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Manufacturer communication · Service bulletin

Subaru bulletin 18-230-26

What it saysThis bulletin announces the diagnostic procedures to be used when DTCs B1571(REFERENCE CODE INCOMPATIBILITY IMMOBILIZER CM TO ECM) and B1572(IMM CIRCUIT EXCEPT ANTENNA CIRCUIT) are detected by Keyless Access with Push… NHTSA’s full summary ↓

Subaru filed this with NHTSA as a service bulletin dated May 1, 2026, received Jun 1, 2026, about the engine. It names 74 model years (2016–2026). 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 communication

This bulletin announces the diagnostic procedures to be used when DTCs B1571(REFERENCE CODE INCOMPATIBILITY IMMOBILIZER CM TO ECM) and B1572(IMM CIRCUIT EXCEPT ANTENNA CIRCUIT) are detected by Keyless Access with Push Button Start(KACM).

Trouble codes it names: B1571 B1572

Kind Service bulletin Manufacturer date May 1, 2026 Received by NHTSA Jun 1, 2026 Components Engine

Document filed under this number

DocumentKindDatedNHTSA idAt NHTSA
18-230-26Service bulletinMay 1, 202611033051PDF, 2,498 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 them

and 34 more on this site: 2021 Subaru Impreza, 2020 Subaru Impreza, 2019 Subaru Impreza, 2018 Subaru Impreza, 2017 Subaru Impreza, 2016 Subaru Impreza/Outback Sport, 2025 Subaru Legacy, 2024 Subaru Legacy, 2023 Subaru Legacy, 2022 Subaru Legacy, 2021 Subaru Legacy, 2020 Subaru Legacy, 2019 Subaru Legacy, 2018 Subaru Legacy, 2017 Subaru Legacy/Outback, 2016 Subaru Legacy/Outback, 2025 Subaru Outback, 2024 Subaru Outback, 2023 Subaru Outback, 2022 Subaru Outback, 2021 Subaru Outback, 2020 Subaru Outback, 2019 Subaru Outback, 2018 Subaru Outback, 2026 Subaru WRX, 2025 Subaru WRX, 2024 Subaru WRX, 2023 Subaru WRX, 2022 Subaru WRX, 2021 Subaru WRX, 2020 Subaru WRX, 2019 Subaru WRX, 2018 Subaru WRX, 2017 Subaru WRX.

A 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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A weekly email, sent only in a week when Subaru 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.

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What owners reported

Source: NHTSA complaint database

Owners of the 74 model years this bulletin names have filed 12,597 complaints with NHTSA since 2015. 1,016 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 2016 Subaru Forester, the 33 owners who gave an odometer reading for Engine reported it at a median of 42,000 miles. That figure is one model year’s, not the whole range this bulletin covers — medians from different model years are not averaged.

Driving my car as any person would, at the 3519 mile mark on the odometer the engine low oil light came on, it took (1.5Q) of oil to top it off. This is a brand new car no one buys a new car to add oil to it, then to get told by the dealership that it’s normal for up to (2Q) of oil to be added because it’s the only AWD boxer, but yet the…

2024 Subaru WRX · Engine · filed with NHTSA Mar 24, 2025

At around the 2000 mile mark I noticed a drastic reduction in fuel econemy. I also started noticing metal particles in the engine oil. I also noticed a significant drop in engine power as well. This is a sign of debris getting in the engine and causing metal particles to become broken off. My mileage went from 460-480 mpt to 360-380 mpt.

2019 Subaru Crosstrek · Engine · filed with NHTSA Oct 27, 2019

I would just like to complain about the excess Rtv on the engine oil pan that has been demonstrated on numerous videos of people opening up the oil drain pan and finding chunks of Rtv blocking some of the engine oil pickup tube. I have not opened up my oil drain pan due to cost. This has not lead to failure as of yet but it is worrisome.

2023 Subaru WRX · Engine · filed with NHTSA Jul 18, 2024

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 group

57 other manufacturer communications filed against these Subaru models under the same component group (engine), newest first. The eight newest are listed; the rest are on the Subaru list.

NumberKindDatedNHTSA’s summary
09-98-22RService bulletinAug 31, 2026This bulletin announces the availability of new reprograming files for the Engine Control Module (ECM) developed to remedy the following DTC…
02-196-26RService bulletinAug 20, 2026This service bulletin outlines the diagnostic and repair procedure for white smoke emitted from the exhaust after startup. This is an revise…
07-231-26Service bulletinAug 5, 2026This bulletin announces the service procedure for battery replacement on 2025-2026MY Impreza and Crosstrek.
02-193-24RService bulletinJun 30, 2026This bulletin provides updated parts information and a service procedure to follow for removing accumulated carbon deposits from fuel inject…
09-74-21RService bulletinJun 26, 2026This bulletin provides updated parts information and a service procedure to follow for removing accumulated carbon deposits from fuel inject…
02-196-26Service bulletinJun 23, 2026This bulletin outlines the diagnostic and repair procedure for white smoke emitted from the exhaust after startup.
18-243-26Service bulletinJun 11, 2026This bulletin announces the elimination of oil spacers from both left- and right side camshaft carriers on FB2.5 engines.
09-130-25RService bulletinJun 3, 2026This bulletin announces the design change made to the exhaust manifold flange nut material that has been changed from stainless steel to med…

Quote the number at the service desk. It is what the dealer’s system is keyed on.

Every manufacturer communication NHTSA holds for Subaru, by the number printed on the letter.

Photo: Christian Buehner / Unsplash

Common questions

Source: NHTSA, 49 CFR 579.5

Is Subaru 18-230-26 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 18-230-26 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.

Which vehicles does 18-230-26 cover?

The manufacturer filed it against 74 model years: 2026 Subaru Ascent, 2025 Subaru Ascent, 2024 Subaru Ascent, 2023 Subaru Ascent, 2022 Subaru Ascent, 2021 Subaru Ascent and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.