UK Buyer Reliability Guide3 Known Faults Documented

Hyundai Ioniq 5 Common Problems & Reliability

A retro-futrinsic EV on the E-GMP platform. Highly acclaimed, but early cars have been defined by ICCU (Integrated Charging Control Unit) hardware failures and 12V battery management bugs common to the platform.

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Generation Periods
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Known Issues
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Critical Faults
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Moderate Issues

Select a Model Year Period

Detailed fault breakdown, symptoms, and estimated repair bills by production year.

Most Common Hyundai Ioniq 5 Faults & Repair Costs

High Risk

ICCU Failure (Integrated Charging Control Unit)

Est. Cost£0 (Recall/Warranty)

The ICCU handles 12V charging from the high-voltage battery. Internal MOSFETs can fail due to overvoltage spikes, often blowing an internal 40A fuse and causing a total loss of 12V replenishment while driving.

Warning Signs:

"Check electric vehicle system" warning, Audible "pop" followed by "Stop vehicle and check power supply", 12V battery dies repeatedly, Turtle mode

What to Check Before Buying:
  • Service campaign status for ICCU (TSB 24-01-086H)
  • Scan for DTC P1A9096 (DC-DC Converter Error)
Verified by IsItAGoodCar Research Team
Moderate Risk

12V Battery Logic & "Orange Light" Confusion

Est. Cost£0 (Software update)

The amber dashboard light indicates 12V charging. Logic bugs in early software would stop 12V maintenance if the HV battery dropped below 20%, leading to "bricked" cars even if the HV battery had plenty of charge for systems.

Warning Signs:

12V battery flat despite HV battery being at 20-30%, Car fails to enter "Ready" mode

What to Check Before Buying:
  • Confirm BMS and VCU software are at the latest revisions
Verified by IsItAGoodCar Research Team
Moderate Risk

Steering Column Knock/Clunk

Est. Cost£0 (Warranty)

A known issue where a bearing in the steering column or a friction point in the roll connector causes a knock or clicking sound when turning.

Warning Signs:

Clunk felt through wheel at low speed, Clicking when rotating steering wheel

What to Check Before Buying:
  • Manoeuvre at low speed
  • Check for TSB 22-ST-005H/008H compliance
Verified by IsItAGoodCar Research Team
Essential Pre-Purchase Step

Buying a used Hyundai Ioniq 5? Always check for hidden finance and write-off history.

Mechanical problems are only half the battle. Over 1 in 3 UK used cars checked have unpaid finance or accident write-off records that could cause you to lose the car or thousands in value.

Inspection Checklist for Hyundai Ioniq 5 Buyers

CRITICAL: Verify Recall 272 (ICCU) has been performed; this includes a software update and potential ICCU/fuse replacement.
Check for the "Stop vehicle and check power supply" warning history, as this indicates a near-total 12V depletion.
Listen for a "clunk" or "knock" through the steering wheel at low speeds or when parking.
Ask if third-party apps (e.g., Optiwatt) have been used, as these can trigger 12V drain by repeatedly waking the car.