Hyundai Ioniq 5 and Kia EV6: E-GMP diagnostics for owners

The Ioniq 5 and EV6 share E-GMP, a dedicated electric platform with an 800 V architecture that enables very fast charging.

Related: OBD on electric vehicles, what it gives.

Why generic OBD-II gives so little

OBD-II is an emissions standard. Its mandated content is combustion data: misfires, fuel trims, oxygen sensors, catalyst efficiency, EVAP integrity.

An electric vehicle has none of it, so there is nothing for the standard to require.

Everything that matters here — traction battery state of health, cell voltages, inverter data, thermal management, charging diagnostics — is manufacturer-specific.

Scan tool limits: what OBD cannot see and electric vehicle OBD battery diagnostics.

The 12 V battery, again

The most common immobilising failure on any electric vehicle, and it surprises people every time.

The 12 V system powers the contactors and control modules that decide whether to connect the traction battery at all. Flat 12 V means a car that does nothing, regardless of a full traction battery.

This is readable with a standard adapter, and it is the most valuable owner-side check available.

EV 12V battery failures and P0560 to P0563 system voltage faults.

Note: these vehicles use a lithium 12 V battery on some variants, with a different failure profile from lead-acid, and some have a utility-mode button that recharges it from the traction battery. Find out what yours has.

The 800 V architecture

The distinguishing feature, and it has practical consequences.

Very fast charging on a compatible charger — among the fastest available.

On a 400 V charger, the vehicle uses its motor and inverter to boost the voltage. That works, and it means charging behaviour differs noticeably between charger types.

Charging speed depends heavily on battery temperature, which is why preconditioning before a fast charge makes a substantial difference — and why a car that charges slowly may simply be cold rather than faulty.

Assessing battery health

The number that determines a used example’s value.

Generic OBD-II will not give it to you. What you can do:

• Charge to 100% and compare indicated range against the original figure.
• Watch the charging curve at a fast charger — how quickly the rate tapers.
• Measure consumption over a known route in known conditions.
• Ask for a manufacturer battery health report.

Used EV buying, battery health check and hybrid battery state of health monitoring.

Euro 7 introduces battery durability reporting, which should make this considerably more transparent: Euro 7 and on-board monitoring.

Vehicle-to-load

Both models can supply mains power from the traction battery, which is genuinely useful and worth testing on a used purchase — it is a feature people assume works and rarely check.

Everything mechanical is conventional

And no scan tool diagnoses any of it.

• Tyres wear faster — weight and instant torque, in EV-specific sizes that are not cheap: tyre rotation and wear patterns and inner edge tyre wear.
• Brakes corrode rather than wear, because regeneration does most of the slowing. Seized calipers from disuse are the common finding: grinding when braking and clunk when braking.
• Suspension carries more weight: suspension bushes wear symptoms.
• Vibration diagnosis is identical to any car: car shakes at motorway speed.

Software and updates

Both models receive over-the-air updates, which changes the diagnostic picture: behaviour can alter overnight, and a fault present last week may be resolved without a workshop visit.

OTA firmware updates and diagnostics and UN R155 and R156 vehicle cybersecurity.

Establish the software version and update history on a used example.

Buying used

1. Indicated range at 100% against the original specification.
2. Charging curve at a fast charger, from a warm battery.
3. Ask for a manufacturer battery health report.
4. 12 V battery age and type.
5. Brakes, specifically for corrosion.
6. Tyres, which wear faster and cost more.
7. Software version and update history.
8. Test vehicle-to-load if the feature matters to you.

The practical next step: pair an ELM327 adapter, open the free tier of the app and check 12 V system voltage. On an electric car, that is the reading most likely to strand you and the one generic diagnostics handles best.