2021 Mazda CX-9

The vehicle was parked stationary in the driveway with the engine running for 3-5 minutes with the A/C on. The vehicle then accelerated forward into my garage causing damage. Once I entered the vehicle, both the dash and shifter displayed park. Current TCU system internal failures have been reported from the pulling of data from Mazda.

NHTSA ID

11755863

Incident

Aug 3, 2026

1) What component or system failed or malfunctioned: On 6/12/2026 While drive on the highway with our daughter in the car and we experienced a high speed stall. The engine failed and we lost power. We barely got the car of the highway and coasted into a parking lot. 2) Life threating for Father, Mother and daughter and other drivers on the highway. 3) The Mazda dealer stated they were unable to reproduced problem. The diagnostic report showed few random misfired on two cylinders 2 & 3. Autozone detected codes P0300 with Secondary DTCs U0442-00 4) There car was only inspected by the dealer. The vehicle has not been inspected by Mazda the manufacturer. We requested Mazda to escalate this to the District Service Manger and to open hotline call with Mazda corporate but both of these were denied. All our service has been performed at Mazda dealer, including oil changes. We have always received a video of them working on our car with a detailed summary of what done. We did not receive the video or diagnostic report for this issue. 5) There were no warning lamps, no messages or other symptoms of the problem prior to the failure.

NHTSA ID

11752508

Incident

Jun 12, 2026

This complaint refers to Mazda and it's dealer refusal to properly execute the warranty work under the SSPD5 Valve Stem Seal Class Action Campaign and does not follow the Court's approval of the final Settlement Agreement. I assert that Mazda and it's dealer are not following the SSPD5 repair procedures. 1. I have documentation and complaints going back to Dec-2023 with this particular dealer that I have experienced low level oil consumption within the 7,500 mile oil change interval. The dealer did not detect oil leaks in any of the engine systems. 2. I presented the vehicle to the dealer with the Engine Oil Level Warning Light illuminated. The Diagnostic Trouble Code (DTC) P250FF:00 should be stored in the vehicle memory. 3. The vehicle had 50,501 miles and was within the original 60 month limited powertrain warranty. 4. The dealer refused to conduct the valve stem seal repairs until an oil consumption test was run. The dealer claims that because I had another service center (note that I use full synthettic oil that meets Mazda oil specifications) conduct the most recent oil change at 43,738 miles (note within the 7,500 oil change interval and the 1 year time window) that the dealer would require an oil consumption test. I assert that this is not required per the class settlement agreement and the SSPD5 repair procedures that Mazda sends to all of its dealers. 5. I researched the available documentation that it's available through the NHTSA.gov. The language in these documents is very clear. 6. SSPD5 Valve Stem Class Action Campaign, Repair Procedure 6-12-2024: a. "The DTC250 is not required to be present for valve stem replacement." b. "Customer complaint of oil consumption...OR Low Oil Light OR DTC250 follow the flow chart." c. Flow chart says "Replace the exhaust valve stem seals by following TSB 01-003/24" if no previous warranty work done. 7. SSPD5 updates on 8-6-25 and 4-28-26: a. Refer to page 4, DTC250 is NOT required to be presented (it is noted in RED).

NHTSA ID

11749820

Incident

Jul 6, 2026

Check engine light comes on and error P0303 comes on. Had an independent mechanic do the following and after each one, error P0303 still came on 1. Swap the ignition coils from 2 to 3 2. Swap spark plugs from 2 to 3 3. Swapped injectors 4. Compression test 5. Leak down test 6. Changed the spark plug, coil and injectors 7. Looked for vacuum leaks. Mechanic believes that it is related to the cracked cylinder head in the recall, MC-10232269-0001.pdf. My vehicle is just outside of the recall range and has 87k miles on it. Other research online shows other people with the same vehicle and similar milealge are also having this problem.

NHTSA ID

11745150

Incident

Jun 18, 2026

Backup camera shows three to four feet before red collision line is not accurate causing severe damage to my garage door.

