2022 Hyundai Ioniq 5: What to check before buying

Sudden loss of drive power is the main failure. Most cases trace to the Integrated Charging Control Unit (ICCU) and its high-voltage fuse. Drivers often hear a pop and see "Check electric vehicle system," then "Stop vehicle and check power supply." Speed drops to around 20 to 25 mph and the car shuts down. The 12V battery drains and home charging stops. Failures show up from about 7,300 to 24,700 miles, including after the Service Campaign 997 software update. Repairs often stall for weeks on back-ordered parts. Two crash reports say the car would not stop under braking.

Propulsion cuts out while driving, and ICCU failures cause most of it. Some happen at highway speed in heavy traffic. Warnings such as "Check electrical system" or "12V battery voltage low" come first, then the car slows to a crawl or dies. Repeat ICCU and 12V battery replacements and long waits for parts are common. Reported mileages run from 9,300 to 49,000. Other reports describe brief power cuts, a phantom "Emergency Braking" message, and one failed EV battery. In one crash report, the car moved on its own into a garage after the shifter failed.

These reports cover two problems. ICCU failures put the car in limp mode at about 25 to 30 mph and show "Stop vehicle and check power supply." The car then cannot charge. Some units have been replaced twice, and parts can take months. Separately, Level 2 home charging stops partway, especially on warm days above 32 amps or around 9kw, and the charge port runs hot. Owners say the service bulletin fix only lowers charging speed. One report describes speed suddenly capped at 20 mph.

Most of these reports are ICCU and high-voltage fuse failures, not steering faults. The car shows warnings such as "Stop Vehicle Check Power Supply" or "12v Battery Critical," slows, and shuts down. In some cases the wheels lock and the hazard lights will not work. Steering can feel unassisted afterward. Some owners report a second ICCU failure after a warranty repair. Other complaints describe a shift knob that sticks out or falls off, lane assist grabbing the wheel during power surges, and the car pulling right on the freeway.

Brake lights stay off in i-Pedal or one-pedal driving unless the accelerator is fully released. The car can slow sharply, to about 5 mph or a full stop, with no signal to drivers behind. Owners describe tailgaters braking hard. They say it happens at all speeds and has since delivery, with no warning lights, so it appears to be normal behavior rather than a fault. One other complaint says the headlight on one side turns off when the turn signal is on.

Acceleration cuts out, or the car slows without warning, on the highway. Smart cruise control and the forward safety system shut off at speed, and the accelerator stops responding at 70 to 75 mph, so drivers have to coast to the shoulder. Restarting the car often clears it, and dealers find nothing wrong. Other reports describe the car putting itself in park, weaker ECO-mode acceleration after a recall repair, and driver-assist settings wiped by a Bluelink outage. In one crash, a parked car rolled away after the shifter control unit failed.

Unintended rolling is the main concern. After stopping on a slight incline, the car rolls backward unless the driver presses harder on the brake. In one serious report, a parked, switched-off car rolled backward and pinned a person in a snowbank. Others report collision warning and automatic braking not activating in stop-and-go traffic, a "Stop vehicle and check brake system" error with limp mode, and strong regenerative slowing while the accelerator is still pressed. Dealers often find nothing wrong.

Parked cars roll away when left in Park without the parking brake set. One car rolled backward on a slight incline after being shut off, and it rolled again whenever the brake pedal was released. Another rolled away in a parking garage and hit a wall at about 700 miles. That owner had received notice of recall campaign 22V324000 for the parking brake. Neither report includes a dealer diagnosis or repair.

Automatic braking both fires falsely and fails to fire. The system brakes hard under overpasses and road signs, or cruise control shuts off with a radar-blocked message and the car slows fast, nearly causing rear-end collisions. Two crash reports describe forward collision warning and auto braking not activating, and ABS or all-wheel drive seeming not to work. One dealer found a front radar alignment failure and would not cover it under warranty. Another report links lasting ABS and Smart Cruise Control warnings to an ICCU problem.