2026 Mazda Mazda3 TSBs

The changes are noted in Red text. SA-042/26 06/30/26 DESCRIPTION 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 Resources MyMazda App Error Codes Customer Opt-Out

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) 5. Non-certified USB cable (Apple Carplay/ Android Auto will not connect) 6. Over-sized wheels/tires (incorrect GPS location) 7. DTC C0023:14 8. Decorative trim and/or cover on the START/STOP ENGINE button

P0126:00 Dear Mazda Dealer Colleagues, Mazda Motor Corporation has decided to conduct a Dealer Re-Work on certain 2026MY CX-30 and Mazda3 vehicles. Concern Outline: On certain subject vehicles, the check engine light may illuminate with DTC P0126:00 (Thermostat stuck open) stored due to improper PCM control logic. Repair Outline: Reprogram the PCM with the Mazda Modular Diagnostic System (M-MDS), using Mazda Diagnostic and Repair Software (MDARS) by following TSB 01-006/26 repair instructions. ACTION ITEM - STOP DELIVERY: All affected vehicles in inventory can be sold but not delivered until repaired. There are approximately 17,942 new vehicles in dealer stock and/or in transit to dealers. All affected dealer inventory types with this DRW must be repaired prior to delivery. The number of affected units at your dealership can be seen in Inventory & Sales 2.0 in eMDCS and a VIN list (via an internal MNAO campaign reporting) will also be provided to your District Service Manager by 5pm (Pacific Time) on the date this dealer email is sent. Owner Notification: There is no Owner Notification with this or any Dealer Re-Work. PARTS INFORMATION: There are no parts required for this repair.

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

Zinc-plated whisker may form inside the EPS motor and trigger the DTC. However, since it is cleared when power is supplied during DTC detection, normal operation can be restored by turning the ignition OFF and then ON. Furthermore, there is no possibility of recurrence. This case may be resolved through a simple inspection or repair without the need for parts replacement, potentially avoiding unnecessary customer waiting time.

Infotainment Center Display does not provide the Authorization Code (OTP) during the MyMazda App Connected Vehicle enrollment. 2. Remote function(s) 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

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 Resources MyMazda App Error Codes Customer Opt-Out

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) 5. Non-certified USB cable (Apple Carplay/ Android Auto will not connect) 6. Over-sized wheels/tires (incorrect GPS location) 7. DTC C0023:14 8. Decorative trim and/or cover on the START/STOP ENGINE button Example 1: Some electrical devices connected to the DLC-2 connector by insurance or mobile phone companies may cause: Battery discharge. The device may disrupt the CAN system battery saver mode. IDS/MMDS will not communicate with the vehicle due to poor DLC-2 connection. The aftermarket device may cause DLC-2 female terminals to spread open.

The changes are noted below in Red. SA-029/25 10/16/25 and 06/02/25 DESCRIPTION This service information provides testing and charging procedures in order to promote proper battery maintenance, to deliver new vehicles with fully charged batteries, and to reduce unnecessary battery replacement cost. For new vehicles in stock at the dealer, inspect and maintain the batteries periodically according to the repair procedure. REPAIR PROCEDURE HIGH VOLTAGE BATTERY MAINTENANCE Verify the State-of-charge (SOC) in the instrument cluster. MX-30 EV: If the SOC is lower than 26%, charge it to 50% (either by normal charging or quick charging). CX-90/CX-70 PHEV: If the SOC is lower than 1%, charge it to 10% (either by normal charging, quick charging or engine running).

The changes are noted in Red text. MT-002/19 09/30/19 and 12/19/19 DESCRIPTION If an engine assembly is replaced after a catastrophic internal mechanical failure, clean the intake manifold internally before installing a replacement engine assembly. If the intake manifold is not cleaned properly, the replacement engine may fail prematurely. Metallic debris from the old engine (with catastrophic internal mechanical failure) may rest inside the intake manifold. When the new engine assembly is installed, debris in the intake manifold will be ingested into the new engine and cause internal damage. Clean the intake manifold internally to remove any debris from old engine before installing the new replacement engine assembly. If the intake manifold cannot be properly cleaned internally, replace it.

