Editorial: EV diagnostic process should become industry standard

A standard electric vehicle diagnostic process is critical to identification and quick resolution of EV issues. The country should follow California's lead in establishing a uniform approach.

The California Air Resources Board is adopting a set of EV diagnostic requirements to add transparency and consistency as the state phases out sales of new internal combustion engine vehicles by 2035. The requirements are designed to put EV and combustion vehicle diagnostics on a level playing field, ensuring EVs are as repairable as gasoline vehicles.

The information will be similar to that gleaned through onboard diagnostic system II ports in gasoline vehicles — a data-pull that has been an industry norm since the 1990s.

Starting with the 2026 model year, EV requirements will show drivers the battery's state of health and charging speed and ensure independent shops can access the same repair information as franchised dealerships.

The rules are part of CARB's Advanced Clean Cars II regulation, which says zero-emission vehicles and plug-in hybrids must make up all of California's new-vehicle sales by the 2035 model year. At least eight other states have adopted the Advanced Clean Cars II program.

Without the CARB requirements, EVs do not have standard onboard diagnostic monitoring or data requirements largely because they have no tailpipe emissions. Onboard diagnostic system II ports monitor combustion engine vehicles' emissions, among other things.

The requirements will give EV drivers crucial battery health data and will be especially helpful to managers of EV fleets who gather information about their vehicles.

Lacking a uniform approach, the industry risks repeating the challenges mechanics faced when diagnosing combustion engine vehicles ahead of the standardization of the onboard diagnostic system II port in the 1990s.

So much of the EV sector is evolving. Range, battery chemistry, charging speed and infrastructure are developing quickly, but the ownership experience still has shortcomings.

Consumers are already trying to keep up with EV advancements to make the best purchase choice. Fixing the vehicle shouldn't be another factor that makes them pause. Regulators and automakers should follow CARB to ensure EV diagnostics are as clear-cut as diagnosing a gasoline engine vehicle.