Honda bulletin A24040A
What it saysService NewsDue to On-Board Diagnostic (OBD) regulation change starting with 2019 vehicles, American Honda’s Variable Valve Timing and Lift Electronic Control (VTEC) On-Board Diagnostic monitors are now included… NHTSA’s full summary ↓
Honda filed this with NHTSA as a manufacturer communication dated May 1, 2024, received May 15, 2024, about the engine. It names 29 model years (2019–2025). A manufacturer communication 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.
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What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationService NewsDue to On-Board Diagnostic (OBD) regulation change starting with 2019 vehicles, American Honda’s Variable Valve Timing and Lift Electronic Control (VTEC) On-Board Diagnostic monitors are now included in the EGR/VVT OBD Monitor Readiness status group. Due to some customer’s driving patterns, they may not drive in the fashion needed to operate the VTEC (EGR/VVT) that only operates above 5,350 rpm to run the OBD monitoring. Therefore, the EGR/VVT OBD monitor group readiness status is not set to “Complete” when the customer presents their vehicle to a Smog Check station for inspection.
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| A24040A | Other | May 1, 2024 | 11000142 | PDF, 41 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.
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.
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What owners reported
Source: NHTSA complaint databaseOwners of the 29 model years this bulletin names have filed 7,753 complaints with NHTSA since 2015. 1,589 of them name Engine — 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 2019 Honda CR-V, the 47 owners who gave an odometer reading for Engine reported it at a median of 8,100 miles. That figure is one model year’s, not the whole range this bulletin covers — medians from different model years are not averaged.
Engine fails to restart after Idle Stop engaged. Engine stops normally when brake pedal is pressed and vehicle comes to full stop. Brake pedal is then released to restart engine but the engine does not start. Dashboard says "Shift to Park". The transmission is shifted to Park and then Start button is pushed to restart engine.
2020 Honda Ridgeline · Engine · filed with NHTSA Oct 12, 2022 · ODI 11488999
Car wouldn't go more than 25-30 miles/hour and rpm was at 5-6, had to use blinkers on highway. Luckily there weren't any injuries, i was scared of the situation as I was travelling with my toddler and newborn. After reaching home, car wouldn't reverse. I had shutdown and started the car multiple times before i could reverse.
2023 Honda Pilot · Engine · filed with NHTSA Sep 27, 2023 · ODI 11546998
After approximately 2 unbroken hours of driving North on I-35 from Minneapolis on January 24th, 2022, I exited the freeway at exit 214 near Moose Lake. I came to a stop at the top of the ramp (stop sign) to allow cross traffic to clear and then proceeded to accelerate while turning left to cross the bridge over the freeway.
2021 Honda Ridgeline · Engine · filed with NHTSA Apr 4, 2022 · ODI 11459570
In depth: 2019 Honda CR-V engine problems → · 2025 Honda Odyssey engine problems → · 2024 Honda Odyssey engine problems → · 2020 Honda Odyssey engine 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 engine
Source: same model, same component group72 other manufacturer communications filed against these Honda models under the same component group (engine), newest first. The eight newest are listed; the rest are on the Honda list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| A26-098 | Service bulletin | Sep 25, 2026 | Service Bulletin - Under certain conditions, the cylinder head gasket effectiveness may be reduced which may cause vehicles to experience ov… |
| A26-019 | Service bulletin | Sep 25, 2026 | Service Bulletin - Under certain conditions, the cylinder head gasket effectiveness may be reduced which may cause vehicles to experience ov… |
| A26-018 | Service bulletin | Sep 25, 2026 | Service Bulletin - Under certain conditions, the cylinder head gasket effectiveness may be reduced which may cause vehicles to experience ov… |
| A26-017 | Service bulletin | Sep 25, 2026 | Service Bulletin - Under certain conditions, the cylinder head gasket effectiveness may be reduced which may cause vehicles to experience ov… |
| A26-016 | Service bulletin | Sep 25, 2026 | Service Bulletin - Under certain conditions, the cylinder head gasket effectiveness may be reduced which may cause vehicles to experience ov… |
| AEBM08262026901 | Other | Aug 26, 2026 | Dealer Message - Under certain conditions, the cylinder head gasket effectiveness may be reduced which may cause vehicles to experience over… |
| A25-017 | Service bulletin | Jun 23, 2026 | Service Bulletin - A slight engine vibration and the Malfunction Indicator Lamp (MIL) is ON with DTC P0700… |
| ATI&05122026902 | Other | May 13, 2026 | Dealer Message - American Honda Motor Co., Inc. (AHM) is searching for certain 2024-2026 Odysseys & Ridgelines and 2024-2025 Passports with… |
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 A24040A a recall?
No. A manufacturer communication 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 A24040A 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 A24040A cover?
The manufacturer filed it against 29 model years: 2019 Honda CR-V, 2025 Honda Odyssey, 2024 Honda Odyssey, 2023 Honda Odyssey, 2022 Honda Odyssey, 2021 Honda Odyssey and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.