P0126:00 Dear Mazda Dealer Colleagues, Mazda Motor Corporation has decided to conduct a Dealer Re-Work on certain 2026MY CX-30 and Mazda3 vehicles. Concern Outline: On certain subject vehicles, the check engine light may illuminate with DTC P0126:00 (Thermostat stuck open) stored due to improper PCM control logic. Repair Outline: Reprogram the PCM with the Mazda Modular Diagnostic System (M-MDS), using Mazda Diagnostic and Repair Software (MDARS) by following TSB 01-006/26 repair instructions. ACTION ITEM - STOP DELIVERY: All affected vehicles in inventory can be sold but not delivered until repaired. There are approximately 17,942 new vehicles in dealer stock and/or in transit to dealers. All affected dealer inventory types with this DRW must be repaired prior to delivery. The number of affected units at your dealership can be seen in Inventory & Sales 2.0 in eMDCS and a VIN list (via an internal MNAO campaign reporting) will also be provided to your District Service Manager by 5pm (Pacific Time) on the date this dealer email is sent. Owner Notification: There is no Owner Notification with this or any Dealer Re-Work. PARTS INFORMATION: There are no parts required for this repair.

P0126:00 Dear Mazda Dealer Colleagues, Mazda Motor Corporation has decided to conduct a Dealer Re-Work on certain 2026MY CX-30 and Mazda3 vehicles. Concern Outline: On certain subject vehicles, the check engine light may illuminate with DTC P0126:00 (Thermostat stuck open) stored due to improper PCM control logic. Repair Outline: Reprogram the PCM with the Mazda Modular Diagnostic System (M-MDS), using Mazda Diagnostic and Repair Software (MDARS) by following TSB 01-006/26 repair instructions. ACTION ITEM - STOP DELIVERY: All affected vehicles in inventory can be sold but not delivered until repaired. There are approximately 17,942 new vehicles in dealer stock and/or in transit to dealers. All affected dealer inventory types with this DRW must be repaired prior to delivery. The number of affected units at your dealership can be seen in Inventory & Sales 2.0 in eMDCS and a VIN list (via an internal MNAO campaign reporting) will also be provided to your District Service Manager by 5pm (Pacific Time) on the date this dealer email is sent. Owner Notification: There is no Owner Notification with this or any Dealer Re-Work. PARTS INFORMATION: There are no parts required for this repair.

P0126:00 Dear Mazda Dealer Colleagues, Mazda Motor Corporation has decided to conduct a Dealer Re-Work on certain 2026MY CX-30 and Mazda3 vehicles. Concern Outline: On certain subject vehicles, the check engine light may illuminate with DTC P0126:00 (Thermostat stuck open) stored due to improper PCM control logic. Repair Outline: Reprogram the PCM with the Mazda Modular Diagnostic System (M-MDS), using Mazda Diagnostic and Repair Software (MDARS) by following TSB 01-006/26 repair instructions. ACTION ITEM - STOP DELIVERY: All affected vehicles in inventory can be sold but not delivered until repaired. There are approximately 17,942 new vehicles in dealer stock and/or in transit to dealers. All affected dealer inventory types with this DRW must be repaired prior to delivery. The number of affected units at your dealership can be seen in Inventory & Sales 2.0 in eMDCS and a VIN list (via an internal MNAO campaign reporting) will also be provided to your District Service Manager by 5pm (Pacific Time) on the date this dealer email is sent. Owner Notification: There is no Owner Notification with this or any Dealer Re-Work. PARTS INFORMATION: There are no parts required for this repair.

