GM bulletin 22-NA-187
What it saysThis informational bulletin advises the tech to inspect the transfer case motor electrical connectors for possible damage or corrosion that might be caused by a damage grommet inside the electrical connector. NHTSA’s full summary ↓
GM filed this with NHTSA as a service bulletin dated Aug 22, 2023, received Feb 7, 2023, about the electrical system — 2 documents under this number. It names 42 model years across Chevrolet, GMC and Cadillac (2019–2023). 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 · Cadillac.
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What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationThis informational bulletin advises the tech to inspect the transfer case motor electrical connectors for possible damage or corrosion that might be caused by a damage grommet inside the electrical connector.
Trouble codes it names: C05FB C11B9 C15AB C15C1 all 4 read from the document itself; NHTSA’s summary names none
Documents filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| 22-NA-187 | Service bulletin | Aug 22, 2023 | 10242263 | PDF, 85 KB |
| 22-NA-187 | Service bulletin | Jan 19, 2023 | 10231427 | PDF, 65 KB |
What the document itself lists
The manufacturer titles it “Information on Service 4WD Light Intermittently Displays On the Drivers Information”.
Part the bulletin names
| Part number | Description | Qty | Find it |
|---|---|---|---|
| 19369184 | Bulletin No.: 22-NA-187 August, 2023 Page | 1 | eBay Motors → |
Labour operation and the time the manufacturer allows
| Operation | Description | Time |
|---|---|---|
| 5486338 | Transfer Case Electrical Connector inspection and Replacement | 1.5 hrs |
Read by machine from the document NHTSA serves (3 pages), read Sep 30, 2026. A part number is shown only where it matches GM’s own catalogue shape, an operation only with its code and time, and a description only where the reader got it whole; anything it could not settle is left out, and the PDF is the record. Times are the manufacturer’s warranty allowances, not a quote. Listings and prices on eBay Motors are the seller’s.
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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 21 model years
GMC 17 model years
Cadillac 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 42 model years this bulletin names have filed 11,016 complaints with NHTSA since 2015. 4,276 of them name Power Train, 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.
On the 2019 Chevrolet Silverado, the 106 owners who gave an odometer reading for Power Train reported it at a median of 15,000 miles. That figure is one model year’s, not the whole range this bulletin covers — medians from different model years are not averaged.
Sudden jerk power train and deceleration while driving and towing 5th wheel, immediate loss of power and could have been catastrophic. GM has a known defect that requires immediate attention and investigation to affirm this is a broad national problem with the Allison 10 speed 10L1000 transmission, specifically the defective transmission…
2023 Chevrolet Silverado 2500HD · Power Train · filed with NHTSA Jul 8, 2025 · ODI 11671999
The valve body assembly is not letting it to shift right when driving from 50mph to 60 mph it has a clunking noise I have it replaced and is still not working correctly GM knows there is a problem with the 10 speed transmissions I have a 2023 3500 diesel with the same problem as the recalls on the 2020 to 2022 years It is doing the same…
2023 Chevrolet Silverado 3500HD · Power Train · filed with NHTSA Jun 27, 2026 · ODI 11746880
There is an issue that is causing the batteries to die. This in return causes the Vehicle to go into Limp home mode with no warning. The "issue" was supposed to be resolved by the Dealer in March 2022. The resolution was that one battery was bad. The vehicle is equipped with two batteries. Each of which is sufficient to run the vehicle.
2020 GMC Sierra 2500HD · Power Train · filed with NHTSA Jan 3, 2023 · ODI 11499881
In depth: 2023 Chevrolet Silverado transmission and drivetrain problems → · 2023 Chevrolet Silverado electrical problems → · 2022 Chevrolet Silverado transmission and drivetrain problems → · 2022 Chevrolet Silverado electrical problems →
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 group311 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 |
|---|---|---|---|
| N262565450 | Service campaign | Oct 26, 2026 | Customer Satisfaction Program. Certain vehicles listed above may have a condition in which remanufactured high voltage battery packs were b… |
| N252529080 | Service campaign | Apr 1, 2026 | Service Update. Certain vehicles listed above may be missing a high voltage header plug on the RESS battery pack drive motor connector. Dea… |
| N252515590 | Service campaign | Jan 27, 2026 | Certain vehicles listed above, may have a condition in which the body-to-chassis ground strap may be corroded. Dealers will replace the grou… |
| 18-NA-180 | Service bulletin | Sep 4, 2025 | This Warranty Administration service bulletin provides Lithium-Ion battery Exchange Process and Transaction Submission information. |
| 25-NA-021 | Service bulletin | Jun 7, 2025 | This technical bulletin provides repair information to correct a customer concern of Radio Software Update W23E-178.1.2-M174-SQBR6-93.3. |
| 25-NA-153 | Service bulletin | Jun 5, 2025 | This informational bulletin provides Information on Rear Upper Body Structure Auxiliary Lamp Will Not Turn ON. |
| 22-NA-083 | Service bulletin | May 17, 2025 | This service bulletin provides Requirements for Replacement of the Dual Mode Cord Set Under Warranty. |
| 25-NA-131 | Service bulletin | May 17, 2025 | This Service bulletin provides information on the heated seats warming up when the vehicle is started but soon cooling off and the heated se… |
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 Cadillac, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is GM 22-NA-187 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 22-NA-187 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 22-NA-187 cover?
The manufacturer filed it against 42 model years across 3 brands (Chevrolet, GMC and Cadillac): 2023 Cadillac Escalade, 2022 Cadillac Escalade, 2021 Cadillac Escalade, 2020 Cadillac Escalade, 2023 Chevrolet Silverado, 2022 Chevrolet Silverado and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.