NHTSA Complaints · Active Recalls · California Lemon Law Data
The NHTSA tracks consumer complaints, manufacturer recalls, and safety investigations for every vehicle sold in the United States. These publicly available records are a critical resource for California lemon law cases because they establish patterns of recurring defects.
As of June 2026, the NHTSA has logged 11 complaints against the 2021 Audi A4. Each complaint is filed by a vehicle owner or lessee through the NHTSA’s Vehicle Safety Hotline or online portal at SaferCar.gov. You can review all 2021 Audi A4 complaints directly on the NHTSA complaint database.
The 2021 Audi A4 has generated 12 NHTSA complaints and has 4 active recalls. If your 2021 Audi A4 has experienced a defect that the dealer has been unable to repair after multiple visits, you may qualify for a full repurchase or replacement under California lemon law. Audi pays all attorney fees when we prevail. You pay nothing.
Electrical system failures are notoriously difficult to diagnose and repair, which often results in multiple unsuccessful repair attempts — a key element of a lemon law claim. Reported issues for the 2021 Audi A4 include infotainment malfunctions, battery drain, warning lights, power window failures, and intermittent starting problems. 2 NHTSA complaints have been filed for this category. Owner reports include: “The instrument cluster has stop working. Have to monitore vehicle information, Mileage, service, Safty notifications and general vehicle information from the Audi app.” (NHTSA Complaint #11692106)
The 2021 Audi A4 has generated 1 NHTSA complaint for this defect category. If your vehicle has experienced recurring issues in this area that the dealer has been unable to repair after multiple attempts, you may have a qualifying lemon law claim under California’s Song-Beverly Consumer Warranty Act. Owner reports include: “Tires are original equipment. Only 19,000 miles on them. Was told all 4 tires have belt shifts and hop some. Suggested they should be replaced. These tires were great when new but you could tell from driving they were degrading. I’m [XXX] and never had an issue with tires this new. The belt shifting could be a manufacturing issue or hitting to many potholes. I suspect it is a combination of the two. Tire size is 245/40R18. Looking at internet reviews, these tires are great but wear out very prematurely. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)” (NHTSA Complaint #11684155)
Powertrain and transmission defects directly impair the vehicle’s core function and are generally considered substantial defects under California lemon law. Owners of the 2021 Audi A4 have reported harsh shifting, shuddering, slipping, and transmission warning lights. 1 NHTSA complaint have been submitted for this defect category. Owner reports include: “I am writing to report a persistent issue with my 2021 Audi A4, VIN [XXX] . I have been experiencing a noticeable vibration, humming, and shuddering sensation that occurs specifically when turning at slow speeds (e.g., in a parking lot or when making a tight turn at an intersection). This issue has been diagnosed at a dealership, and the diagnostic report from the service invoice dated 07/12/2025 noted “VIBRATION HUMMING SHUDDER WHILE TURNING.” The vehicle’s mileage at the time was 38,888 miles. Dealership diagnosed this issue as a failing AWD clutch system. I took the car to a different repair shop, and they redirected me to the Audi Technical Service Bulletin (TSB). The symptoms described in the TSB—”vibrations, humming, droning, or rubbing can be heard and/or felt in the vehicle interior… when the steering wheel is turned to full lock”—perfectly matches my experience. TSB Link – [XXX] The vehicle details are: Model: Audi A4 Year: 2021 VIN: [XXX] Current Mileage: 39490 Since this is an issue due to a sub-optimal part shipped by Audi, many other Audi owners are also facing similar issues. Therefore, I want to report this issue to the NHTSA and take action on cars sold by Audi. This issue divert driver attention and is a potential cause of accident while taking the turn as driver may get distracted. I already got my car serviced at Audi dealership but they didn’t inform me about this issue while the car was under warranty. Now the car is out of warranty after Apr-2025, I’m facing this issue significantly and dealership is charging close to $5000 to fix the issue. Please let me know what information you require from me to proceed. I would like Audi to place a recall on the car models facing this issue and implement the fix for all owners facing the issue because of faulty part shipped by Audi of America. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)” (NHTSA Complaint #11681029)
Advanced driver assistance system (ADAS) defects — including malfunctioning forward collision warnings, lane keep assist failures, and erratic automatic emergency braking — can create dangerous driving conditions. The 2021 Audi A4 has 1 NHTSA complaint for this defect type. Owner reports include: “The instrument cluster has failed per the recall 90VC. Audi issued the recall for every model made in 2021 with the exception of the A3 and A4 and I believe this was a mistake as my instrument cluster has the same failure.” (NHTSA Complaint #11680440)
Electrical system failures are notoriously difficult to diagnose and repair, which often results in multiple unsuccessful repair attempts — a key element of a lemon law claim. Reported issues for the 2021 Audi A4 include infotainment malfunctions, battery drain, warning lights, power window failures, and intermittent starting problems. 1 NHTSA complaint have been filed for this category. Owner reports include: “I have a 2021 audi a4 that is also being affected by the instrument cluster failure/recall. My model , a4 was not included but I am experiencing the same failure and this was reported to the dealership. An online search will show just how many people have issues with the instrument cluster. The instrument cluster screen just went out while driving. I have to monitor my functions via the app on my phone. The dealer wants to charge me full price when every other model in 2021 has been recalled for the same issue. The A4 should be added to the instrument cluster recall for 2021 audi.” (NHTSA Complaint #11677729)
The following 4 recalls have been issued for the 2021 Audi A4 by the NHTSA or Audi. If your vehicle is affected, the manufacturer is required to provide a free remedy. Check your VIN at NHTSA.gov/recalls.