SA-035/24 05/31/24 DESCRIPTION There is a concern that some water pumps are being replaced that are not faulty, due to signs of a very small coolant leak from the bleed hole. This Service Alert is to inform you about the water pump sealing mechanism and the criteria if replacement is necessary or not. A mechanical seal (A) is used for the water pump. This mechanical seal can seal coolant (B) by sliding a mating ring (C) against a seal ring (D). When the sliding surface temperature of the mechanical seal is more than 248 F (120 C) while driving, a small amount of steam (E) is leaked and bleeds through the bleeding hole (F). After drying, the steam leaves a green coolant deposit near the water pump bleed hole (F). This is a normal condition and does not require water pump replacement. The water pump should only be replaced if there is an accumulation of crystallized coolant near the bleed hole. When you encounter a water pump with coolant seepage marks, decide to replace it or not based on the following criteria using sample photos. NOTE: During the initial period of use*, the sliding surfaces of the seals may not yet be fully settled, which can temporarily increase the amount of leakage. Continued use will allow the surfaces to settle, reducing the leakage. Replacing parts that are already settled with new ones will increase the leakage again until the new parts become conditioned. Therefore, replacement should be avoided in this initial period of use. *As a guideline, this applies to vehicles with less than 1,860 miles (3000 km) of mileage.

This is due to improper PCM logic control. To eliminate the concern, the PCM control software has been modified. REPAIR PROCEDURE 1. Verify the customer concern. 2. Reprogram the ECU with the Mazda Modular Diagnostic System (M-MDS), using Mazda Diagnostic and Repair Software (MDARS). Refer to MDARS ECU Reprogramming Procedure. NOTE: Be sure to submit Diagnostic Information (ODR) data as it is a required item and will be checked during warranty claim submission. Instructions can be found under M-MDS -> MDARS (Uploading Diagnostic Information (ODR) Data). 3. Clear any other DTCs. 4. Verify the repair by starting the engine (READY ON) and confirming there is no CHECK ENGINE light ON or abnormal warning lights present.

A. Auxiliary Key Trace Cut Method B. Auxiliary Key Code Cut Method 2019 and newer models require a 10-digit key code to accurately cut keys 5-digit codes CANNOT be provided for 2019 and newer vehicles (the traditional 5-digit code from the key tag or driver's door lock cylinder is not sufficient and will not be issued for key cutting on these models). Only Mazda-approved key cutting machines can process these 10-digit codes. Many older key machines do not support 10-digit codes and cannot be updated to do so. In these cases, dealers will need to purchase one of the newer Mazda-approved key cutting machines capable of handling this requirement. For a list of current Mazda-approved machines and purchasing options, refer to the Mazda Dealer Equipment Program or view the current Mazda approved key machines below.

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.

Infotainment Center Display does not provide the Authorization Code (OTP) during the MyMazda App Connected Vehicle enrollment. 2. Remote function(s) inoperative. Engine Start / Stop Door Lock / Unlock Lights ON / OFF Climate Control 3. MAZDA CONNECT connected vehicle reception strength icon shows "X" or "\". Page

experience a DTC P0126:00.

For this concern, inspect the vehicle for any trace of a fluid or oil leak and use the following examples as a guide to determine if it is severe enough to require a repair, or just to clean the area and monitor it at the next service. Examples of residue or seepage that may not be considered a leak and that may not require repair based on splash shield inspection.

ATF-A7 is an extremely low viscosity formulation with low friction to achieve best-in-class fuel economy and driving performance. For easy identification, ATF-A7 is colored Red and ATF-FZ is colored Blue. ATF-A7 includes UV-reactive dye (see "Fluorescence Example" below). There is NO interchangeability between ATF-A7 and ATF-FZ. For CX-30, Mazda3, and CX-5, some 2.5L and all 2.5T engines still use ATF-FZ. Verify the type of ATF according to what is in MGSS (TRANSMISSION/TRANSAXLE TECHNICAL DATA) or what is marked on the dipstick (see "ATF-A7 Identification" below).

ATF-A7 is an extremely low viscosity formulation with low friction to achieve best-in-class fuel economy and driving performance. For easy identification, ATF-A7 is colored Red and ATF-FZ is colored Blue. There is NO interchangeability between ATF-A7 and ATF-FZ. For CX-30, Mazda3, and CX-5, some 2.5L and all 2.5T engines still use ATF-FZ. Verify the type of ATF according to what is in MGSS (TRANSMISSION/TRANSAXLE TECHNICAL DATA) or what is marked on the dipstick (see below).

