Honda bulletin A21080A
What it says"ServiceNews Article - When returning the vehicle to the client, inform them that if the message Adaptive Cruise Control System Problem comes back on when the vehicle is driven in freezing conditions, it is likely… NHTSA’s full summary ↓
Honda filed this with NHTSA as a service bulletin dated Oct 17, 2023, received Sep 2, 2021, about the forward collision avoidance — 2 documents under this number. It names 14 model years (2017–2021). A service bulletin is not a safety recall: it is the manufacturer telling its dealers how to diagnose or repair a condition, and whether the work is paid for depends on the warranty in force. Quoting the number at a service desk can save a diagnosis.
Get the next Honda bulletin for your model by email Weekly, only when something new is filed. Nothing else; one-click unsubscribe.
What the bulletin says
Source: NHTSA's summary of the manufacturer's communication"ServiceNews Article - When returning the vehicle to the client, inform them that if the message Adaptive Cruise Control System Problem comes back on when the vehicle is driven in freezing conditions, it is likely because of snow or ice buildup on the radar. Advise the client of the following procedure to clean the front grille where the radar is located."
Documents filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| A21080A | Service bulletin | Oct 17, 2023 | 10244299 | PDF, 277 KB |
| A21080A | Service bulletin | Aug 31, 2021 | 10200835 | PDF, 1,745 KB |
The summary is NHTSA’s abstract of the document, as filed under 49 CFR 579.5. One communication is usually filed as several documents — the bulletin, a dealer notice, an owner letter — and the number on any of them finds this page. A PDF link is shown only once NHTSA’s own server has been seen to serve that document; the rest are checked over the following nights. Quote the number at a service desk; it is what the dealer’s system is keyed on.
Doing the repair yourself, or pricing it before the shop does? Search the part by fitment on eBay Motors — the listing and the price are the seller’s.
Find the adaptive cruise control for the 2020 Accord →Affiliate disclosure: some links on this page are affiliate links. If you request a quote or buy through them we may earn a commission at no extra cost to you. Nothing on this page changes because of it.
Model years it names
Source: as the manufacturer filed themA vehicle page’s bulletin list shows the newest few communications filed against that model year; the count there is every one.
Email me new Honda bulletins for one of these models
A weekly email, sent only in a week when Honda files something new with NHTSA for the model you pick — service bulletins, campaigns, warranty extensions, over-the-air notices, every model year. Nothing else is sent; one-click unsubscribe in every message. Separate from recall alerts.
What owners reported
Source: NHTSA complaint databaseOwners of the 14 model years this bulletin names have filed 10,656 complaints with NHTSA since 2015. 2,168 of them name Forward Collision Avoidance — the same broad component group this bulletin is filed under. NHTSA groups complaints coarsely, so that means the same area of the vehicle, not necessarily the same fault.
On the 2018 Honda Accord, the 72 owners who gave an odometer reading for Vehicle Speed Control reported it at a median of 10,000 miles. That figure is one model year’s, not the whole range this bulletin covers — medians from different model years are not averaged.
On several occasions and almost never under similar circumstances, my entire Brake System suddenly shows there is a problem and flashes warnings on my dashboard - parking brake, power steering, vehicle stability assist, hill start assist, adaptive cruise control, collision mitigation, road departure systems - each systems shows there is…
2020 Honda Accord · Forward Collision Avoidance · filed with NHTSA May 10, 2024 · ODI 11588179
I was driving on a two lane road driving over a small paved bridge going about 40mph with a car next to me and a car behind me nothing in front of me when my car did a hard phantom brake. No pre warning, the display did show BRAKE and it did beep. But everything was sudden. Luckily the car behind was able to slam on brakes.
2020 Honda Insight · Forward Collision Avoidance · filed with NHTSA Aug 25, 2024 · ODI 11610677
On two (2) occasions, the "collision mitigation braking system" braked with no reason. It has happened on a quiet and straight line residential street with no other moving vehicle, pedestrian, animal, or any other obstruction in view. After one second or so of braking, it returned to normal. It is available for inspection.
2021 Honda Insight · Forward Collision Avoidance · filed with NHTSA Jul 23, 2025 · ODI 11675632
In depth: 2020 Honda Accord automatic emergency braking problems → · 2019 Honda Accord automatic emergency braking problems → · 2018 Honda Accord automatic emergency braking problems → · 2019 Honda CR-V automatic emergency braking problems →
A complaint is one owner’s account, not a defect finding, and a bulletin is not a recall. Nothing here says this bulletin was issued because of these complaints, or that the repair it describes fixed them. Complaint files on this site begin in 2015.
More bulletins about the forward collision avoidance
Source: same model, same component group6 other manufacturer communications filed against these Honda models under the same component group (forward collision avoidance), newest first.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| ONL6UV09092026 | Other | Sep 10, 2026 | Owner Notification Letter - Honda has developed software updates to the Honda Sensing system to enhance driver experience by modifying the c… |
| A26-091 | Service bulletin | Jul 31, 2026 | Service Bulletin - Honda has developed software updates to the Honda Sensing system to enhance driver experience by modifying the circumstan… |
| AEBM07242026901 | Other | Jul 24, 2026 | Dealer Message - Due to software programming issues of the Advanced Driver Assistance System (ADAS), unexpected vehicle deceleration may occ… |
| A26-091 v1 | Service bulletin | Jul 24, 2026 | Service Bulletin - American Honda has identified a condition that may affect Collision Mitigation Braking System (CMBS) operation. Due to so… |
| ATI&04082026901 | Other | Apr 8, 2026 | Dealer Message - American Honda Motor Co., Inc. (AHM) is searching for certain 2022-2023 Civic LXs, Sports, EXs, EX-Ls or Tourings equipped… |
| A26-036 | Service bulletin | Apr 8, 2026 | "Service Bulletin - When the Adaptive Cruise Control (ACC) system is activated while driving, customers may experience unexpected cancellati… |
Quote the number at the service desk. It is what the dealer’s system is keyed on.
Every manufacturer communication NHTSA holds for Honda, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is Honda A21080A a recall?
No. A service bulletin is a manufacturer communication filed with NHTSA under 49 CFR 579.5; a safety recall carries an NHTSA campaign number (two digits, a letter, six digits) and a federal duty to repair for free. Check the vehicle’s recalls by VIN at nhtsa.gov/recalls, or on its page here.
Is the A21080A repair free?
Not automatically. A service bulletin describes how to diagnose or repair a condition; who pays depends on the warranty in force, any extension, and the dealer. Quoting the number can save a diagnosis either way. Every Honda warranty extension on file lists the ones Honda has filed.
Which vehicles does A21080A cover?
The manufacturer filed it against 14 model years: 2020 Honda Accord, 2019 Honda Accord, 2018 Honda Accord, 2019 Honda CR-V, 2018 Honda CR-V, 2017 Honda CR-V and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.