NHTSA ID

11704278

Incident

Dec 8, 2025

My vehicle is part of Mazda's 2021-2022 Mazda Valve Stem Seal Settlement. The dealership had yet to call me in for the repair of said valve seal repair as I was on a list. The settlement is suppose to extend out the powertrain warranty on the vehicle 2 years/24,000 to 7 years/84,000. My vehicle has 60,083 miles on it. One of the cylinders on my vehicle lost compression. The dealership and Mazda both say they will not cover the cost for repair as they only are covering things in the powertrain relate to oil consumption. The cylinders are part of the powertrain and carbon buildup from excessive oil burning because of the defective seal causes valve damage or sticking which will cause compression loss. Mazda is actively denying what they agreed to in the settlement and costing people money for repairs that should be covered.

NHTSA ID

11665046

Incident

May 22, 2025

My MazdaCx9 engine consumes (burns) an excessive amount of oil, necessitating frequent top-offs between oil changes.This issue started after the first oil change and continued since then.

NHTSA ID

11632117

Incident

Sep 11, 2024

On [XXX], [XXX], [XXX] I was driving on an interstate highway with a 65 mph speed limit with no warning and received the following codes which slowed the vehicle to the limp mode. 1) Smart Brake Support and Forward Obstruction Warning 2) Activsense system malfunction 3) Front Radar Sensor Malfunction 4) Engine Malfunction 5) Dynamic Stability Control Malfunction I reported all three incidents to the dealer and no codes were left and the dealership had no solution for the problem. They suggested dirt, sunlight, or blowing debris caused it, but that was not the case. Luckily the first two incidents happened with little or no traffic around but the third was during rush hour and almost caused a major accident trying to get off the highway. I shut the car off, restarted and the problem resolved no lights left on or warnings appearing all three times. Contacted Mazda several times and all representatives at the dealership and California Headquarters claim no knowledge of this happening. I found a few others reporting the same issue and wanted to report this. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11627970

Incident

Sep 3, 2024

This Service Alert supersedes the previously issued SAs listed below. The changes are noted in Red text. SA-017/25 12/16/25, 09/08/25, 07/14/25, 05/15/25 and 03/21/25 DESCRIPTION Mazda Connect Frequently Asked Questions (FAQ) Index General Questions MAZDA CONNECT Indication Setup and Getting Started Dealer Processes Registration / Enrollment / Take-Over Customer Subscription Status WI-FI General Informatio Opening the TCU Communication Line WI-FI How-To Conditions for Remote Engine Start Will Not Function WI-FI Trial Period Conditions for Remote Engine Start Function Will turn engine OFF Interacting With The App TCU Communication Line Status Service Issues Educational Videos Troubleshooting Resources MyMazda App Error Codes Customer Opt-Out

This SA supersedes the previously issued SA(s) listed below. The changes are noted in Red. SA-061/25 12/17/25 DESCRIPTION If you encounter any type of electrical concern (e.g, dead battery, engine no start, DTC(s) stored...), interview the customer before proceeding with normal MGSS diagnosis by asking if any aftermarket devices have been installed. Aftermarket devices may be the cause of the electrical concern. Below are a few examples of unusual electrical concerns caused by aftermarket devices. Examples: 1. Devices connected to the DLC-2 (battery discharge/DTC stored) 2. Devices plugged into the 12V outlet 3. GPS tracking device (engine no start/battery discharge) 4. Dash cam (DTC stored) 5. Non-certified USB cable (Apple Carplay™/ Android Auto™ will not connect) 6. Over-sized wheels/tires (incorrect GPS location) 7. DTC C0023:14 8. Decorative trim and/or cover on the START/STOP ENGINE button Example 1: Some electrical devices connected to the DLC-2 connector by insurance or mobile phone companies may cause: Battery discharge. The device may disrupt the CAN system battery saver mode. • IDS/MMDS will not communicate with the vehicle due to poor DLC-2 connection. The aftermarket device may cause DLC-2 female terminals to spread open.