Infotainment Center Display does not provide the Authorization Code (OTP) during the MyMazda App Connected Vehicle enrollment. 2. Remote function(s) inoperative. Engine Start / Stop Door Lock / Unlock Lights ON / OFF Climate Control 3. MAZDA CONNECT connected vehicle reception strength icon shows "X" or "\".

Infotainment Center Display does not provide the Authorization Code (OTP) during the MyMazda App Connected Vehicle enrollment. 2. Remote function(s) inoperative. Engine Start / Stop Door Lock / Unlock Lights ON / OFF Climate Control 3. MAZDA CONNECT connected vehicle reception strength icon shows "X" or "\".

The changes are noted in Red text. SA-038/26 08/18/26 and 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

VIEW VEHICLE STATUS MONITOR FOR DETAILS" on the center display even after the recall has been completed. NOTE: Once the warranty claim for the recall campaign is approved by Mazda Japan, the recall notification will be automatically removed via Connected Services on the following day or later. This condition may occur if the Connected Services subscription was canceled while the recall notification was still active. ACTION TO BE TAKEN If you encounter the situation above, use MDARS to manually remove the center display recall notification. Note: MDARS can only remove the recall notification when MCVV shows no CV contract.

The changes are noted in Red. SA-009/25 08/22/25 and 02/18/25 DESCRIPTION Some customers may experience a Connected Vehicle failure. The MyMazda App may display an Error Code. This document provides Error Code description and recovery information to assist with repairs. Index System Outline MYMAZDA App Connected Vehicle (CV) Error Codes Vehicle Confirmation Instructions Troubleshooting Instructions Resources

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 -> Infotainment -> MAZDA CONNECT Updates If possible, complete the Microsoft Forms Questionnaire. Go to MGSS -> Infotainment -> MAZDA CONNECT Questionnaire.

below provide an overview of bug fixes, feature improvements, and updates included in the latest software release. The latest version of software contains all the updates of the previous versions. NOTE: If current version is not 7230C**-NA10_*****, this TSB is not applicable. Version 10034 for 7230C1A-NA10 or 7230C5B-NA10 enables termination of connected services at customer request Termination of Connected Services by customers at their initiative has been enabled. Accordingly, the following items have been updated. Add a "Data Communication Information" item under Settings > System Settings>Online Connectivity. Updated the text displayed on the confirmation screen for disabling Connected Services. REPAIR PROCEDURE 1. Verify the customer concern. 2. Update MAZDA CONNECT with software version 10034 / 10026 or later with a USB memory stick using the 7TH GEN MAZDA CONNECT Update Instructions.

If the customer's vehicle is among the trim levels referenced above it is equipped with a 6-speaker infotainment system and does not include rear door speakers even though there are speaker grills/covers in the rear door panels. MazdaUSA and published vehicle specifications provide the correct information indicating that these trims are equipped with a "6-speaker audio system". This is a normal condition of the "6-speaker audio system" and current Mazda CONNECT fader function. Rear speaker diagnosis is not necessary as they are not equipped.

Multi-information display OR display a system status notice with no DTC: C1001:92 - Forward sensing camera (FSC) poor field of view [Gen 6 vehicles] B14F0:92 - General temporary failure in forward sensing camera (FSC) [Gen 7 vehicles built on or before March 2, 2019] No DTC - Warning Message only [Gen 7 vehicles built after March 2, 2019] DTC C1001:92 or B14F0:92 set as a past record for low visibility of the Forward Sensing Camera (FSC). It does not mean there is an actual FSC defect. In some cases the customer may have a concern with the Lane Departure Warning System (LDWS) and/or High Beam Control system (HBC). In other cases this DTC might be found without a related customer concern.

inform SiriusXM of the existing Radio ID and the new/replacement SAT Radio ID as soon as possible to ensure the customer leaves the dealership with an active SAT radio.

