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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
SA-059-20b2020-10-05. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM:12V/24V/48V BATTERY. During BCM replacement, MDARS may display a Configuration Error warning message. This may be caused by any of the following:• Poor internet connection • MDARS failure• Low Battery. Perform the BCM Recovery Procedure below to manually configure the BCM.
SA-066-202020-10-05. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE; EQUIPMENT; ELECTRICAL SYSTEM:12V/24V/48V BATTERY. When performing vehicle services such as control unit software update, control unit registration/activation, CMU log data retrieval, etc., always do the following: • Use the GR8 battery charger SST to maintain battery voltage. See SA-063/20. • Use M-MDS hardware that is in good working condition. CAUTION: If the GR8 is not used or if the M-MDS hardware is not in good working condition, a control unit failure may occur.
05-002-20-3704a2020-10-02. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE; POWER TRAIN. Some customers may complain about a surging at low speeds and during acceleration. This surging is in the longitudinal direction, felt about 2 cycles per second, and occurs in the locked up 1st gear. This may be caused by the torque fluctuation and the torsional resonance in the torque converter. To correct this concern, the PCM software has been modified to reduce the torque fluctuation.
SA-063-202020-09-03. Service bulletin. ELECTRICAL SYSTEM. When performing vehicle services such as control unit software update, control unit registration/activation, CMU log data retrieval, etc., always use the GR8 battery charger SST to maintain battery voltage.
SA-060-202020-09-01. Service bulletin. ELECTRICAL SYSTEM. When replacing the Body Control Module (BCM) in a 2019 Mazda3, it needs to be configured and the instructions in the Workshop manual on MGSS are incorrect. Use the instructions in the Repair Procedure below to configure the new BCM.
SA-014-20a2020-09-01. Service bulletin. ELECTRICAL SYSTEM. On some vehicles, the Commander switch might be inoperative. This could be caused by fuse F13 (15A) being removed instead of F15 (15A) at the factory in the lower panel compartment on the left side of the steering wheel.
16-003-20-37312020-09-01. Service bulletin. POWER TRAIN:CLUTCH ASSEMBLY:PEDAL/HAND LEVER(MOTORCYCLE); ELECTRICAL SYSTEM:SOFTWARE; ENGINE AND ENGINE COOLING. Some customers may not be comfortable with being notified of an engine stall due to an error when operating the clutch pedal. When the engine stalls, the charging system warning light is illuminated and a vehicle malfunction notification is received through the MyMazda APP on the mobile device. This is caused by improper control software of the PCM. To eliminate this concern, the PCM software has been modified to avoid the unnecessary malfunction notification.
SA-054-20b2020-08-05. Service bulletin. ELECTRICAL SYSTEM; ENGINE. Some customers may experience an engine no start due to low battery voltage on 2019-2020 Mazda3 and 2020 CX-30. Inform the customer that Mazda is actively investigating this issue and apologizes for any inconvenience. Mazda would like to request both dealer and customer support to expedite a repair. Customers having this concern should be instructed to contact Mazda Roadside Assistance and have their vehicle inspected by a local dealer.
SA-029-20f2020-08-05. Service bulletin. ELECTRICAL SYSTEM; ENGINE. Some customers may experience a "IN-VEHICLE NETWORK MALFUNCTION" warning message in the instrument cluster with one or more of the following DTC's stored:
SA-027-20c2020-08-05. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE. Customers having MAZDA CONNECT concerns should have their vehicle repaired using the following repair procedure.
MT-001-202020-08-04. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. 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 Workshop Manual diagnosis. Aftermarket devices may be the cause of the electrical concern. Ask the customer if any aftermarket devices have been installed. Below are a couple of examples of unusual electrical concerns caused by aftermarket devices.
