GM bulletin PIT6352A
What it saysThis Preliminary information communicates A vehicle may come to the dealer with a service high voltage message and P29BB. NHTSA’s full summary ↓
GM filed this with NHTSA as a service bulletin dated Mar 27, 2025, received Apr 1, 2025. It names 7 model years across Chevrolet and Cadillac (2024–2026). 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 · Cadillac.
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What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationThis Preliminary information communicates A vehicle may come to the dealer with a service high voltage message and P29BB. The dealer is advised not to replace the heater. They are to clear the code and advise the customer that engineering is working on a design improvement.
Trouble codes it names: P29BB
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| PIT6352A | Service bulletin | Mar 27, 2025 | 11016170 | PDF, 27 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 4 model years
Cadillac 3 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 7 model years this bulletin names have filed 841 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 and Cadillac, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is GM PIT6352A 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 PIT6352A 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 PIT6352A cover?
The manufacturer filed it against 7 model years across 2 brands (Chevrolet and Cadillac): 2025 Cadillac Lyriq, 2025 Cadillac Optiq, 2026 Cadillac Vistiq, 2025 Chevrolet Blazer, 2024 Chevrolet Blazer, 2025 Chevrolet Equinox and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.