P1A90 on Genesis: How to Diagnose & Fix
DC/DC Converter Input Voltage Sensor Fault (ICCU)
1 Genesis model · 1 documented issue · 1 critical
P1A90 on Genesis by model: symptoms, diagnosis and fix
The Integrated Charging Control Unit (ICCU) charges the 12-volt battery. Certain electrical loads can make its internal MOSFET fail and open the ICCU fuse, so the 12V battery stops charging. The car then enters a fail-safe mode with warnings; if it is driven until the 12V battery is depleted, it loses all motive power. Certain 2023-2025 Electrified GV70 built at Hyundai Motor Manufacturing Alabama January 25, 2023 to November 9, 2024 (Genesis 025G). It includes 2023-2024 Electrified GV70s previously involved in Genesis recall 021G. Gasoline GV70s are not included. Eligibility is by VIN.
How to Fix
Have a Genesis retailer check the VIN for recall 24V868 (025G). The retailer updates the ICCU software and replaces the ICCU and its fuse if necessary, free of charge. Genesis has also extended coverage for ICCU and ICCU-fuse replacement on 2023-2025 Electrified GV70 to 15 years or 180,000 miles from original delivery (extension Z06G). Per the report, warning lights, a chime, on-screen messages and reduced power may appear over roughly 20-40 minutes of fail-safe driving. Observe the vehicle warnings and stop safely if drive power is reduced. Do not rely on an illustrated countdown or keep driving to exhaust a stated warning interval. High-voltage work requires an EV-qualified retailer.
Sources for this issue (3)
- Hyundai Part 573 report 24V-868 (Hyundai 272 / Genesis 025G), December 17, 2024 amendmentrecall
- Genesis extended warranty notification Z06G (ICCU and ICCU fuse, 15 years/180,000 miles)manufacturer
- Genesis service campaign 907G retailer best practice (TSB 23-01-069G-1), ICCU inspection for DTC P1A9096tsb
P1A90 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P1A90 mean on a Genesis?
P1A90 stands for "DC/DC Converter Input Voltage Sensor Fault (ICCU)." Stored by the Integrated Charging Control Unit, which bundles the on-board charger, DC-DC converter, and vehicle-to-load export hardware into one box. The module reports an implausible or out-of-range input-voltage sensor reading on the DC-DC converter stage, meaning the ICCU can no longer reliably step the high-voltage pack down to charge the 12-volt battery. Hyundai/Kia/Genesis service documentation carries it as the sub-coded fault P1A9096 in the ICCU inspection, fuse-replacement, and software-update campaign. Once the ICCU stops feeding 12 volts, the 12V battery drains and the vehicle progressively loses accessories, then drive power. On Genesis it is documented across 1 model: GV70.
What are the most common causes of P1A90?
The most common causes of P1A90 are: ICCU internal failure (DC-DC converter stage) on E-GMP platform vehicles, Blown ICCU input fuse following an ICCU fault event, Outdated ICCU control software (addressed by manufacturer software update), 12-volt battery repeatedly deep-discharged by a failing ICCU. The specific cause varies by vehicle.
How much does it cost to fix P1A90 on a Genesis?
Repair costs vary widely with the root cause and Genesis model; each issue on this page carries its own estimate where one is published.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.