TECHNICAL SERVICE BULLETIN: TRANSMISSION FLUID APPLICATION GUIDE - This bulletin has been revised to include additional information. New/revised sections of this bulletin are indicated by a black bar in the margin area. This bulletin provides information relating to the correct transmission fluid type and fill quantity requirement for each Kia model. A flush is required ONLY when a transmission is replaced, and the transmission oil cooler is transferred to the new transmission.
full bulletin at NHTSA ↗2021 Kia Forte powertrain problems
moderate Owners of the 2021 Kia Forte have filed 7 NHTSA complaints about the powertrain at roughly $2,500 to repair (U.S. federal records, as of August 2026). Source: NHTSA Office of Defects Investigation. See powertrain across all vehicles →
Complaints
7
Recalls
0
Avg fix
$2,500
| Model year | powertrain complaints |
|---|---|
| 2017 Forte | 11 |
| 2018 Forte | 8 |
| 2019 Forte | 46 |
| 2020 Forte | 15 |
| 2021 Forte (this page) | 7 |
| 2023 Forte | 7 |
| 2024 Forte | 3 |
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.
TECHNICAL SERVICE BULLETIN: IVT OIL PRESSURE SENSOR REPLACEMENT: This bulletin provides information to replace the Intelligent Variable Transmission (IVT) Oil Pressure Sensor (OPS) on some 2018-2024MY vehicles listed on page 3 equipped with IVT. The affected vehicles may exhibit a malfunction indicator lamp (MIL) illuminated on the instrument cluster with DTCs P084500, P084600, and/or P0867XX present with no drivability concerns due to a failed IVT oil pressure sensor.
full bulletin at NHTSA ↗This bulletin provides information relating to the correct transmission fluid type and fill quantity requirement for each Kia model. A flush is required ONLY when a transmission is replaced.
full bulletin at NHTSA ↗TECHNICAL SERVICE BULLETIN: IVT SOFTWARE LOGIC IMPROVEMENT AND/OR IVT REPLACEMENT - This bulletin provides the procedure to update the Transmission Control Module (TCM) software logic and, if necessary, replace the Intelligent Variable Transmission (IVT) assembly on certain 2019-2021MY model vehicles listed in the chart below, which may exhibit an MIL ON with the DTC(s) listed below and a lack/delay in acceleration due to transmission slippage.
full bulletin at NHTSA ↗TECHNICAL SERVICE BULLETIN: TRANSMISSION FLUID APPLICATION GUIDE - This bulletin provides information relating to the correct transmission fluid type and fill quantity requirement for each Kia model. A flush is required ONLY when a transmission is replaced, refer to applicable vehicles in the chart starting on page 2.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
What owners are reporting 2 most recent
The issue I’m having was confirmed by the dealership so when I drive on the highway, there’s a specific patch of highway that zigzags the car will follow that zigzag after getting off of the highway onto regular road. The car computer system will start a down shift erratically and feel like the car is pulling backwards. Also there is a lack of acceleration and it feels like the transmission is…
It seems the car may have a defect in the transmission(Dual Clutch). The car makes at times an abrupt stop, for like a second or two, after I press on the gas. When I'm driving, especially at low speeds I can hear the transmission's parts make a grinding sounds, loud clicks. When I'm breaking, it's not smooth at all; I feel the car pulling a bit when switching to lower gears during the breaking…
Had powertrain trouble with your 2021 Kia Forte?
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 2021 Kia Forte?
It's a documented issue but not catastrophic. 7 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?
Based on the 7 complaints filed, powertrain issues most often appear around 35,642 miles. Some report problems earlier; some make it well past 150,000 with no symptoms. Maintenance habits matter — vehicles that received timely fluid services and were not regularly overworked tend to last longer.
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/2021/Kia/Forte.
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.