GM bulletin PIT6521
What it saysThis PI advises dealers that if DTC P0606 and/or P0607 are set in the K160 EBCM, additional diagnostic aids should be followed to ensure the module requires replacement NHTSA’s full summary ↓
GM filed this with NHTSA as a service bulletin dated Jun 9, 2026, received Jun 18, 2026. It names 11 model years across Chevrolet, GMC and Buick (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 · Buick.
Get the next GM bulletin for your model by email Weekly, only when something new is filed. Nothing else; one-click unsubscribe.
What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationThis PI advises dealers that if DTC P0606 and/or P0607 are set in the K160 EBCM, additional diagnostic aids should be followed to ensure the module requires replacement
Trouble codes it names: P0606 P0607
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| PIT6521 | Service bulletin | Jun 9, 2026 | 11033988 | 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 6 model years
GMC 4 model years
Buick 1 model year
A vehicle page’s bulletin list shows the newest few communications filed against that model year; the count there is every one.
Email me new GM bulletins for one of these models
A weekly email, sent only in a week when GM 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.
What owners reported
Source: NHTSA complaint databaseOwners of the 11 model years this bulletin names have filed 936 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 Buick, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is GM PIT6521 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 PIT6521 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 PIT6521 cover?
The manufacturer filed it against 11 model years across 3 brands (Chevrolet, GMC and Buick): 2025 Buick Enclave, 2026 Chevrolet Colorado, 2025 Chevrolet Colorado, 2024 Chevrolet Colorado, 2023 Chevrolet Colorado, 2025 Chevrolet Traverse and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.