16-002-20-37222020-08-04. Service bulletin. ELECTRICAL SYSTEM; LATCHES/LOCKS/LINKAGES:DOORS:LATCH; EQUIPMENT; ENGINE. When the vehicle is in sleep mode, some customers may experience a failed remote control attempt using the MyMazda APP, however, the second attempt works fine and no DTCs are stored. Remote control functions: - Remote Engine Start/Remote Engine Stop - Remote Door Lock/Remote Door Unlock - Remote Hazard Light. This concern may be caused by improper telematics communication unit control software. To eliminate this concern, the telematics communication unit software has been modified
07-003-20-37122020-08-04. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM:SOFTWARE. Some customers may hear a repeating click sound when using the HVAC system. The click sound may be caused by the air mix doors moving back and forth. This concern has been eliminated by a dash-electrical supply unit control software modification.
01-009-20-37102020-08-04. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING; EQUIPMENT. Some customers may complain about a very low frequency noise and/or vibration felt at the steering wheel, the floor and/or the seats when driving at 1500-1650 rpm in any gear position. This may be caused by normal vehicle behavior while the cylinder deactivation is active (two cylinders drive). The state of the cylinder deactivation can be monitored in the center display to help verify if this is the issue. WARNING: DO NOT keep your eyes focused solely on the display while test driving. For your safety, keep your eyes on the road ahead. To correct this concern, the radiator mount brackets and the control software of the PCM have been modified to reduce the resonance of the radiator. NOTE: The combination of the modified radiator mount brackets and older PCM calibration may result in worse vibration.
01-004-20-3684b2020-08-04. Service bulletin. ENGINE AND ENGINE COOLING; ELECTRICAL SYSTEM; POWER TRAIN:AUTOMATIC TRANSMISSION. Some customers may experience the master warning light turning on and a lack of power with DTC P2BF6:00 (Exhaust shutter valve position sensor circuit low input (1DC)) stored in memory. This is caused by improper logic written in the PCM for the exhaust shutter valve position sensor.
SA-029-20e2020-07-03. Service bulletin. ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL; EQUIPMENT:ELECTRICAL; ELECTRICAL SYSTEM. Some customers may experience a "IN-VEHICLE NETWORK MALFUNCTION" warning message in the instrument cluster with one or more of the following DTC's stored:• B119F:01 TCU - Tel antenna No. 1 malfunction • B119F:13 (TCU - TEL antenna No.1 circuit malfunction) • B119F:2B (CMU - GPS antenna signal circuit malfunction) • B1252:87 TCU - Communication error with connectivity master unit (CMU) • U0156:00 VCM - communication error with connectivity master unit (CMU) • U0156:00 BCM - Communication error with connectivity master unit (CMU) • U0198:00 BCM - Communication error with emergency call unit • U212D:00 BCM - Communication error with light control module (RH) • U3000:00 TCU - Telematics communication unit internal malfunction • Low Voltage Battery DTCs
SA-029-20d2020-07-03. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE; EQUIPMENT:ELECTRICAL; ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL. Some customers may experience a "IN-VEHICLE NETWORK MALFUNCTION" warning message in the instrument cluster with one or more of the following DTC's stored:• B119F:01 TCU - Tel antenna No. 1 malfunction • B119F:13 (TCU - TEL antenna No.1 circuit malfunction) • B119F:2B (CMU - GPS antenna signal circuit malfunction) • B1252:87 TCU - Communication error with connectivity master unit (CMU) • U0156:00 VCM - communication error with connectivity master unit (CMU) • U0156:00 BCM - Communication error with connectivity master unit (CMU) • U0198:00 BCM - Communication error with emergency call unit • U212D:00 BCM - Communication error with light control module (RH) • U3000:00 TCU - Telematics communication unit internal malfunction • Low Voltage Battery DTCs
SA-0290-20c2020-07-03. Service bulletin. EQUIPMENT:ELECTRICAL; ELECTRICAL SYSTEM:SOFTWARE. Some customers may experience a "IN-VEHICLE NETWORK MALFUNCTION" warning message in the instrument cluster with one or more of the following DTC's stored: • B119F:01 TCU - Tel antenna No. 1 malfunction • B1252:87 TCU - Communication error with connectivity master unit (CMU) • U0156:00 VCM - communication error with connectivity master unit (CMU) • U0156:00 BCM - Communication error with connectivity master unit (CMU) • U0198:00 BCM - Communication error with emergency call unit • U212D:00 BCM - Communication error with light control module (RH) • U3000:00 TCU - Telematics communication unit internal malfunction • Low Voltage Battery DTCs
SA-027-20b2020-07-03. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE; EQUIPMENT:ELECTRICAL. MAZDA CONNECT Software Version 11002 NOTE: “2019 Mazda3 owners may notice an icon in their infotainment’s display that indicates Mazda Connected Services. This new feature is a global technology and designed with the latest version of Mazda ConnectTM. At this time, the service is not active for 2019 Mazda3 vehicles in the U.S. Any updates to the service will be announced at the appropriate time.”Customers having MAZDA CONNECT concerns should have their vehicle repaired using the following repair procedure.
