Service bulletin 04-003-21-3810

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.

The communication, as NHTSA indexes it (as of 2026-10-19)
Type	Service bulletin
NHTSA id	10198569
Published by NHTSA	2021-06-29
Manufacturer's number	04-003-21-3810
Manufacturer's date	2021-06-17
NHTSA component	SERVICE BRAKES; EQUIPMENT ADAPTIVE/MOBILITY

NHTSA's summary

Some customers may complain about the following braking concerns when coming to a stop while following a vehicle ahead using Mazda Radar Cruise Control with Stop and Go function (MRCC). Harder braking at slow speeds just before a complete stop. Before coming to a complete stop, the vehicle creeps towards the vehicle ahead and Depress Brake Pedal warning message may appear in the instrument cluster. This is caused by improper control software of the DSC HU/CM. To eliminate this concern, the control software of the DSC HU/CM has been modified.

The document

The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.

Components

Brakes, Equipment and accessories

Vehicles listed
MAZDA CX-30	2020, 2021
MAZDA MAZDA3	2019, 2020, 2021

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Recalls for the same vehicles and component
2020264	2020-06-12. Brakes
20V346000	2020-06-12. SERVICE BRAKES, HYDRAULIC:FOUNDATION COMPONENTS:DISC:CALIPER
2019649	2019-12-19. Brakes

A recall listed here may apply to some of the same vehicles. Only the manufacturer can say whether it applies to one vehicle.

Other bulletins for the same vehicles and component
SA-029-26	2026-05-05. Service bulletin. This Service Alert supersedes the previously issued SA listed below: The changes are noted in Red. SA-011/24 02/12/24, 06/06/24, 07/29/24 DESCRIPTION Mazda has developed factory recommended scheduled maintenance services that support all major vehicle systems. Mazda recommends dealers follow the scheduled maintenance tables as cited in the vehicle-specific workshop manual or owner's manual. Services performed outside of Mazda's factory scheduled maintenance are not recommended. These services are unnecessary and create unneeded expenses for your customers. SCHEDULED MAINTENANCE Refer to the applicable Workshop Manual or Owner's Manual for vehicle -specific manufacturer scheduled maintenance. Workshop Manual - Refer to section 00-00 SCHEDULED MAINTENANCE. Owner's Manual - Refer to section 8 Maintenance and Care. b. Note: Please refer to the information below outlining the services not included in Mazda's Factory Scheduled Maintenance: IMPORTANT: Recommending fluid flushes when not necessary can lead to customer confusion and dissatisfaction. Fluid flushing for preventive maintenance purposes is strongly discouraged, unless otherwise specified in a published procedure (Owner’s Manual, Workshop Manual, Technical Service Bulletin, etc.).
SA-055-25	2025-12-05. Service bulletin. Some vehicles exhibit brake related concerns such as brake noise, brake judder or brake dragging. If you encounter a customer complaint for any one of these symptoms, refer to the following information to understand why symptoms may occur, and to better assist the customer in resolving their specific brake concern. NOTE: Before following this Service Alert repair procedure, ensure published TSBs in MGSS have been completed per model year.
SA-016-24c	2024-11-04. Service bulletin. Some vehicles exhibit brake related concerns such as brake noise, brake judder or brake dragging. If you encounter a customer complaint for any one of these symptoms, refer to the following information to understand why symptoms may occur, and to better assist the customer in resolving their specific brake concern.
SA-007-24b	2024-10-04. Service bulletin. This information will give you the necessary knowledge to respond to customers concerns of Smart Brake Support (SBS) unintended braking. By educating the customer on the system operation, it should reduce their anxiety or distrust of the vehicle.
04-001-24b	2024-10-04. Service bulletin. Symptom 1: Some customers may complain about hearing a grinding noise and/or vibration occur when applying the brake. This is due to rust on the rear brake disc plate. The brake pad has insufficient disc-rust prevention performance, resulting in the disc plate rusting. To eliminate this concern, the pad material has been improved to prevent rust on the disc surface. Symptom 2: Some vehicles may exhibit a squeal noise from the rear brakes when braking lightly while driving at a slow speed. The squeal noise is caused by the disc pad surface fluctuating. To eliminate this concern, the brake pads have been modified.
SA-016-24b	2024-09-04. Service bulletin. Some vehicles exhibit brake related concerns such as brake noise, brake judder or brake dragging. If you encounter a customer complaint for any one of these symptoms, refer to the following information to understand why symptoms may occur, and to better assist the customer in resolving their specific brake concern.
04-001-24a	2024-09-04. Service bulletin. Symptom 1: Some customers may complain about hearing a grinding noise and/or vibration occur when applying the brake. This is due to rust on the rear brake disc plate. The brake pad has insufficient disc-rust prevention performance, resulting in the disc plate rusting. To eliminate this concern, the pad material has been improved to prevent rust on the disc surface. Symptom 2: Some vehicles may exhibit a squeal noise from the rear brakes when braking lightly while driving at a slow speed. The squeal noise is caused by the disc pad surface fluctuating.
SA-016-24a	2024-07-05. Other. Some vehicles exhibit brake related concerns such as brake noise, brake judder or brake dragging. If you encounter a customer complaint for any one of these symptoms, refer to the following information to understand why symptoms may occur, and to better assist the customer in resolving their specific brake concern.
SA-007-24a	2024-05-04. Service bulletin. This information will give you the necessary knowledge to respond to customers concerns of Smart Brake Support (SBS) unintended braking. By educating the customer on the system operation, it should reduce their anxiety or distrust of the vehicle.
SA-021-24	2024-05-03. Service bulletin. Some customers may complain about intermittent audio no sound from the MAZDA CONNECT infotainment system and/or static noise from the speakers. The concern may be reproduced by tapping on the dash pad near the MAZDA CONNECT center display and the following DTC's may be stored. U0186:08 Communication error with audio amplifier U2145:08 Communication error with remote tuner (RT) U2145:02 Communication error with remote tuner (RT)