GM bulletin PIT6559
What it saysThis Preliminary Information communicates the fact that multiple parts for this vehicle are on a part restriction. NHTSA’s full summary ↓
GM filed this with NHTSA as a service bulletin dated Oct 16, 2026, received Oct 20, 2026. It names 2 model years across Chevrolet and GMC (2027). 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.
One page for every brand it was filed under. Each brand’s bulletins: Chevrolet · GMC.
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What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationThis Preliminary Information communicates the fact that multiple parts for this vehicle are on a part restriction. Dealers are directed to check EPC for restriction notes and that it will require additional processes to obtain a restricted part.
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| PIT6559 | Service bulletin | Oct 16, 2026 | 11038594 | PDF, 108 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 themChevrolet 1 model year
GMC 1 model year
Also filed against: 2027 GMC Sierra 1500.
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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Quote the number at the service desk. It is what the dealer’s system is keyed on.
Every manufacturer communication NHTSA holds for Chevrolet and GMC, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is GM PIT6559 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 PIT6559 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 GM warranty extension on file lists the ones GM has filed.
Which vehicles does PIT6559 cover?
The manufacturer filed it against 2 model years across 2 brands (Chevrolet and GMC): 2027 Chevrolet Silverado, 2027 GMC Sierra 1500. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.