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
full bulletin at NHTSA ↗2021 Mazda Mazda3 electrical problems
severe Owners of the 2021 Mazda Mazda3 have filed 5 NHTSA complaints about the electrical at roughly $850 to repair (U.S. federal records, as of August 2026). Source: NHTSA Office of Defects Investigation. See electrical across all vehicles →
Complaints
5
Recalls
0
Avg fix
$850
| Model year | electrical complaints |
|---|---|
| 2017 Mazda3 | 19 |
| 2018 Mazda3 | 28 |
| 2019 Mazda3 | 8 |
| 2020 Mazda3 | 3 |
| 2021 Mazda3 (this page) | 5 |
| 2022 Mazda3 | 4 |
| 2024 Mazda3 | 4 |
2fires
When does it fail?
Of the 5 electrical complaints filed for the 2021 Mazda Mazda3, here's the actual mileage breakdown — failures cluster heaviest at 0-25,000 mi.
0-25k
25-50k
50-75k
75-100k
100-125k
125-150k
150k+
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
What stands out
No new NHTSA electrical complaint has been filed on this vehicle in over 4 years — the issue may be aging out of the active population.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering electrical on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
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)
full bulletin at NHTSA ↗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 e
full bulletin at NHTSA ↗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 t
full bulletin at NHTSA ↗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 -> Info
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
What owners are reporting 1 most recent
The contact owns a 2021 Mazda Mazda3. The contact stated that while driving at various speeds the passenger front side tire was flat which caused the contact to veer to the shoulder. The contact towed the vehicle to the dealer where the tire was inspected as the technician informed the contact that the tire was on backorder and no replacement tire was available. The vehicle then was towed back to…
Had electrical trouble with your 2021 Mazda Mazda3?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the electrical problem on the 2021 Mazda Mazda3?
It's a meaningful issue. 5 complaints have been filed and the failure mode causes operational problems for owners. Repairs average $850.
At what mileage does the electrical typically fail?
Based on the 5 complaints filed, electrical issues most often appear around 1,903 miles. Some report problems earlier; some make it well past 150,000 with no symptoms. Maintenance habits matter — vehicles that received timely fluid services and were not regularly overworked tend to last longer.
What does it cost to fix?
Independent shops typically charge around $850 for electrical repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to electrical?
No active recalls currently cover electrical issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2021/Mazda/Mazda3.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.