Navigation Data Unavailable" or "Check Navigation SD Card" in the meter while driving.

The MyMazda App may display an Error Code. This document provides Error Code description and recovery information to assist with repairs.

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.

The changes are noted in Red. SA-063/24 09/06/24 DESCRIPTION The Blind Spot Monitoring (BSM) system can malfunction with the following symptoms if the rear side radar sensors are installed facing the wrong direction.

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 the top of the battery to identify a battery by the capacity (amps), dimensions, and battery terminal type. Vehicles manufactured in Japan come from the factory with a JIS rated battery. NOTE: Replacement batteries may use a CCA rating. If so, use the CCA rating listed on the battery. REPAIR PROCEDURE 1. Perform appropriate repair to vehicle. If needed, use the Battery Diagnostics of the DCA-8000 to test the charging and starting systems by following the on-screen instructions for entering the appropriate information. Refer to the Mazda DCA-8000 Instruction Manual for more information.

The changes are noted below in Red. SA-007/25 10/22/25, 06/02/25 and 02/03/25 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 the top of the battery to identify a battery by the capacity (amps), dimensions, and battery terminal type. Vehicles manufactured in Japan come from the factory with a JIS rated battery. NOTE: Replacement batteries may use a CCA rating. If so, use the CCA rating listed on the battery. 2. CCA (Cold Cranking Amps): CCA ratings are normally located on a sticker affixed to the top of the battery to indicate a batterys Cold Cranking Amps. CCA rated batteries are supplied with domestically produced vehicles. NOTE: If an incorrect CCA rating is entered into the Mazda DCA-8000, it will result in a false result and invalid Warranty Code from the tester. This will also result in unnecessary replacement of batteries. TEST PROCEDURE 1. Connect the charger clamps to the appropriate battery posts.

Have the Vehicle Inspected" in the instrument cluster. Additional symptoms that may occur: Connected Vehicle One Time Passcode (OTP) may fail. Connected Vehicle Remote functions may fail. The following DTC's may be stored: B1252:87-8B:TCU - COMMUNICATION ERROR WITH CONNECTIVITY MASTER UNIT (CMU) U0198:00-03:CMU - COMMUNICATION ERROR WITH EMERGENCY CALL UNIT/TELEMATICS COMMUNICATION UNIT REPAIR PROCEDURE 1. Verify the concern. 2. Check if any of the following DTCs are stored: B1252:87-8B:TCU - COMMUNICATION ERROR WITH CONNECTIVITY MASTER UNIT (CMU) U0198:00-03:CMU - COMMUNICATION ERROR WITH EMERGENCY CALL UNIT/TELEMATICS COMMUNICATION UNIT Are the following DTCs stored? YES: Proceed to next step. NO: This service information does not apply. Continue troubleshooting using MGSS. 3. Check for electrical devices in the vehicle such as a device connected to USB hub, Dash Cam, Insurance Device, FasTrak........ect. Are there any customer electrical devices in the vehicle? YES: Document customer device used, then go to the next step. NO: Go to the next step. 4. Clear the DTC's

