TECHNICAL SERVICE BULLETIN: SUBSEQUENT REPAIR ACTION: FRONT MOTOR REDUCTION GEAR ASSEMBLY REPLACEMENT (SC345Z) - This bulletin provides information regarding grinding or whining noise coming from the front motor reduction gear assembly after replacing the oil under SC345 (published in August 2025) on certain 2023-2024MY Niro EV (SG2 EV) vehicles produced from December 12, 2022 through February 7, 2024 and EV6 (CV) vehicles produced from December 14, 2022 through February 22, 2024. In rare cases, the front motor reduction gear assembly may exhibit noise after having the oil replaced.
full bulletin at NHTSA ↗2024 Kia EV6 powertrain problems
moderate Owners of the 2024 Kia EV6 have filed 15 NHTSA complaints about the powertrain at roughly $2,500 to repair (U.S. federal records, as of July 2026). Source: NHTSA Office of Defects Investigation. See powertrain across all vehicles →
Complaints
15
Recalls
0
Avg fix
$2,500
| Model year | powertrain complaints |
|---|---|
| 2022 EV6 | 41 |
| 2023 EV6 | 24 |
| 2024 EV6 (this page) | 15 |
| 2025 EV6 | 12 |
What stands out
Powertrain accounts for 21% of all owner complaints filed against this vehicle, across 3 categories tracked.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering powertrain on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
VOLUNTARY SERVICE CAMPAIGN: OWNER NOTIFICATION (SC345) - This document is the owner notification advising that Kia is conducting a Voluntary Service Campaign to replace the gear oil in the front motor and gear reduction assembly, and fill it to the factory-specified amount in certain 2023-2024MY EV6 vehicles, manufactured from December 14, 2022 through February 22, 2024.
full bulletin at NHTSA ↗VOLUNTARY SERVICE CAMPAIGN: DEALER PRINCIPAL MEMO (SC345) - This document is the announcement to the dealer principals advising that Kia is conducting a Voluntary Service Campaign to replace the gear oil in the front motor and gear reduction assembly, and fill it to the factory-specified amount in certain 2023-2024MY EV6 vehicles, manufactured from December 14, 2022 through February 22, 2024 and Niro EV vehicles, manufactured from December 12, 2022 through February 7, 2024.
full bulletin at NHTSA ↗VOLUNTARY SERVICE CAMPAIGN: DEALER PARTS AND SERVICE MANAGER MEMO (SC345) - This document is the announcement to the dealer Parts and Service managers advising that Kia is conducting a Voluntary Service Campaign to replace the gear oil in the front motor and gear reduction assembly, and fill it to the factory-specified amount in certain 2023-2024MY EV6 vehicles, manufactured from December 14, 2022 through February 22, 2024 and Niro EV vehicles, manufactured from December 12, 2022 through February 7, 2024.
full bulletin at NHTSA ↗VOLUNTARY SERVICE CAMPAIGN: QUESTION AND ANSWER (SC345) - This document is the Question and Answer Guide containing the most frequently asked questions regarding the Voluntary Service Campaign SC.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
Owners report the ICCU (Integrated Charging Control Unit) suddenly fails without warning, causing complete loss of motive power and electrical shutdown. Vehicles become immobilized, unable to shift into gear or neutral, with doors that won't unlock and parking brakes that won't release—some have to be dragged onto flatbed trucks. Most failures happen during driving; warnings appear moments before shutdown ("Stop vehicle and check power supply," "Check electrical system"), and some owners experience severe limp mode (10–25 mph) before total loss of power.
The critical issue: Kia issued NHTSA Recall 24V-867 with a software update as the remedy, but multiple owners report failures occur weeks or months *after* that update was applied. One owner had the recall fix performed, then experienced another ICCU failure with diagnostic code P1A9096—the exact code the recall instructs dealers to monitor for.
Related failures include 12-volt batteries that fully deplete despite a full high-voltage battery, charging systems that won't work, and high-voltage batteries that degrade severely or fail entirely. One owner lost 35–40 cumulative days of use across four service visits; another faced up to 8 weeks without the vehicle.
Safety-critical incidents: stranding in sub-zero weather requiring multiple tow trucks, sudden power loss on 50 mph roads creating rear-end collision risk, and inability to escape or signal for help when power dies. Owners describe these as life-threatening situations, particularly in winter or on busy highways.
Same Kia EV6 powertrain reports on nearby years: 2022 · 2023 · 2025
Failure modes owners describe
ICCU failure causing loss of motive power and electrical shutdown
The Integrated Charging Control Unit (ICCU) fails suddenly during driving or at rest, resulting in complete or near-complete loss of electrical power, immobilization, and inability to shift into gear or neutral. Multiple owners report the vehicle becomes unresponsive and non-towable without specialized equipment. Some failures occur weeks or months after the recall remedy (software update) was applied.
When: Various mileage and timing: one vehicle at ~10,000 miles; another within weeks of prior high-voltage battery replacement; one after approximately three months post-recall remedy; one at less than 400 miles on new vehicle; others at unspecified but low mileages.
