GM bulletin PIT6424B
What it saysA vehicle may come in with B3A6B set in history. NHTSA’s full summary ↓
GM filed this with NHTSA as a service bulletin dated Sep 10, 2025, received Sep 17, 2025. It names 25 model years across Chevrolet, GMC and Cadillac (2023–2026). 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.
One page for every brand it was filed under. Each brand’s bulletins: Chevrolet · GMC · Cadillac.
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What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationA vehicle may come in with B3A6B set in history. Tech is directed to clear code and advise the customer an OTA will be released for the code.
Trouble codes it names: B3A6B
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| PIT6424B | Service bulletin | Sep 10, 2025 | 11023158 | PDF, 110 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 9 model years
Also filed against model years this site has no page for: 2025 Chevrolet Brightdrop 400; 2025 Chevrolet Brightdrop 600.
GMC 7 model years
Also filed against model years this site has no page for: 2026 GMC Hummer EV Pickup; 2026 GMC Hummer EV SUV.
Cadillac 9 model years
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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What owners reported
Source: NHTSA complaint databaseOwners of the 21 model years this bulletin names have filed 2,362 complaints with NHTSA since 2015.
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 Chevrolet, GMC and Cadillac, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is GM PIT6424B 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 PIT6424B 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 PIT6424B cover?
The manufacturer filed it against 25 model years across 3 brands (Chevrolet, GMC and Cadillac): 2025 Cadillac Celestiq, 2026 Cadillac Escalade, 2025 Cadillac Escalade, 2026 Cadillac Lyriq, 2025 Cadillac Lyriq, 2024 Cadillac Lyriq and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.