What is the 2021-2024 Kia K5 Forward Collision Avoidance Assist (FCA) Phantom Braking Events?

Multiple K5 owners and NHTSA complaints document unexpected, uninitiated hard braking events triggered by the Forward Collision Avoidance Assist system in the absence of any actual obstacle. These phantom braking events occur most commonly on highways, elevated roads, or in areas… Severity: high.

What is the 2021-2024 Kia K5 SmartStream G2.5 GDI Engine Piston Ring/Oil Consumption Issue?

Owners of K5 models equipped with the 2.5L naturally aspirated GDI engine (SmartStream G2.5) have reported excessive oil consumption between change intervals, sometimes consuming over a quart per 1,000 miles. The root cause is linked to piston ring sealing tolerances that allow o… Severity: high.

What is the 2021-2024 Kia K5 Electronic Parking Brake (EPB) Warning / Auto-Hold Malfunction?

NHTSA complaints and owner reports note intermittent EPB warnings and Auto-Hold faults on Kia K5, sometimes accompanied by the parking brake not applying/releasing as expected. The issue is commonly linked to EPB actuator/motor faults, wiring/connector issues at the rear calipers… Repairs typically run $180-$900. Severity: high.

What is the 2021-2024 Kia K5 Rear Wheel Bearing Premature Failure and Humming Noise?

A number of K5 owners have reported premature rear wheel bearing failure, typically presenting as a low-pitched humming or growling noise that changes with vehicle speed and varies when turning left or right. The issue has been observed on both FWD and AWD variants and appears li… Repairs typically run $250-$650. Severity: high.

What is the 2021-2024 Kia K5 Brake Booster / Vacuum Pump Noise and Reduced Brake Assist (1.6T)?

On 1.6T turbocharged K5 variants, some owners and NHTSA complainants have reported a hissing sound from the brake booster area upon brake pedal application, accompanied by a noticeably harder brake pedal and reduced power assistance. The GDi turbocharged engine uses an electric v… Repairs typically run $50-$900. Severity: high.

What is the 2021-2023 Kia K5 Fuel Tank Expansion and Fire Risk?

NHTSA recall 25V794000 (Kia SC356) covers 2021-2024 K5 vehicles equipped with the 1.6L T-GDI engine. A deteriorated purge-control-system check valve can allow pressurized intake air into the fuel tank. The tank can expand, contact hot exhaust components and locally melt, which ca… Severity: high.

What is the 2021-2023 Kia K5 8-Speed DCT Electric Oil Pump Failure?

NHTSA recall 22V760000 (Kia SC250) covers certain 2021-2023 K5 vehicles equipped with the 2.5L T-GDI engine and 8-speed dual-clutch transmission. A supplier soldering defect can cause an internal electric oil-pump circuit-board fault. The vehicle may chime, display “stop safely i… Severity: high.

What is the 2021-2024 Kia K5 Front Suspension Strut Mount/Bearing Noise (Creak/Pop While Turning)?

Kia K5 owners report creaking, popping, or groaning noises from the front suspension during steering input, especially at low speeds or when parking. The issue is often tied to strut mount bearings binding or premature wear, sometimes exacerbated by moisture intrusion. The noise… Repairs typically run $250-$900. Severity: medium.

What is the 2021-2024 Kia K5 Door Handle/Lock Actuator Failure (Door Won’t Open or Won’t Lock/Unlock)?

Owner reports and NHTSA complaints note exterior door handles and/or door lock actuators failing, leading to doors that won’t open from outside (and sometimes inside) or won’t lock/unlock reliably. Failures are commonly tied to actuator motor wear, latch mechanism binding, or lin… Repairs typically run $180-$650. Severity: medium.

What is the 2021-2023 Kia K5 Steering Column/Intermediate Shaft Clunk or Knock (Low-Speed Turns)?

Owner reports and NHTSA complaints describe a clunk/knock felt through the steering wheel during low-speed turning or over small bumps. The condition is commonly associated with play in the intermediate steering shaft, column coupling, or related fasteners/bushings. Drivers repor… Repairs typically run $120-$650. Severity: medium.

What is the 2021-2023 Kia K5 Wireless Phone Charging Pad Overheating and Device Damage?

K5 models equipped with the optional wireless charging pad have generated NHTSA complaints and owner forum reports describing the pad running excessively hot during charging cycles, causing smartphones to display thermal warnings and in some cases warping or discoloring the charg… Severity: medium.