This bulletin supersedes the previously issued bulletin(s) listed below. The changes are noted in Red. 09-012/21 12/13/21, 06/10/21 and 04/27/21 DESCRIPTION Some customers may experience all of following symptoms: The door lock/unlock operation will not work using the remote transmitter button. 1. The door lock/unlock operation will not work using the door lock/release touch sensor. 2. The engine will not start using the ignition switch. 3. The transmitter operates by itself. 4. The key battery drains faster than usual. 5. Symptoms 1-3: This may be caused when excess load is applied to the remote transmitter, deforming the electrical terminals and creating poor contact with the battery. To eliminate this concern, the structure in the remote transmitter has been modified to reduce the deformation of the electrical terminals. Symptom 4-5: This may be caused when excessive load is applied to the remote transmitter, creating a gap around the gasket where moisture enters and corrodes the circuit board which in turn drains the key battery faster than usual. To eliminate this concern, the thickness of the case wall on the gasket mounting surface has been increased and the bonding strength of the components has been improved to prevent deformation. REPAIR PROCEDURE • If the battery is bad or installed incorrectly, replace the battery and/or install it correctly. • If the remote power saving function is off and the battery is good and installed correctly, replace the defective remote transmitter with a modified one according to the instructions on MGSS (IMMOBILIZER SYSTEM-RELATED PARTS PROGRAMMING). NOTE: DO NOT replace other remote transmitter(s) for the vehicle if they not experiencing an issue.

This SA supersedes the previously issued bulletin(s) listed below. The changes are noted below in Red. SA-027/26 04/16/26 DESCRIPTION The Mazda DCA-8000 is required for all warranty battery testing. If the Mazda DCA-8000 is not used, incorrect battery testing may result in unnecessary battery replacement. Use the following test procedures in this Service Bulletin to test Mazda vehicle batteries and to generate a Warranty Code. NOTE: A Warranty Code is required for warranty claim submission Battery Identification (Mazda batteries have 2 rating types) 1. JIS (Japanese Industrial Standard): JIS codes are six-digit alpha-numeric markings (excluding i-STOP batteries e.g. Q-85, S-95) molded into the top of the battery to identify a battery by the capacity (amps), dimensions, and battery terminal type. Vehicles manufactured in Japan come from the factory with a JIS rated battery. NOTE: Replacement batteries may use a CCA rating. If so, use the CCA rating listed on the battery. REPAIR PROCEDURE 1. Perform appropriate repair to vehicle. If needed, use the Battery Diagnostics of the DCA-8000 to test the charging and starting systems by following the on-screen instructions for entering the appropriate information. Refer to the Mazda DCA-8000 Instruction Manual for more information.

This Service Alert supersedes the previously issued SA listed below. The changes are noted in Red text. SA-012/25 10/06/25, 08/21/25, 05/15/25 and 02/27/25 DESCRIPTION Customers having MAZDA CONNECT concerns should have their vehicle repaired using the following repair procedure. REPAIR PROCEDURE NOTE: Before proceeding: Document the vehicle's current MAZDA CONNECT CMU software version. • 2019-2022 Models - Go to TSB 16-003/23 and confirm the CMU Serial Number is not within the affected range. • Document customer device Brand/Model/Model Number/software version on the repair order. • Confirm that the Connectivity Master Unit (CMU) is updated to the latest software version. Go to MGSS -> Infotainment -> MAZDA CONNECT Updates ○ • If possible, complete the Microsoft Forms Questionnaire. Go to MGSS -> Infotainment -> MAZDA CONNECT Questionnaire.

DESCRIPTION Some customers may complain about any of the following: 1. Infotainment Center Display does not provide the Authorization Code (OTP) during the MyMazda App Connected Vehicle enrollment. 2. Remote function(s) inoperative. Engine Start / Stop Door Lock / Unlock Lights ON / OFF Climate Control 3. MAZDA CONNECT connected vehicle reception strength icon shows "X" or " ". Index MAZDA CONNECT 2 Center Display Status Icon MAZDA CONNECT 3 Center Display Status Icon Remote Engine Start Will Not Function Remote Engine Start Function Will turn engine OFF Customer Subscription Status TCU Communication Line Status