Mazda bulletin SA-030-26
What it saysDESCRIPTION Some vehicles may experience one or more of the following DTCs with the Hybrid system warning light on. NHTSA’s full summary ↓
Mazda filed this with NHTSA as a service bulletin dated Apr 22, 2026, received May 4, 2026, about the electrical system. It names 5 model years (2024–2026). 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 communicationDESCRIPTION Some vehicles may experience one or more of the following DTCs with the Hybrid system warning light on. This may be caused by an issue with the sub battery located under the passenger floor. P143B Backup power supply system: Sub battery power supply low input. • U3008:01 BPS Backup power supply unit input/output circuit over-current/voltage malfunction. • U3003:17 BPS The output voltage sensor in the backup power supply unit detects that the voltage is standard or more. • U04C0:00 PCM Backup power supply unit internal malfunction. • REPAIR PROCEDURE 1. Remove the sub battery according to the instructions on MGSS. CX-90 (LEAD ACID BATTERY (SUB) REMOVAL/INSTALLATION) • CX-70 (LEAD ACID BATTERY (SUB) REMOVAL/INSTALLATION) • 2. Test the battery's voltage using a digital voltmeter (DVOM) and record the result on the warranty claim. NOTE: The DCA 8000 does not accurately test this small battery. You DO NOT need the DCA 8000 test printout for a warranty claim. 3. Install a new sub battery.
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| SA-030-26 | Service bulletin | Apr 22, 2026 | 11032023 | PDF, 163 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 5 model years this bulletin names have filed 587 complaints with NHTSA since 2015. 93 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.
While driving the vehicle, the entire instrument cluster repeatedly turns off and "reboots". All warning lights appear, gauge needles drop to zero, then it all turns back on to normal operation. This has happened intermittently since purchasing the vehicle new. Currently has 1150mi
2026 Mazda CX-90 · Electrical System · filed with NHTSA Oct 30, 2026 · ODI 11774709
Hybrid system electrical leakage. Literally makes the car unusable. Dozens of examples on both Reddit and Facebook
2024 Mazda CX-90 · Electrical System · filed with NHTSA Feb 18, 2024 · ODI 11572606
In depth: 2024 Mazda CX-90 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 group125 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 |
|---|---|---|---|
| 09-027-26 | Service bulletin | Sep 29, 2026 | DESCRIPTION Some CX-70 and CX-90 PHEV vehicles may fail to start (enter READY mode) in cold weather, but the vehicle can often be started su… |
| 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-042-26a | Service bulletin | Sep 17, 2026 | Mazda Connected Services - Frequently Asked Questions (FAQ) This Service Alert supersedes the previously issued SAs listed below. The chang… |
| SA-041-26a | Service bulletin | Sep 11, 2026 | DESCRIPTION If you encounter any type of electrical concern (e.g, dead battery, engine no start, DTC(s) stored...), interview the customer b… |
| 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-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… |
| SA-039-26a | Service bulletin | Aug 19, 2026 | This Service Alert supersedes the previously issued SA(s) listed below. The changes are noted in Red text. SA-039/26 06/15/26 Mazda Connect… |
| SA-051-26 | Service bulletin | Aug 15, 2026 | This Service Alert supersedes the previously issued SA(s) listed below. The changes are noted in Red. SA-076/24 10/22/24 DESCRIPTION This Se… |
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-030-26 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-030-26 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 Mazda warranty extension on file lists the ones Mazda has filed.
Which vehicles does SA-030-26 cover?
The manufacturer filed it against 5 model years: 2026 Mazda CX-70, 2025 Mazda CX-70, 2026 Mazda CX-90, 2025 Mazda CX-90, 2024 Mazda CX-90. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.