Component: SEAT BELTS:REAR/OTHER:RETRACTOR
Defect: See NHTSA database for details.
Risk: An unsecured child restraint system can increase the risk of injury during a crash.
Remedy: Dealers will inspect, and replace as necessary, the middle-rear seat belt assemblies, free of charge. Owner notification letters were mailed August 27, 2021. Owners may contact Volkswagen customer service at 1-800-893-5298 and Audi customer service at 1-800-253-2834. Volkswagen’s numbers for this
Component: TIRES
Defect: See NHTSA database for details.
Risk: Rear axle misalignment may cause premature or uneven tire wear, increasing the risk of a crash.
Remedy: Dealers will inspect the rear axle, adjust the alignment as necessary, and replace any prematurely or unevenly worn tires, free of charge. Owner notification letters were mailed March 3, 2022. Owners may contact Audi customer service at 1-800-253-2834. Audi’s number for this recall is 42L5.
Component: SUSPENSION:REAR:AXLE:NON-POWERED AXLE ASSEMBLY
Defect: See NHTSA database for details.
Risk: A broken lock nut may misalign the rear axle, causing a loss of control and increasing the risk of a crash.
Remedy: Dealers will replace the lock nuts and, if necessary, the associated bolts, free of charge. Owner notification letters were mailed June 4, 2021. Owners may contact Audi customer service at 1-800-253-2834. Audi’s number for this recall is 42L1.
Component: BACK OVER PREVENTION:DISPLAY FUNCTION
Defect: See NHTSA database for details.
Risk: A blank rearview camera display can reduce the driver’s rear visibility, increasing the risk of a crash.
Remedy: Dealers will update the infotainment unit software, free of charge. Owner notification letters were mailed October 25, 2022. Owners may contact Audi’s customer service at 1-800-253-2834. Volkswagen’s number for this recall is 91DZ.
California’s Song-Beverly Consumer Warranty Act (Cal. Civ. Code §§ 1790–1795.8) is one of the strongest lemon laws in the United States. It protects buyers and lessees of new and certified pre-owned vehicles that develop substantial defects the manufacturer cannot repair after a reasonable number of attempts.
Under Cal. Civ. Code § 1793.22, a lemon law presumption is triggered when any of the following apply to your 2021 Audi A4:
Once the presumption is triggered, the burden shifts to Audi to prove the vehicle is not a lemon. Under Cal. Civ. Code § 1794(d), Audi must pay your attorney’s fees if you prevail — meaning qualified representation costs you nothing out of pocket.
If your 2021 Audi A4 qualifies as a lemon under California law, Audi may be legally required to:
Step 1: Document every repair visit. Keep all repair orders, work orders, and dealer invoices. Each visit counts as a repair attempt, even if the dealer says nothing is wrong.
Step 2: Keep returning for repairs. You must give Audi a reasonable opportunity to fix the defect. Visit different authorized Audi dealers if needed and ask for written documentation of each visit.
Step 3: Contact a California lemon law attorney. Once you believe the threshold has been met — 4 attempts for non-safety defects, 2 for safety defects, or 30 days out of service — contact an attorney for a free case evaluation. Under § 1794(d), Audi pays your fees if you win.
Step 4: Send a demand letter. Your attorney will send Audi a formal demand letter. Most California lemon law cases resolve through negotiation without going to trial.
Under Cal. Civ. Code § 1793.22, four or more repair attempts for the same non-safety defect, or two attempts for a safety-related defect, triggers the lemon law presumption. Additionally, 30 or more cumulative days out of service qualifies regardless of the number of repair attempts.
Yes. Under Cal. Civ. Code § 1794(d), Audi is required to pay your reasonable attorney’s fees and court costs if you prevail in a lemon law claim. This means qualified lemon law representation is free to you if your case succeeds.
Yes. A recall is not required to file a lemon law claim. The Song-Beverly Act covers any substantial defect that impairs the use, value, or safety of the vehicle that the manufacturer cannot repair after a reasonable number of attempts. NHTSA complaints support the claim by establishing a pattern, but are not a prerequisite.
California lemon law claims are generally subject to a four-year statute of limitations from the date you discovered or should have discovered the defect. However, you must still be within the manufacturer’s original warranty period when the defect first appears. Contact an attorney promptly to preserve your rights.
If your 2021 Audi A4 has a recurring defect, California’s Lemon Law may entitle you to a full refund, replacement vehicle, or cash settlement — at no cost to you.
Our attorneys answer the questions we hear most from California vehicle owners — fully updated for 2026.
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