Mazda bulletin SA-027-23
What it saysIn-Vehicle Network Malfunction error message. NHTSA’s full summary ↓
Mazda filed this with NHTSA as a service bulletin dated Apr 28, 2023, received May 5, 2023, about the electrical system. It names 14 model years (2021–2023). 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.
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What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationIn-Vehicle Network Malfunction error message. DTC U3000:04 (Telematics communication unit internal malfunction) stored. NOTE: The vehicle does not apply to 09-001/23 because CSP04 is not "OPEN".
Trouble codes it names: U3000
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| SA-027-23 | Service bulletin | Apr 28, 2023 | 10235699 | PDF, 243 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 themA 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 14 model years this bulletin names have filed 645 complaints with NHTSA since 2015. 75 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.
On 14th, 2026, while traveling at approximately 60 mph on the northbound 55 Freeway near the Katella exit, my vehicle suddenly began to shake violently without any prior warning. In response, I attempted to slow down by applying the brakes; however, the speedometer rapidly increased even as I maintained firm pressure on the brake pedal.
2023 Mazda Mazda3 · Electrical System · filed with NHTSA Jan 22, 2026
The contact owns a 2022 Mazda CX-9. The contact stated that the vehicle was being operated with the front driver's side seat warmer activated to the highest heat level. After driving for several hours, the vehicle was parked. While exiting the vehicle, the contact experienced pain in the rear thigh area of each leg.
2022 Mazda CX-9 · Electrical System · filed with NHTSA Apr 1, 2026
The vehicle's Connectivity Master Unit (CMU) / infotainment system has experienced a complete, permanent internal electronic failure, logged by Diagnostic Trouble Code DTC U3000:49 (Control Module Internal Electronic Failure). The main display screen is completely dark at all times and never powers on or responds.
2022 Mazda Mazda3 · Electrical System · filed with NHTSA Aug 11, 2026
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 group162 other manufacturer communications filed against these Mazda models under the same component group (electrical system), newest first. The eight newest are listed; the rest are on the Mazda list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| SA-012-26d | Service bulletin | Sep 18, 2026 | DESCRIPTION Some customers may experience a message "TCU Malfunction. Have the Vehicle Inspected" in the instrument cluster. Additional sym… |
| SA-038-26b | Service bulletin | Sep 10, 2026 | This Service Alert supersedes the previously issued service alert listed below. The changes are noted in Red text. SA-038/26 08/18/26 and 06… |
| SA-015-26e | Service bulletin | Sep 4, 2026 | This Service Alert supersedes the previously issued SA(s) listed below. The changes are noted in Red. SA-015/26 05/27/26, 04/20/26, 04/09/2… |
| SSPE2 MSP67 | Over-the-air update | Aug 22, 2026 | Subject: Announcement of Special Service Program (SSPE2) Ethernet Communication – Over The Air (OTA) Update Concerns and Manufacturer Servic… |
| SSPE1 | Emissions | Aug 20, 2026 | Special Service Program (SSPE1) - 2026 CX-50 Hybrid – Battery Label Concern Mazda Motor Corporation has decided to conduct a Special Service… |
| SA-054-26 | Service bulletin | Aug 20, 2026 | This Service Alert supersedes the previously issued Service Alerts listed below: The changes are noted in Red. Infotainment Reboot With Nav… |
| SA-046-26a | Service bulletin | Aug 20, 2026 | Use this procedure if Body Control Module (BCM) failure occurs due to the laptop rebooting or crashing during a BCM software update with MDA… |
| SA-053-26 | Service bulletin | Aug 19, 2026 | This Service Alert supersedes the previously issued bulletin(s) listed below. The changes are noted in Red text. SA-006/23 01/23/23 DESCRI… |
Quote the number at the service desk. It is what the dealer’s system is keyed on.
Every manufacturer communication NHTSA holds for Mazda, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is Mazda SA-027-23 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 SA-027-23 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 SA-027-23 cover?
The manufacturer filed it against 14 model years: 2023 Mazda CX-30, 2022 Mazda CX-30, 2021 Mazda CX-30, 2023 Mazda CX-5, 2022 Mazda CX-5, 2021 Mazda CX-5 and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.