P1A90 on Genesis
DC/DC Converter Input Voltage Sensor Fault (ICCU)
P1A90 on Genesis vehicles indicates dc/dc converter input voltage sensor fault (iccu). Au7o has documented this code across 1 Genesis model — most commonly on GV70. 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.
Common Causes of P1A90
- •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- •Outdated ICCU control software (addressed by manufacturer software update)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
P1A90 on Genesis by Model
Genesis GV70(1 issue)
- ICCU Failure Causing Loss of Drive Power (Electrified GV70)2023-2025
The Integrated Charging Control Unit (ICCU) manages charging of the high-voltage pack and the 12V battery that runs accessories and control modules. The ICCU (and its internal fuse) can become damaged and stop charging the 12V system. The car then enters a fail-safe mode with warning lights, audible alerts, and reduced power; if driving continues it can fully lose drive power, sometimes preceded by an audible 'pop.' Drivers typically have ~22-45 minutes to pull over, with steering and brakes still functional. Genesis covered this under recalls tied to NHTSA 24V-204, expanded/replaced by Genesis 025G (Dec 2024), part of the broad Hyundai/Kia/Genesis ICCU campaign. The failed ICCU also produces dead-12V 'bricked' no-start events.
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View P1A90 across all makes →Frequently Asked Questions
What does P1A90 mean on 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 specifically, this code is documented across 1 model.
What causes P1A90 on Genesis vehicles?▼
Common causes on Genesis: 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. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P1A90 on a Genesis?▼
Repair costs vary widely depending on the root cause and specific Genesis model.
Which Genesis models have P1A90 documented?▼
Au7o has documented P1A90 on 1 Genesis model: GV70.