Mazda bulletin 09-027-26
What it saysDESCRIPTION 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 successfully on the next attempt. NHTSA’s full summary ↓
Mazda filed this with NHTSA as a service bulletin dated Sep 29, 2026, received Oct 1, 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 CX-70 and CX-90 PHEV vehicles may fail to start (enter READY mode) in cold weather, but the vehicle can often be started successfully on the next attempt. This may occur when leakage current between connector terminals causes the MAIN Relay to be falsely detected as ON. As a result, the Battery ECU may incorrectly determine the relay status, preventing READY mode activation and resulting in a no-start condition. One or more of the following DTCs may be stored: P0AB9, U0100, U0110, and U0115 and multiple warning lights may also turn on. This is caused by corrosion of the connector terminals on the 3002-411 connector in the luggage compartment from water. To eliminate this concern, urethane has been added around the connector to help prevent water from reaching the connector terminals. REPAIR PROCEDURE 1. Verify the customer concern. 2. Diagnose and repair the vehicle according to the following steps. NOTE: The following procedure uses a heat shrink tube with solder. (1) Connect wire to wire with heat shrink tube. (2) Form a loop at the end of wire to create a passage for the other wire.
Trouble codes it names: P0AB9 U0100 U0110 U0115
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| 09-027-26 | Service bulletin | Sep 29, 2026 | 11037628 | PDF, 755 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 547 complaints with NHTSA since 2015. 172 of them name Engine, 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.
I own a 2026 Mazda CX-90 hybrid with approximately 13,000 miles. The vehicle began making a grinding noise while driving, which has progressively worsened over time. It has since developed a hard knocking noise accompanied by noticeable vibration when the vehicle shifts gears. This knocking occurs during normal in-town driving.
2025 Mazda CX-90 · Engine · filed with NHTSA Jul 14, 2026
My boyfriend and I rented the car from Hertz Car Rental in on Labor Day weekend. Within moments of driving the car off the lot, the safety camera system stopped working and the lights came on saying they weren’t working. The touch screen also started glitching and intermittently working but we didn’t think too much about it.
2026 Mazda CX-90 · Engine · filed with NHTSA Sep 20, 2026
Instrument cluster will reboot during braking at random times. All warning lights turn on, gauges go to zero and front wipers are set off. This happens for 1-3 seconds. Mazda replaced instrument cluster but only made issue worsen they said it’s safe to drive but very distracting especially when turning onto busy roads.
2026 Mazda CX-90 · Electrical System · filed with NHTSA Jun 10, 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 group123 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-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… |
| SA-050-26 | Service bulletin | Aug 7, 2026 | DESCRIPTION Some vehicles may continue to display the recall notification "IMPORTANT NOTICE. VIEW VEHICLE STATUS MONITOR FOR DETAILS" on the… |
| SA-012-26c | Service bulletin | Aug 7, 2026 | This Service Alert supersedes the previously issued SA(s) listed below. The changes are noted in Red. SA-012/26 04/17/26, 03/04/26 and 02/2… |
| SA-049-26 | Service bulletin | Aug 6, 2026 | DESCRIPTION For CX-70 PHEV (SC) models, the SC specification includes ECU modifications to extend electric driving range. The BECM… |
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 09-027-26 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 09-027-26 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.
Which vehicles does 09-027-26 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.