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Service bulletins for the 2020 Mazda Mazda3

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

726 on file from NHTSA, as of 2026-10-19.

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Only bulletins with component: Electrical system are shown. Show all

Bulletins, newest first
09-003-20-36712020-01-23. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. In accordance with Federal regulations, follow the procedure listed below when replacing a speedometer. NOTE: Tampering with a motor vehicle odometer is strictly prohibited by Federal, and State laws. It is the dealer’s responsibility to comply with Federal, State, and local laws concerning odometer and related documentation requirements when providing a repair or replacement. • Mazda vehicles are manufactured with tamper-proof speedometers. • When a speedometer is replaced, the new speedometer will read zero (0) miles. • This procedure is extremely important to accurately represent actual vehicle mileage. • Prior to speedometer removal, complete the information required on the “Speedometer Replacement Label”. Labels can only be ordered through Mazda eStore. • In an effort to achieve a higher level of Customer Experience and retain the value of Mazda’s vehicles, MNAO Warranty Operations is allowing all Mazda dealers to utilize a third party, SPECMO Enterprises, Inc., for Instrument Panel Cluster (IPC) odometer setting service. With the use of SPECMO’s services, it is possible that the odometer will be set between 10 to 31 miles over the odometer mileage at the time of replacement for both warranty and customer pay repairs. Please make sure that the customer is aware that there may be a slight variance to the odometer, in which case the customer may have to accept the slightly higher mileage. Since odometer setting service is not part of the warranty repair, it is not warrantable nor required, but optional. However, Mazda Warranty policy provides after- warranty assistance (AWA) or DSA that can be utilized to cover this service expense.
MT-004-192019-11-24. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT; ELECTRICAL SYSTEM. Some customers may complain about: • Intermittent engine no start • Instrument cluster red security indicator light ON • Engine Start/Start Button Amber indicator light flashing • Battery discharge • Electrical relay buzzing noise • DTC B13D3:94 (Communication error with remote transmitter) stored.This may be caused by: • A key in a purse near a cell phone. The cell phone radio waves may interrupt the immobilizer system. • An aftermarket cell phone charger. The charger may produce electrical noise that interrupts the immobilizer system. • An aftermarket GPS tracker. Some aftermarket devices that are wired to the vehicles’s wiring harness may create unusual electrical symptoms.
SA-046-192019-11-21. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT. On the 2019 Mazda3 (BP) and and all 2020 Mazda vehicles (except CX-3), the CR2032 button cell battery is required for the new type remote transmitter. If it is mistakenly replaced with the conventional CR2025 used in the previous type remote transmitter, it may cause a malfunction. Verify the button cell battery type before replacing it.
SA-019-192019-11-21. Service bulletin. EQUIPMENT; FORWARD COLLISION AVOIDANCE: SENSING SYSTEM: RADAR; ELECTRICAL SYSTEM; EQUIPMENT ADAPTIVE/MOBILITY. Some vehicles may experience M-MDS (MDARS) showing the front radar dynamic aiming is incomplete, although the procedure is completed. This is caused by faulty front radar software logic and a mass production change is planned. If the screen below is displayed after the front radar dynamic aiming is performed, check the vehicle using the following inspection procedure.
SA-045-192019-11-01. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. Currently, Mazda does not have a way to cut the auxiliary keys for the new style remote transmitter as they use a different key code than the previous transmitter key. Follow the repair procedure if one or both auxiliary keys are lost:
DRW262019-10-30. Service bulletin. EQUIPMENT; EQUIPMENT ADAPTIVE/MOBILITY; LATCHES/LOCKS/LINKAGES; ELECTRICAL SYSTEM. Outline of concern: On certain subject vehicles, it is possible the following concerns may happen when the connectivity service is available. 1. The hands-free capability does not work properly due to a communication error between CMU (Connectivity master unit) and the microphone. 2. The communication failure happens between the TCU (Telematics Communication Unit) and connectivity server due to improper software of the TCU. 3. Door lock operation will work even though the key fob is inside of the vehicle. Outline of repair: Reprogram TCU and C-BCM with modified software, using a specific MDRT3 tool.
SA-044-192019-10-30. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING. The "FORCED IGNITION ON PROCEDURE" was made available to dealers through this service alert.
SA-043-192019-10-30. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. On 7th generation vehicle (2019-2020 Mazda3 (BP) and 2020 CX-30 (DM)), when the door is opened/closed with the ignition switch off, the battery current is approximately 7A, which is three times larger than previous generation models (2.5A on Mazda6 (GL)). In addition, after the door is closed, a 6A current continues for 6 minutes on 7th generation vehicles. This is why frequent door operation in the show room may result in low battery voltage.To avoid a drained battery, especially when the vehicle is displayed for customers in a show room (with door operation being more frequent and battery consumption being larger), it is highly recommended to perform more frequent battery maintenance than for previous generation models.
SA-042-192019-10-04. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM; EQUIPMENT ADAPTIVE/MOBILITY. Customers having MAZDA CONNECT concerns should have their vehicle repaired using the following repair procedure. NOTE: Before proceeding: Confirm that the Connectivity Master Unit (CMU) is updated to the latest software version. Go to MGSS - Infotainment - MAZDA CONNECT Updates, Confirm that the customers device is updated to the latest software version. Apple Carplay/Android Auto FAQ, go to SA-001/19.
SA-010-19j2019-09-23. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; VISIBILITY; EQUIPMENT; ELECTRICAL SYSTEM; LANE DEPARTURE: BLIND SPOT DETECTION; WHEELS. 2019-2020 MAZDA3 SERVICE CAUTIONS FOR NEW AND REVISED FEATURES. The 2019-2020 Mazda3 has new and revised features that are different from previous models, and may be difficult to understand. This Service Alert provides valuable information to support potential dealer and customer concerns. Index: PDI fuse, Apple CarPlay / Android Auto Install Kit, Blind Spot Monitoring System (BSM), Front Wiper Service Caution, i-ACTIVSENSE Switch, Traffic Sign Recognition (TSR), MAZDA CONNECT Power Function, MAZDA CONNECT Center Display View, In-Vehicle Digital Owner's Manual, Navigation System, SIRIUSXM Data Service, Power Door Locks, Auxiliary Key, Transmitter Battery Saving Function, Keyless Entry Using Auxiliary Key, Rear Door Child Safety Locks Operation, Link Seat & Climate Control Temperatures, Seat Warmer Turns OFF, Electric Parking Brake (EPB), A/C Air Temperature Is Not Cold, Tire Pressure Monitoring System (TPMS), Condition Based Maintenance, M-MDS (MDARS), Part Replacement.

The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.