Honda bulletin A21-008
What it saysThe Hybrid System Failure message comes on the MID, and DTC P1D8D (Generator Motor Inverter Short) is stored. NHTSA’s full summary ↓
Honda filed this with NHTSA as a service bulletin dated Feb 11, 2021, received Feb 18, 2021, about the power train. It names 3 model years (2018–2020). 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.
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What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationService Bulletin - The Hybrid System Failure message comes on the MID, and DTC P1D8D (Generator Motor Inverter Short) is stored.
Trouble codes it names: P1D8D
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| A21-008 | Service bulletin | Feb 11, 2021 | 10187007 | PDF, 2,621 KB |
What the document itself lists
Parts the bulletin names
| Part number | Description | Qty | Find it |
|---|---|---|---|
| 90130-5WM-A01 | Cable Connector Bolt | 1 | eBay Motors → |
| 19012-671-300 | DT Drain Plug O-Ring | 1 | eBay Motors → |
Labour operation and the time the manufacturer allows
| Operation | Description | Time |
|---|---|---|
| 1181P3 | Replace the PCU (Includes DTC check and clear) | 2.5 hrs |
Read by machine from the document NHTSA serves (15 pages), read Oct 4, 2026. A part number is shown only where it matches Honda’s own catalogue shape, an operation only with its code and time, and a description only where the reader got it whole; anything it could not settle is left out, and the PDF is the record. Times are the manufacturer’s warranty allowances, not a quote. Listings and prices on eBay Motors are the seller’s.
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.
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 control module (tcm/pcm/tecm) for the 2020 Clarity →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.
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What owners reported
Source: NHTSA complaint databaseOwners of the 3 model years this bulletin names have filed 219 complaints with NHTSA since 2015. 103 of them name Engine, Electrical System, Power Train — 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 Clarity, the 20 owners who gave an odometer reading for Engine reported it at a median of 4,000 miles. That figure is one model year’s, not the whole range this bulletin covers — medians from different model years are not averaged.
The vehicle exhibits a dangerous electrical defect involving uncontrolled power-cycling. After shutting down the car, it automatically restarts itself in a continuous loop. During these episodes, the dashboard flickers, the drivetrain shudders, and the vehicle becomes unresponsive to manual 'Stop' button or brake inputs.
2018 Honda Clarity · Electrical System · filed with NHTSA Jan 3, 2026 · ODI 11708588
The engine revs very high and the car dramatically slows down. This has happened three times (including today) in the two years I have owned the car. Once was extremely dangerous as it happened on an Interstate highway when traffic was at highway speeds. We were able to avoid getting in an accident though.
2018 Honda Clarity · Engine · filed with NHTSA Mar 25, 2023 · ODI 11513787
The 2020 Honda Clarity's multipurpose windshield camera fails intermittently, often at startup. The vehicle displays Brake System and Honda Sensing-related warnings, disabling Collision Mitigation Braking, adaptive cruise control, lane keeping assist, and road-departure mitigation.
2020 Honda Clarity · Electrical System · filed with NHTSA Aug 22, 2026 · ODI 11758781
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.
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 A21-008 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 A21-008 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 A21-008 cover?
The manufacturer filed it against 3 model years: 2020 Honda Clarity, 2019 Honda Clarity, 2018 Honda Clarity. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.