2021 Mazda Mazda3

My rear differential case cracked, anytime the four wheel drive system was engaged the entire drivetrain would lock up. Luckily we were only on side roads so going less than 30 mph if we had been on the highway when this happened we could have been in an accident or lost control. The dealer did confirm the problem and it was fixed under an extended warranty. There was no warning just all of a sudden a loud bang and all the wheels locked up. I have a copy of the video inspection done at the dealer if there's anyway to send that. I can get a copy of the repair invoice if needed

NHTSA ID

11713224

Incident

Feb 2, 2025

At 31,000 miles the control arm lower ball joints are torn on both lower. They must be replaced. This is a safety hazard. This should not be an issue with low mileage on this car.

NHTSA ID

11695896

Incident

Oct 25, 2025

I was driving when all the sudden there was a loud bang sound. The differential housing cracked. The when awd is demanded the rear diff was was locking up instead of engaging. Luckily we were just on city streets and not on the highway as this rear wheel locking up could cause a crash. Mazda wasn't very helpful with the replacement. Luckily I had a aftermarket warranty but it only paid for a used replacement, which is also failing. I have read lots of stories of this rear differential failure across all types of Mazda's from this era and really wish they would do the correct thing and resolve the problem.

NHTSA ID

11663288

Incident

Jan 31, 2025

Spontaneous loss of power while driving on highway. Check engine light came on. Speed limited by car. Continues to vibrate especially at idle from cold start. Code P0304 intermittently popping up.

NHTSA ID

11656416

Incident

Apr 21, 2025

During the incident, the vehicle exhibited an uncontrollable malfunction—the steering wheel suddenly jerked sharply to the right while accelerating violently, leaving me unable to steer or brake effectively, the car was looking forward. The car ultimately came to a stop upon colliding with a truck parked diagonally in front of me. After impact, I observed that the front tires remained stuck in a turned-right position, with the steering wheel also locked in that position. This was not an isolated event. Multiple reports from Mazda owners describe similar experiences with their vehicles unexpectedly veering to the right and accelerating without driver input. Given these recurring reports and my own experience, I strongly suspect that a manufacturing defect—whether mechanical, electronic, or software-related—may have contributed to this accident.

NHTSA ID

11645615

Incident

Feb 5, 2025

The driver window, upon attempted to be let up, will start to go up then go all the way down, ignoring the function to go up. This is a safety concern, as harsh temperatures and foreign objects are able to enter the vehicle cabin at any time, including driving. The problem has been reproduced by a dealer, and the vehicle is available for inspection upon request. There are no warning indicators for this issue beyond witness the failure occur in real time.

NHTSA ID

11644043

Incident

Mar 13, 2024

When this feature is left on in my vehicle, it will detect curves, vehicles, and objects that are not there, and as a result, will attempt to turn my steering wheel (safety concern). I have had to keep this feature turned off to prevent it wrecking the car, because I could be on a straight road, and it will detect a curve that isn’t there and begin turning the wheel, which could result in a fatal accident if not corrected and disabled by the driver. It is available for inspection upon request. As the dealer has not driven the vehicle, they have not recreated the error, however if anyone were to drive the vehicle, they would be able to observe the malfunction. The dealer has been made aware on many occasions, though they never documented it and only suggested that I turn the feature off, which automatically turns itself on upon ignition. There are no warnings that there is a malfunction; you only know there is an error once an alert pops up thinking you’re missing a curve and attempts to turn your steering wheel though there is no curve. This issue has persisted over the life of the vehicle.

NHTSA ID

11644042

Incident

Jan 26, 2021

The thermostat malfunctioned on this vehicle, resulting in the thermostat remaining open and providing excess coolant to the engine, which in turn damaged internal components of the engine (compromises safety), decreased fuel economy, increased emissions (compromised safety), and decreased the life of the engine within the vehicle. It is available for inspection upon request. The vehicle has been inspected by an independent mechanic and will be inspected by the Mazda dealership in 7 days. There were no prior warnings until the engine malfunction notice appeared, the vehicle began to make jolts and stuttering sounds, and the temperature gauge within the vehicle failed to rise to optimal range. As this occurred while the vehicle was in use (safety concern), though I was pushing the gas there would be delayed response due to improper temperature, which increased the risk for an accident to occur.

NHTSA ID

11644041

Incident

Feb 14, 2025

This Service Alert supersedes the previously issued service alert listed below. The changes are noted in Red text. SA-038/26 06/15/26 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 functions 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

This Service Alert supersedes the previously issued Service Alerts listed below: The changes are noted in Red. Infotainment Reboot With Navigation Card Installed This Service Information is no longer valid. Refer to the following updated Technical Service Bulletins: CX-5 / CX-9: 16-002/23 - UPDATED SOFTWARE RELEASE FOR CONCERNS WITH MAZDA CONNECT INFOTAINMENT SYSTEM (7TH GEN TYPE) Mazda3 / CX-30 (Non-Turbo): 16-008/23 - UPDATED SOFTWARE RELEASE FOR CONCERNS WITH MAZDA CONNECT INFOTAINMENT SYSTEM Mazda3 / CX-30 (Turbo): 16-007/23 - UPDATED SOFTWARE RELEASE FOR CONCERNS WITH MAZDA CONNECT INFOTAINMENT SYSTEM

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 Symptom Troubleshooting DESCRIPTION Customers having MAZDA CONNECT concerns should have their vehicle repaired using the following repair procedure.

This Service Alert supersedes the previously issued bulletin(s) listed below. The changes are noted in Red text. SA-006/23 01/23/23 DESCRIPTION Some customers may complain about the infotainment system and/or the MyMazda App showing incorrect clock and/or tire pressures and/or tire pressure missing. This may be caused by: Incorrect calendar entry (month/day/year) after a battery disconnect Infotainment system software update. BCM TPMS unlearn during vehicle storage or transport. Wheel/Tire change REPAIR PROCEDURE This can be corrected by the customer driving the vehicle for a day or two so that the following will occur.

DESCRIPTION Some customers may complain about SiriusXM Travel Link, Traffic Plus showing expired even though the customer purchased a paid subscription. SiriusXM audio packages do not include SiriusXM Travel Link, Traffic Plus. To get Traffic Plus, the customer must purchase the Infotainment "SiriusXM Traffic Plus with SiriusXM Travel Link (TM)" package.

This bulletin supersedes the previously issued bulletin(s) listed below. The changes are noted in Red text. 01-012/22 10/06/22 DESCRIPTION Some vehicles may exhibit accumulation of dried coolant (1) around the water pipe (2). This is caused by a gap between the housing and pipe due to a press fitting during the manufacturing process. The accumulated coolant is solidified and plugs the gap in high temperature environment and the seepage is stopped and does not progress. This is normal and does not require a part replacement, clean off the dried coolant from around the pipe with a wire brush. REPAIR PROCEDURE 1. Verify the customer concern. 2. If the above condition is experienced, remove the accumulated coolant around the pipe (1) with a wire brush etc. NOTE: Perform the procedure on the vehicle. No need to remove the water pipe and hoses.