What is the 2021-2024 Kia K5 Turbocharger Oil Feed/Return Leak (1.6T) Causing Burning Oil Smell/Smoke?

Owner reports and NHTSA complaints on 1.6L turbo K5 models describe oil seepage/leaks around the turbocharger oil feed/return lines or related seals, sometimes producing a burning oil smell and light smoke after driving. Heat cycling can harden seals or loosen fittings, allowing… Repairs typically run $220-$1,200. Severity: medium.

What is the 2021-2024 Kia K5 8-Speed DCT Low-Speed Hesitation and Shudder?

Kia bulletin TRA100 documents clutch judder on some 2021 model year and later K5 GT vehicles equipped with the 2.5L T-GDI engine and 8-speed wet dual-clutch transmission. Kia defines the condition as body vibration, without steering-wheel shudder, during a controlled creep-drivin… Severity: medium.

What is the 2021-2025 Kia K5 Infotainment Screen Blackout and Random Reboots?

The K5 infotainment system — both the 8-inch and 10.25-inch displays — experiences random screen blackouts, freezes, and spontaneous reboots. The screen may go completely black while driving, losing access to navigation, backup camera, and climate controls. Some owners report the… Repairs typically run $0-$2,000. Severity: medium.

What is the 2021-2025 Kia K5 ADAS Sensor Calibration Faults (Lane Keep, Forward Collision)?

The Advanced Driver Assistance Systems on the K5 — including Lane Keep Assist, Forward Collision Avoidance, and Blind Spot Monitoring — intermittently throw calibration faults and disable themselves. The forward-facing camera behind the windshield and radar sensor in the front bu… Repairs typically run $0-$1,500. Severity: medium.

What is the 2021-2025 Kia K5 Theta II Engine Knock Sensor Issues and Knock-Related Concerns?

The 2.5L Theta II engine in certain K5 models has experienced knock sensor faults and engine knock concerns. The knock sensor may trigger false positives or fail to detect actual detonation, causing the ECU to either retard timing unnecessarily (reducing power) or fail to protect… Repairs typically run $0-$400. Severity: medium.

What is the 2021-2024 Kia K5 Paint Chipping and Clear Coat Peeling (Hood and Roof Panel)?

K5 owners across multiple model years have reported premature paint chipping on the hood and roof panels, with the clear coat peeling in flakes or bubbling in affected areas. This is documented in Kia owner forums and in some NHTSA complaints, particularly in darker colors such a… Repairs typically run $200-$1,800. Severity: low.

Kia · Known Issues

2021 Kia K5 Problems: 24 Known Issues

2021 model year · 1,192+ owner reports · Updated August 2026

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According to Au7o's analysis of 1,192+ owner reports, the 2021 Kia K5 has 24 documented known issues, with 10 rated critical. The most serious are Battery Drain / No-Start After Sitting (Telematics/Module Sleep Issue) ($180-$1,200 repair), Forward Collision Avoidance Assist (FCA) Phantom Braking Events, SmartStream G2.5 GDI Engine Piston Ring/Oil Consumption Issue, Electronic Parking Brake (EPB) Warning / Auto-Hold Malfunction ($180-$900 repair), Rear Wheel Bearing Premature Failure and Humming Noise ($250-$650 repair), Transmission Control Unit (TCU) Software Fault Causing Harsh Upshifts or Limp Mode (8-Speed AT), Windshield Optical/Rain Sensor Bracket Detachment (ADAS/Auto Wipers Inoperative) ($250-$1,400 repair), Brake Booster / Vacuum Pump Noise and Reduced Brake Assist (1.6T) ($50-$900 repair).

Frequently Asked Questions

What are the most common Kia K5 problems?

According to Au7o's analysis of 1,192+ owner reports, the 2021 Kia K5 has 24 documented issues. The most frequently reported are: Battery Drain / No-Start After Sitting (Telematics/Module Sleep Issue), Forward Collision Avoidance Assist (FCA) Phantom Braking Events, SmartStream G2.5 GDI Engine Piston Ring/Oil Consumption Issue. Of these, 10 are rated critical and should be addressed promptly.

Is the Kia K5 reliable?

