What is the 2021-2024 Hyundai Elantra Phantom / False Automatic Emergency Braking and Forward Collision Activation?

The Forward Collision-Avoidance Assist (FCA) and Blind-Spot Collision-Avoidance systems can trigger hard automatic emergency braking when no real obstacle is present. Owners report sudden, unprompted braking at 40-65 mph on open road, plus false activation when a vehicle passes c… Repairs typically run $0-$350. Severity: high.

What is the 2019-2023 Hyundai Elantra IVT/CVT Transmission Failure and Power Loss?

The Smart Stream IVT (Intelligent Variable Transmission) in newer Elantras has experienced early failures, sometimes before reaching 20,000 miles. Issues include sudden power loss, check engine lights, and RPM fluctuations. Hyundai issued TSB 20-01-047H addressing transmission co… Repairs typically run $0-$5,500. Severity: medium.

What is the 2021-2022 Hyundai Elantra Rearview Camera Printed Circuit Board Damage Causing Loss of Backup Image (Recall 24V879)?

CN7-generation Elantras, Elantra Hybrids and the 2022 Elantra N were built with rearview cameras whose internal printed circuit board can be damaged, so the reversing image fails to display on the centre screen. The car then does not comply with FMVSS 111 'Rear Visibility'. Owner… Repairs typically run $0-$0. Severity: medium.

What is the 2011-2022 Hyundai Elantra P0420 — Catalyst Efficiency Below Threshold (Bank 1), Often Downstream of Nu 2.0L Oil Consumption?

P0420 on the Elantra means the downstream (post-cat) oxygen sensor sees the catalytic converter no longer scrubbing efficiently. On the 2017-2020 Nu 2.0L engine this frequently is not just an aged cat — it is a symptom of the well-documented Nu 2.0L piston-ring/oil-consumption de… Repairs typically run $300-$1,800. Severity: medium.

Hyundai · Known Issues

2021 Hyundai Elantra Problems: 8 Known Issues

2021 model year · 456+ owner reports · Updated September 2026

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According to Au7o's analysis of 456+ owner reports, the 2021 Hyundai Elantra has 8 documented known issues, with 5 rated critical. The most serious are Front Seat Belt Pretensioner May Explode and Project Metal Fragments (Recall 229), Theft Vulnerability — Missing Engine Immobilizer ('Kia Boyz' / TikTok Challenge), Non-Conforming Clear Coat Causing Inadequate Windshield Bonding and Detachment in a Crash (Recall 216 / 21V00M) ($0-$0 repair), Hybrid Motor Control Unit Software Error Causing Unintended Acceleration After Brake Release (Recall 23V589) ($0-$0 repair) and Phantom / False Automatic Emergency Braking and Forward Collision Activation ($0-$350 repair). The most commonly reported issue is IVT/CVT Transmission Failure and Power Loss with 456 owner reports. Across all issues with published estimates, repair costs range from $300 to $5,500. DIY maintenance guides at au7o.io.

Frequently Asked Questions

What are the most common Hyundai Elantra problems?

According to Au7o's analysis of 456+ owner reports, the 2021 Hyundai Elantra has 8 documented issues. The most frequently reported are: Front Seat Belt Pretensioner May Explode and Project Metal Fragments (Recall 229), Theft Vulnerability — Missing Engine Immobilizer ('Kia Boyz' / TikTok Challenge), Non-Conforming Clear Coat Causing Inadequate Windshield Bonding and Detachment in a Crash (Recall 216 / 21V00M). Of these, 5 are rated critical and should be addressed promptly.

Is the Hyundai Elantra reliable?

The 2021 Hyundai Elantra has 8 known issues documented across 456+ owner reports. 5 issues are rated critical: Front Seat Belt Pretensioner May Explode and Project Metal Fragments (Recall 229) and Theft Vulnerability — Missing Engine Immobilizer ('Kia Boyz' / TikTok Challenge) and Non-Conforming Clear Coat Causing Inadequate Windshield Bonding and Detachment in a Crash (Recall 216 / 21V00M) and Hybrid Motor Control Unit Software Error Causing Unintended Acceleration After Brake Release (Recall 23V589) and Phantom / False Automatic Emergency Braking and Forward Collision Activation. 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 Hyundai Elantra problems?

Repair costs for known Hyundai Elantra issues range from $0 to $5,500, depending on the specific problem and whether you choose DIY or professional repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.

What is the 2021-2022 Hyundai Elantra Front Seat Belt Pretensioner May Explode and Project Metal Fragments (Recall 229)?

NHTSA recall 22V354 includes certain 2021-2022 Hyundai Elantra and Elantra HEV vehicles. A driver- or passenger-side pyrotechnic pretensioner may deploy abnormally in a crash because its pipe can over-pressurize, allowing metal fragments to enter the occupant compartment and inju… Severity: high.

All 8 Known Issues

Other Hyundai Models

Frequently Asked Questions

What are the most common Hyundai Elantra problems?

Is the Hyundai Elantra reliable?

How much does it cost to fix common Hyundai Elantra problems?

What is the 2021-2022 Hyundai Elantra Front Seat Belt Pretensioner May Explode and Project Metal Fragments (Recall 229)?

What is the 2011-2022 Hyundai Elantra Theft Vulnerability — Missing Engine Immobilizer ('Kia Boyz' / TikTok Challenge)?

2011-2022 Hyundai Elantra: Theft Vulnerability — Missing Engine Immobilizer ('Kia Boyz' / TikTok Challenge)#

2021-2023 Hyundai Elantra: Hybrid Motor Control Unit Software Error Causing Unintended Acceleration After Brake Release (Recall 23V589)#

2021-2022 Hyundai Elantra: Rearview Camera Printed Circuit Board Damage Causing Loss of Backup Image (Recall 24V879)#

2021-2022 Hyundai Elantra: Front Seat Belt Pretensioner May Explode and Project Metal Fragments (Recall 229)#

2021-2024 Hyundai Elantra: Phantom / False Automatic Emergency Braking and Forward Collision Activation#

2021 Hyundai Elantra: Non-Conforming Clear Coat Causing Inadequate Windshield Bonding and Detachment in a Crash (Recall 216 / 21V00M)#

2019-2023 Hyundai Elantra: IVT/CVT Transmission Failure and Power Loss#

2011-2022 Hyundai Elantra: P0420 — Catalyst Efficiency Below Threshold (Bank 1), Often Downstream of Nu 2.0L Oil Consumption#

What is the 2021 Hyundai Elantra Non-Conforming Clear Coat Causing Inadequate Windshield Bonding and Detachment in a Crash (Recall 216 / 21V00M)?

What is the 2021-2023 Hyundai Elantra Hybrid Motor Control Unit Software Error Causing Unintended Acceleration After Brake Release (Recall 23V589)?

What is the 2021-2024 Hyundai Elantra Phantom / False Automatic Emergency Braking and Forward Collision Activation?

What is the 2019-2023 Hyundai Elantra IVT/CVT Transmission Failure and Power Loss?

What is the 2021-2022 Hyundai Elantra Rearview Camera Printed Circuit Board Damage Causing Loss of Backup Image (Recall 24V879)?

What is the 2011-2022 Hyundai Elantra P0420 — Catalyst Efficiency Below Threshold (Bank 1), Often Downstream of Nu 2.0L Oil Consumption?