GM bulletin PIT6137
What it saysThis Preliminary information communicates an issue with clearing DTC: C15DD and how to rest the average release time to clear DTC. NHTSA’s full summary ↓
GM filed this with NHTSA as a service bulletin dated Mar 22, 2024, received Apr 15, 2024, about the service brakes. It names 8 model years across Chevrolet and GMC (2020–2023). 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 · GMC.
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What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationThis Preliminary information communicates an issue with clearing DTC: C15DD and how to rest the average release time to clear DTC.
Trouble codes it names: C15DD
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| PIT6137 | Service bulletin | Mar 22, 2024 | 10253106 | not found |
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
GMC 4 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 8 model years this bulletin names have filed 552 complaints with NHTSA since 2015. 65 of them name Service Brakes — 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.
My vehicle inadvertently locks the rear tires at highway speeds and then releases and drives. In some instances it may brake several times causing the tires to burn rubber for a short distance causing rear traffic to either swerve to avoid rear ending me and in a couple instances causes the rear following traffic to abruptly change lanes…
2020 GMC Sierra 2500HD · Service Brakes · filed with NHTSA Mar 29, 2024 · ODI 11580026
Electronic trailer brake controller when using disconnects and reconnects turning trailer brakes on and off creating an unsafe situation by never knowing if trailer brakes are going work. Dealer states no problem found with controller and changed trailer plug. Not correcting issue. Tried 2 other trailers same issue occurred.
2022 Chevrolet Silverado 2500HD · Service Brakes · filed with NHTSA Aug 13, 2024 · ODI 11608142
The contact owns a 2021 Chevrolet Silverado 2500. The contact stated while driving at various speeds and depressing the brake pedal, there was an abnormal squeaking sound coming from the rear of the vehicle. The dealer was not notified of the failure and informed the contact that the brakes needed to be replaced.
2021 Chevrolet Silverado 2500HD · Service Brakes · filed with NHTSA Mar 9, 2023 · ODI 11511007
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 service brakes
Source: same model, same component group13 other manufacturer communications filed against these GM models under the same component group (service brakes), newest first. The eight newest are listed; the rest are on the Chevrolet list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| 24-NA-048 | Service bulletin | Feb 6, 2025 | This engineering informational bulletin is requesting information from technicians to perform the check list provided and contact the engine… |
| PIT5828D | Service bulletin | Jan 9, 2025 | This Preliminary Information communication provides information to the technician about customers that may request the factory Integrated Tr… |
| 23-NA-149 | Service bulletin | Oct 26, 2024 | This technical bulletin provides a procedure to correct the condition of Trailer Brake Disabled and/or DTC C1114 Stored During Pulling a Tra… |
| PIT6212B | Service bulletin | Oct 25, 2024 | This Preliminary information communicates an issue with the Hydrastar Electric Over Hydraulic trailer brake system causing a voltage spike i… |
| 22-NA-092 | Service bulletin | Oct 22, 2024 | This informational bulletin provides an optional repair using a different set of brakes that may correct the customers concern of Early Brak… |
| PIT5282G | Service bulletin | Sep 13, 2024 | This Preliminary Information communication provides information to the technician that a customer may request the factory Integrated Trailer… |
| PIT6212A | Service bulletin | Sep 11, 2024 | This Preliminary information communicates an issue with the Hydrastar Electric Over Hydraulic trailer brake system causing a voltage spike i… |
| N232414840-02 | Service campaign | Aug 9, 2024 | Customer Satisfaction Program. On certain vehicles equipped with Integrated Trailer Brake (RPO JL1), if the trailer battery is charged to 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 PIT6137 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 PIT6137 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 PIT6137 cover?
The manufacturer filed it against 8 model years across 2 brands (Chevrolet and GMC): 2023 Chevrolet Silverado 2500HD, 2022 Chevrolet Silverado 2500HD, 2021 Chevrolet Silverado 2500HD, 2020 Chevrolet Silverado 2500HD, 2023 GMC Sierra 2500HD, 2022 GMC Sierra 2500HD and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.