Symptoms owners cite: Complete loss of electrical power and motive power; Vehicle immobilized, unable to shift into neutral or park; Multiple dashboard warnings: 'Check electric vehicle system', 'Stop vehicle and check power supply', 'Check electrical system failure'; Electronic parking brake engages and cannot be released; Doors electronically unlock-able, steering wheel cannot turn; Vehicle enters severe limp mode (speed reduced to 10–25 mph) before complete shutdown; Popping or explosive sound from rear of vehicle or under the car; Loss of cabin heat and climate control; High-voltage and low-voltage electrical systems unresponsive
Codes mentioned: P1A9096
Repairs/costs cited: Kia dealers have replaced the ICCU unit and high-voltage fuse; however, some owners report failure recurs after replacement or after initial firmware-only update. Parts availability delays repair by 2–4 months in some cases. One owner reports being without vehicle for 8 weeks; another for 27 consecutive days on a single visit, with cumulative out-of-service time of 35–40 days across multiple visits.
Recalls/TSBs owners mention: NHTSA Recall 24V-867 / Kia campaign SC327 issued for ICCU defect; remedy is a firmware/operational logic software update. Multiple owners confirm recall was applied but defect persisted. No evidence in narratives of hardware redesign, extended warranty, or root-cause identification by Kia. One owner notes Kia required approval before repairing a 'front inverter' failure.
12-volt battery premature depletion and failure
The 12-volt battery becomes fully depleted despite the high-voltage traction battery being at or near full charge. This occurs in the context of ICCU malfunction; owners and dealers identify it as a downstream symptom of ICCU failure. One battery failed at less than 18 months into service on a CPO vehicle with ~23,000 miles; another failed on a vehicle with only ~10,000 miles approximately three months after ICCU replacement.
When: Less than 18 months into service on CPO vehicle (~23,000 miles); approximately three months after ICCU replacement on another vehicle; shortly after initial software update intended to correct 12-volt charging issues.
Symptoms owners cite: 12-volt battery warning lights ('12-volt battery low', 'Power limited'); Complete depletion of 12-volt battery; Loss of low-voltage electrical power: unable to unlock doors electronically, start engine, or shift into gear; Vehicle immobilized
Repairs/costs cited: 12-volt battery replaced under warranty. One owner reports temporary jump-start via portable battery pack, but vehicle would not stay powered long enough to shift into neutral or activate tow mode. Some dealers have applied firmware updates without addressing underlying ICCU condition; subsequent 12-volt failures occurred despite the software update.
Recalls/TSBs owners mention: Software/firmware update issued to correct 12-volt charging issue; owners report this did not prevent subsequent 12-volt battery failure. Warranty coverage applied in cases where replacement was performed.
Charging system failure and charging port malfunction
Vehicle charging system becomes inoperative; charging begins briefly then stops. One owner reported this approximately one month after ICCU and high-voltage fuse replacement, diagnosed as charging port failure. This may be secondary to ICCU failure or independent; narratives do not clearly distinguish.
When: Approximately one month after ICCU and high-voltage fuse replacement.
Symptoms owners cite: Vehicle charges briefly then stops; 'Check electrical/hybrid system' warning light while driving; Vehicle cannot accept charge at charging station
Repairs/costs cited: Diagnosed as charging port failure; specific repair cost and replacement details not provided in narrative. Vehicle was out of service 27 consecutive days for this repair.
High-voltage battery failure and severe range degradation
High-voltage traction battery fails or degrades severely, resulting in sudden loss of range and inability to charge. One owner reports battery dropped from 40 miles displayed range to 5 miles before total failure; another had entire high-voltage battery pack replaced due to severe range degradation, followed by recurrence of major electrical failure weeks later.
When: One vehicle reported range loss at unspecified mileage; another required high-voltage battery replacement, with second major electrical failure occurring weeks after that replacement.
Symptoms owners cite: Sudden, dramatic loss of remaining range (40 miles to 5 miles); Severe range degradation over time despite full charging; Vehicle becomes unresponsive and will not charge; Vehicle cannot be shifted into neutral or powered on
Repairs/costs cited: One owner reports entire high-voltage battery pack was replaced; parts availability could delay repair by 2–4 months. Replacement was not yet complete at time of narrative submission; owner was without vehicle for uncertain extended period.
Synthesized from 15 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 2 most recent
ICCU failed. Heard a popping sound from rear of passenger compartment, dash errors lit up, car went to limp mode
Description of Incident: 1. What component or system failed or malfunctioned, and is it available for inspection upon request? The high-voltage battery system and charging system in my 2024 Kia EV6 malfunctioned. Despite showing 40 miles of range remaining, the battery suddenly dropped to 5 miles before the car became completely unresponsive and failed to charge. Additionally, the vehicle could…
Had powertrain trouble with your 2024 Kia EV6?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the powertrain problem on the 2024 Kia EV6?
It's a documented issue but not catastrophic. 15 complaints have been filed. Repairs average $2,500 and most owners catch it before it causes a breakdown.
At what mileage does the powertrain typically fail?
Mileage data is limited for this issue. Owners report failures across a wide range, suggesting cause is more about driving conditions and maintenance than mileage alone.
What does it cost to fix?
Independent shops typically charge around $2,500 for powertrain repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to powertrain?
No active recalls currently cover powertrain issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2024/Kia/EV6.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.