The 2021 Kia K5 has 24 known issues documented across 1,192+ owner reports. 10 issues are rated critical: Battery Drain / No-Start After Sitting (Telematics/Module Sleep Issue) and Forward Collision Avoidance Assist (FCA) Phantom Braking Events and SmartStream G2.5 GDI Engine Piston Ring/Oil Consumption Issue and Electronic Parking Brake (EPB) Warning / Auto-Hold Malfunction and Rear Wheel Bearing Premature Failure and Humming Noise and Transmission Control Unit (TCU) Software Fault Causing Harsh Upshifts or Limp Mode (8-Speed AT) and Windshield Optical/Rain Sensor Bracket Detachment (ADAS/Auto Wipers Inoperative) and Brake Booster / Vacuum Pump Noise and Reduced Brake Assist (1.6T) and Fuel Tank Expansion and Fire Risk and 8-Speed DCT Electric Oil Pump Failure. Prospective buyers should inspect for these issues and factor potential repair costs into their purchase decision. Regular maintenance following the manufacturer's schedule helps prevent many common problems.

How much does it cost to fix common Kia K5 problems?

Repair costs for known Kia K5 issues range from $0 to $2,000, depending on the specific problem and whether you choose DIY or professional repair. The most critical issue, Battery Drain / No-Start After Sitting (Telematics/Module Sleep Issue), typically costs $180-$1,200 to repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.

What is the 2021-2023 Kia K5 Battery Drain / No-Start After Sitting (Telematics/Module Sleep Issue)?

NHTSA complaints and owner reports describe repeated dead 12V batteries and no-start conditions after the vehicle sits for 1–3 days. Reports often point to excessive parasitic draw from modules not entering sleep mode (commonly infotainment/telematics-related) or repeated wake-up… Repairs typically run $180-$1,200. Severity: high.

All 24 Known Issues

Other Kia Models

Frequently Asked Questions

What are the most common Kia K5 problems?

Is the Kia K5 reliable?

How much does it cost to fix common Kia K5 problems?

What is the 2021-2023 Kia K5 Battery Drain / No-Start After Sitting (Telematics/Module Sleep Issue)?

When Issues Typically Appear

2021-2024 Kia K5: Transmission Control Unit (TCU) Software Fault Causing Harsh Upshifts or Limp Mode (8-Speed AT)#

2021-2023 Kia K5: 8-Speed DCT Electric Oil Pump Failure#

2021-2024 Kia K5: 8-Speed DCT Low-Speed Hesitation and Shudder#

2021-2024 Kia K5: Forward Collision Avoidance Assist (FCA) Phantom Braking Events#

2021-2024 Kia K5: Windshield Optical/Rain Sensor Bracket Detachment (ADAS/Auto Wipers Inoperative)#

2021-2024 Kia K5: Electronic Parking Brake (EPB) Warning / Auto-Hold Malfunction#

2021-2024 Kia K5: Brake Booster / Vacuum Pump Noise and Reduced Brake Assist (1.6T)#

2021-2023 Kia K5: Battery Drain / No-Start After Sitting (Telematics/Module Sleep Issue)#

2021-2023 Kia K5: Wireless Phone Charging Pad Overheating and Device Damage#

2021-2025 Kia K5: Infotainment Screen Blackout and Random Reboots#

2021-2025 Kia K5: ADAS Sensor Calibration Faults (Lane Keep, Forward Collision)#

2021-2024 Kia K5: SmartStream G2.5 GDI Engine Piston Ring/Oil Consumption Issue#

2021-2024 Kia K5: Turbocharger Oil Feed/Return Leak (1.6T) Causing Burning Oil Smell/Smoke#

2021-2025 Kia K5: Theta II Engine Knock Sensor Issues and Knock-Related Concerns#

2021-2024 Kia K5: Rear Wheel Bearing Premature Failure and Humming Noise#

2021-2024 Kia K5: Front Suspension Strut Mount/Bearing Noise (Creak/Pop While Turning)#

2021-2023 Kia K5: Steering Column/Intermediate Shaft Clunk or Knock (Low-Speed Turns)#

2021-2023 Kia K5: Fuel Tank Expansion and Fire Risk#

2021-2024 Kia K5: Door Handle/Lock Actuator Failure (Door Won’t Open or Won’t Lock/Unlock)#

2021-2024 Kia K5: Paint Chipping and Clear Coat Peeling (Hood and Roof Panel)#

2021-2025 Kia K5: Panoramic Sunroof Rattle and Water Leak#

2021-2025 Kia K5: Rear Trunk Latch Sticking and Failure to Open#

2021-2024 Kia K5: HVAC Blower Motor Noise/Failure (Squeal, Rattle, Intermittent Fan)#

2021-2024 Kia K5: Heated and Ventilated Seat Malfunction (Element Failure or Fan Noise)#