GM bulletin 07-08-42-006T
What it saysThis service bulletin provides technicians with information on available BCM calibrations to restore bulb outage detection on vehicles produced by a second stage manufacturer (Upfitter), and/or turn signals flash fast… NHTSA’s full summary ↓
GM filed this with NHTSA as a service bulletin dated Mar 25, 2025, received Apr 25, 2025, about the exterior lighting. It names 48 model years across Chevrolet and GMC (2016–2025). 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 service bulletin provides technicians with information on available BCM calibrations to restore bulb outage detection on vehicles produced by a second stage manufacturer (Upfitter), and/or turn signals flash fast after factory box removed.
Trouble codes it names: B3950 B3951 all 2 read from the document itself; NHTSA’s summary names none
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| 07-08-42-006T | Service bulletin | Mar 25, 2025 | 11017243 | PDF, 120 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 24 model years
GMC 24 model years
and 8 more on this site: 2019 GMC Sierra 2500HD, 2025 GMC Sierra 3500HD, 2024 GMC Sierra 3500HD, 2023 GMC Sierra 3500HD, 2022 GMC Sierra 3500HD, 2021 GMC Sierra 3500HD, 2020 GMC Sierra 3500HD, 2019 GMC Sierra 3500HD.
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 48 model years this bulletin names have filed 12,083 complaints with NHTSA since 2015. 14 of them name Exterior Lighting — 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.
The contact owns a 2018 Gmc Sierra Denali. The contact stated that while driving at night, the headlamps failed to adequately illuminate the roadway. The contact stated that there was no improvement in visibility while shifting from low beam to hi beam. The vehicle was not repaired. The manufacturer was notified of the failure.
2018 GMC Sierra · Exterior Lighting · filed with NHTSA Mar 25, 2020
Intermittent issue with entire dash lights and radio lights going either fully out/off or extremely dark. Adjusting dimmer does not correct the issue. Affects driver safety due to acute driver distraction while trying to correct, and disables driver warning lights and all information systems, including towing related warnings…
2019 GMC Sierra 3500HD · Exterior Lighting · filed with NHTSA Feb 26, 2022
Nighttime backing up is to dark to see in the camera. The reverse lights are not bright enough to highlight the area to see correctly. This is a major concern as i almost backed up over my child at night as i could not see them in the camera. Please address with manufacture to resolve the issue.
2023 GMC Sierra · Exterior Lighting · filed with NHTSA Feb 9, 2024
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 exterior lighting
Source: same model, same component group15 other manufacturer communications filed against these GM models under the same component group (exterior lighting), newest first. The eight newest are listed; the rest are on the Chevrolet list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| 07-08-42-006U | Service bulletin | Jun 2, 2025 | This service bulletin provides technicians with information on available BCM calibrations to restore bulb outage detection on vehicles produ… |
| PIE0827 | Service bulletin | Apr 10, 2025 | This engineering informational bulletin is requesting information from technicians to perform the check list provided and contact the engine… |
| 01-08-42-001Q | Service bulletin | Jan 27, 2025 | This service bulletin provides information on Exterior Lamp Condensation and Water Leak Information and Replacement Guidelines. |
| 24-NA-152 | Service bulletin | Nov 9, 2024 | This bulletin offers Information on Intellibeam Inop, Auto High Beam Headlamps, Side Blind Zone Inop, and/or Side Object Detection Inop. |
| PIT6280 | Service bulletin | Nov 8, 2024 | This Preliminary information communicates that a dealer may install the perimeter rocker lighting kit and find that it will not illuminate.… |
| PIT5918B | Service bulletin | Aug 16, 2024 | This Preliminary information communicates an issue where GM Accessory Illuminated Emblem may cause an issue with the left headlight/turn sig… |
| 24-NA-005 | Service bulletin | Jul 17, 2024 | This technical bulletin provides repair information to correct a customer concern of Headlamps Flashing and/or DTC P0606 Set in Lighting Con… |
| PIP5843D | Service bulletin | Mar 6, 2024 | This Preliminary information communicates to the dealers information related to a Malfunction Indicator Lamp (MIL) Illuminated During Cold A… |
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 07-08-42-006T 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 07-08-42-006T 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 07-08-42-006T cover?
The manufacturer filed it against 48 model years across 2 brands (Chevrolet and GMC): 2025 Chevrolet Silverado, 2024 Chevrolet Silverado, 2023 Chevrolet Silverado, 2022 Chevrolet Silverado, 2021 Chevrolet Silverado, 2020 Chevrolet Silverado and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.