09-021-20-37142020-07-02. Service bulletin. ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL; EQUIPMENT:ELECTRICAL:NAVIGATIONAL SYSTEM(GLOBAL POSITIONING SYSTEM). Some customers may experience the master warning light and/or the "In-Vehicle Network Malfunction" warning message in the instrument cluster on with DTC B119F:01, B119F:13 and/or B119F:2B stored when the vehicle position cannot be displayed correctly. (TCU - Tel antenna No. 1 malfunction) (TCU - TEL antenna No.1 circuit malfunction) (CMU - GPS antenna signal circuit malfunction). This concern may be caused by incoming noise disturbing the reception of GPS signals, resulting in the wrong vehicle location and the DTC stored. To eliminate this concern, the GPS antenna has been modified.
05-002-20-37042020-07-02. Service bulletin. ENGINE; POWER TRAIN; ELECTRICAL SYSTEM:SOFTWARE. Some customers may complain about a surging at low speeds and during acceleration. This surging is in the longitudinal direction, felt about 2 cycles per second, and occurs in the locked up 1st gear. This may be caused by the torque fluctuation and the torsional resonance in the torque converter. To correct this concern, the PCM software has been modified to reduce the torque fluctuation.
01-004-20-3684a2020-07-02. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM); ENGINE AND ENGINE COOLING; ELECTRICAL SYSTEM:SOFTWARE. Some customers may experience the master warning light turning on and a lack of power with DTC P2BF6:00 (Exhaust shutter valve position sensor circuit low input (1DC)) stored in memory. The PCM software has been modified to avoid the unnecessary warning light illumination and power restriction with no modification to the cylinder deactivation function and the error detection logic has been changed not to detect false error under low voltage during cranking.
SA-007-20g2020-06-02. Service bulletin. ELECTRICAL SYSTEM. MAZDA CONNECTED SERVICES - FREQUENTLY ASKED QUESTIONS (FAQ). General Questions, Setup and Getting Started, Registration / Enrollment, WI-FI General Information, WI-FI How-To, WI-FI Trial Period, Interacting With The App, Service Issues, Troubleshooting, Dealer Processes, Educational Videos, Resources
SA-007-20f2020-06-02. Service bulletin. ELECTRICAL SYSTEM. MAZDA CONNECTED SERVICES - FREQUENTLY ASKED QUESTIONS (FAQ). General Questions, Setup and Getting Started, Registration / Enrollment, WI-FI General Information, WI-FI How-To, WI-FI Trial Period, Interacting With The App, Service Issues, Troubleshooting, Dealer Processes, Educational Videos, Resources
SA-010-20b2020-06-02. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. When the Telematics Control Unit (TCU) replacement is necessary due to a failure, use MDARS to initialize the new TCU after replacement. Use the information in this service alert to initialize the new TCU until the procedure on MGSS is updated. CAUTION: If TCU initialization is not performed, connected vehicle functions will not operate. This will have a negative impact on the customer because they will need to return to the dealer for repairs.

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