regulations, including Euro 6 and the upcoming Euro 7 standards
• widespread adoption of Advanced Driver Assistance Systems (ADAS)
• increasingly sophisticated engine and transmission management strategies
• connected infotainment, telematics, and over-the-air software platforms

ADAS technologies in particular have transformed service procedures. Radar sensors, cameras, and ultrasonic systems require precise calibration to operate correctly. Even routine repairs – such as replacing a windshield or repairing a bumper – can require advanced calibration procedures supported by professional diagnostic equipment.

At the same time, vehicles are generating unprecedented amounts of operational data. Connected cars can produce up to 25 gigabytes of data per hour from sensors and control systems. For technicians, this means traditional troubleshooting methods are no longer sufficient. Basic code readers cannot interpret encrypted gateways, cross-module interactions, or advanced communication protocols.

Professional diagnostic platforms must now support:

• deep multi-system scanning across dozens of ECUs
• real-time sensor and parameter analysis
• module coding and software updates
• secure access to manufacturer-protected systems

In short, modern ICE vehicles have become digital ecosystems on wheels, and maintaining them requires diagnostic tools capable of navigating increasingly complex electronic architectures.

EVs Introduce a New Diagnostic Paradigm

While ICE vehicles are becoming more electronically sophisticated, EVs introduce an entirely new diagnostic framework centered on high-voltage energy systems and battery management. EV adoption has accelerated rapidly. According to the International Energy Agency, global EV sales exceeded 14 million units in 2023, bringing the worldwide EV fleet to more than 40 million vehicles (IEA, 2024).

Unlike combustion vehicles, EV diagnostics focuses on monitoring electrical and electrochemical systems rather than combustion processes or emissions control.

Key EV subsystems requiring diagnostic oversight include:

• high-voltage lithium-ion battery packs
• Battery Management Systems (BMS)
• electric motor controllers and inverters
• onboard chargers and DC-DC converters
• battery thermal management systems

Most EV platforms operate on 400-volt architectures, while next-generation systems are increasingly adopting 800-volt platforms to enable faster charging and higher efficiency (Deloitte, 2023). Battery packs themselves are highly complex. A single EV battery can contain thousands of lithium-ion cells arranged in modules, each continuously monitored by the BMS to ensure safe operation and balanced performance.

EV diagnostics therefore, centers on indicators such as:

• State of Charge (SOC) – real-time energy availability
• State of Health (SOH) – long-term battery degradation
• cell voltage balancing
• thermal management performance

In addition, EV powertrains are heavily software-controlled. Many service issues arise not from hardware failure but from software calibration conflicts, firmware errors, or communication faults between control modules.

This shift reflects a broader transformation across the automotive industry. As McKinsey & Company notes: “The vehicle is rapidly becoming a software-defined platform, where functionality is increasingly determined by software rather than hardware.”

For workshops and technicians, this means diagnostics must increasingly integrate electrical system monitoring, battery analytics, and software management.

A Dual-Technology Aftermarket

The coexistence of increasingly sophisticated ICE vehicles and expanding EV fleets is reshaping the automotive aftermarket.

Rather than reducing demand for diagnostics, this technological diversity is accelerating it. According to MarketsandMarkets, the global automotive diagnostic scan tools market is projected to grow from roughly $37 billion in 2023 to more than $60 billion by 2030 (MarketsandMarkets, 2023).

This growth is driven by two simultaneous forces.

First, ICE vehicles continue to gain electronic complexity as manufacturers optimize performance, efficiency, and safety. Second, EV adoption is creating entirely new diagnostic requirements centered around battery health, high-voltage systems, and software control.

As a result, many industry observers now describe the aftermarket as entering a “Golden Age of Complexity.” For workshops, this means supporting a diverse fleet of vehicles built on fundamentally different propulsion technologies.

Supporting the Modern Workshop

For technicians and service centers, the challenge is not only technical but strategic.

As vehicle fleets diversify, workshops must decide whether to specialize in a particular technology or invest in tools capable of servicing a wide range of platforms. Diagnostic systems that support both ICE and EV architectures provide important operational flexibility, allowing service providers to adapt as the vehicle parc evolves.

In this environment, the most valuable diagnostic solutions will emphasize:

• broad coverage across global vehicle brands
• continuous software updates
• compatibility with emerging EV platforms
• advanced system-level data interpretation

As vehicles become more digital and electrified, diagnostics is evolving into the critical interface between technicians and increasingly complex automotive systems.

Diagnostics in the Era of Software-Defined Vehicles

The future of automotive diagnostics will not be defined by a single propulsion technology. Instead, it will be defined by data – and the ability to interpret that data accurately, efficiently, and safely.

Whether diagnosing a turbocharged combustion engine or assessing the electrochemical health of a lithium-ion battery pack, technicians rely on intelligent diagnostic systems to translate complex vehicle data into actionable insights.

As the automotive aftermarket enters this new era of technological convergence, companies like TOPDON that understand both dimensions of the industry – ICE refinement and EV expansion – will play a central role in enabling workshops to navigate the transition.

The road ahead may be electric, mechanical, or both. But diagnostics will remain the essential link connecting every vehicle to performance, safety, and long-term reliability.