GM bulletin PIT6127A
What it saysThis Preliminary information communicates a vehicle may come to the dealer with Super Cruise inoperative. NHTSA’s full summary ↓
GM filed this with NHTSA as a service bulletin dated Aug 13, 2024, about the electrical system. It names 7 model years across Chevrolet and Cadillac (2018–2023). 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 Super Cruise inoperative. On inspection the tech will find code B126B. Tech is given direction on how to update the Map module to restore function. Dealer is also given directions to give to customer to ensure they continue to receive updates.
Trouble codes it names: B126B
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| PIT6127A | Service bulletin | Aug 13, 2024 | 11006303 | PDF, 94 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 2 model years
Cadillac 5 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 214 complaints with NHTSA since 2015. 36 of them name Electrical System — 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.
There have been reports of Electrical Problems including the driver side mirror. The mirror housing unit seems to have an electrical issue that is causing the housing unit to overheat and deform the housing unit plastic. This has been happening to my vehicle and I'm very concern that it could develop into something more serious.
2022 Chevrolet Bolt EUV · Electrical System · filed with NHTSA Aug 5, 2026 · ODI 11755041
I was driving in a highway going at highway speed and the car suddenly just shut off and all the alert lights were reflected at that time the car was not responding completely, shut off, then within seconds after the lights flashed it started on it's own. It was the first time this happened.
2022 Cadillac XT6 · Electrical System · filed with NHTSA Sep 7, 2026 · ODI 11762586
Frightening SAFETY Problem: Sudden Power loss on Los Angeles freeway. About 6/21/2023 began repeated episodes where my Chevy 2023 Bolt EUV hesitated for a few seconds before responding when I pushed on the accelerator pedal.
2023 Chevrolet Bolt EUV · Electrical System · filed with NHTSA Sep 12, 2023 · ODI 11544123
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 electrical system
Source: same model, same component group94 other manufacturer communications filed against these GM models under the same component group (electrical system), newest first. The eight newest are listed; the rest are on the Chevrolet list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| 18-NA-180 | Service bulletin | Sep 4, 2025 | This Warranty Administration service bulletin provides Lithium-Ion battery Exchange Process and Transaction Submission information. |
| 22-NA-083 | Service bulletin | May 17, 2025 | This service bulletin provides Requirements for Replacement of the Dual Mode Cord Set Under Warranty. |
| PIE0753I | Service bulletin | May 15, 2025 | This engineering information (EI) will assist GM to recover a small number of electric vehicle battery packs from customer-owned vehicles in… |
| 24-NA-202 | Service bulletin | May 14, 2025 | This service bulletin provides dealers with Warranty Administration information on North American Charging Standard (NACS) DC Adapter Warran… |
| 22-NA-242 | Service bulletin | Apr 24, 2025 | This warranty administration bulletin provides information for dealers/technicians on System Reset and Connector Reconnect Labor Code Number… |
| 24-NA-229 | Service bulletin | Apr 10, 2025 | This bulletin provides a procedure on how to check for a battery drain utilizing the Picoscope and how to measure the load on the system tha… |
| 23-NA-036 | Service bulletin | Apr 4, 2025 | This service bulletin provides diagnostic information for dealers/technicians on an Amber Light on Dual Level Portable Charge Cord Set. |
| 25-NA-087 | Service bulletin | Apr 3, 2025 | This service bulletin provides information on the proper Reflective High Temperature Heat and/or Insulating Tape to use for certain repairs… |
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 PIT6127A 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 PIT6127A 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 PIT6127A cover?
The manufacturer filed it against 7 model years across 2 brands (Chevrolet and Cadillac): 2020 Cadillac CT6, 2019 Cadillac CT6, 2018 Cadillac CT6, 2023 Cadillac XT6, 2022 Cadillac XT6, 2023 Chevrolet Bolt EUV and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.