The changes are noted in Red. SA-012/26 02/26/2026 DESCRIPTION Some customers may experience a message "TCU Malfunction. Have the Vehicle Inspected" in the instrument cluster. Additional symptoms that may occur: Connected Vehicle One Time Passcode (OTP) may fail. Connected Vehicle Remote functions may fail. The following DTC's may be stored: B1252:87-8B:TCU - COMMUNICATION ERROR WITH CONNECTIVITY MASTER UNIT (CMU) U0198:00-03:CMU - COMMUNICATION ERROR WITH EMERGENCY CALL UNIT/TELEMATICS COMMUNICATION UNIT REPAIR PROCEDURE 1. Verify the concern. 2. Check if any of the following DTCs are stored: B1252:87-8B:TCU - COMMUNICATION ERROR WITH CONNECTIVITY MASTER UNIT (CMU) U0198:00-03:CMU - COMMUNICATION ERROR WITH EMERGENCY CALL UNIT/TELEMATICS COMMUNICATION UNIT Are the following DTCs stored? YES: Proceed to next step. NO: This service information does not apply. Continue troubleshooting using MGSS. 3. Check for electrical devices in the vehicle such as a device connected to USB hub, Dash Cam, Insurance Device, FasTrak........ect. Are there any customer electrical devices in the vehicle? YES: Document customer device used, then go to the next step. NO: Go to the next step. 4. Check for a Navi SD Card. Is the vehicle equipped with a Navi SD Card? YES: Replace the Navi SD Card. NO: Go to next step. 5. Complete the Dealer Connected Vehicle Questionnaire. 6. Collect CMU log data. Go to Infotainment/TCU --> Collecting CMU Log Data --> CMU Log Data Retrieval Instructions 7. Collect TCU log data. Go to Infotainment/TCU --> TCU Log Data Retrieval Instructions --> CMU Log Data Retrieval Instructions 8. Contact Hotline for additional assistance. 9. Release the vehicle to the customer. NOTE: This concern is currently under investigation

It is most noticeable when the A/C is first turned ON. This odor is the result of mold growth in the A/C evaporator/cooling unit which is caused by condensation, dust, and pollen within the cooling unit. This condition is usually worse during high humidity conditions. Mazda Air Cooling Coil Coating is available to encapsulate the mold to reduce odors. If the product is properly applied, it can effectively reduce the musty/mildew odor for up to three years. NOTE: See parts information for Mazda Air Cooling Coil Coating and Kit part numbers.

The terminal test kit enables you: To check pin fit drag of all PCM terminals used in SKYACTIV vehicles and compare suspect terminal drag with a known good terminal. To measure the voltage/resistance avoiding any terminal damage.

deliver new vehicles with fully charged batteries, and to reduce unnecessary battery replacement cost. For new vehicles in stock at the dealer, inspect and maintain the batteries periodically according to the repair procedure.

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 the top of the battery to identify a battery by the capacity (amps), dimensions, and battery terminal type. Vehicles manufactured in Japan come from the factory with a JIS rated battery. NOTE: Replacement batteries may use a CCA rating. If so, use the CCA rating listed on the battery.

Have the Vehicle Inspected" in the instrument cluster. Additional symptoms that may occur: Connected Vehicle One Time Passcode (OTP) may fail. Connected Vehicle Remote functions may fail. The following DTC's may be stored: B1252:87-8B:TCU - COMMUNICATION ERROR WITH CONNECTIVITY MASTER UNIT (CMU) U0198:00-03:CMU - COMMUNICATION ERROR WITH EMERGENCY CALL UNIT/TELEMATICS COMMUNICATION UNIT REPAIR PROCEDURE 1. Verify the concern. 2. Check if any of the following DTCs are stored: B1252:87-8B:TCU - COMMUNICATION ERROR WITH CONNECTIVITY MASTER UNIT (CMU) U0198:00-03:CMU - COMMUNICATION ERROR WITH EMERGENCY CALL UNIT/TELEMATICS COMMUNICATION UNIT Are the following DTCs stored? YES: Proceed to next step. NO: This service information does not apply. Continue troubleshooting using MGSS.

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.

The changes are noted in Red. SA-012/26 04/17/26, 03/04/26 and 02/26/2026 DESCRIPTION Some customers may experience a message "TCU Malfunction. Have the Vehicle Inspected" in the instrument cluster. Additional symptoms that may occur: Connected Vehicle One Time Passcode (OTP) may fail. Connected Vehicle Remote functions may fail. The following DTC's may be stored: B1252:87-8B:TCU - COMMUNICATION ERROR WITH CONNECTIVITY MASTER UNIT (CMU) U0198:00-03:CMU - COMMUNICATION ERROR WITH EMERGENCY CALL UNIT/TELEMATICS COMMUNICATION UNIT REPAIR PROCEDURE 1. Verify the concern. 2. Check if any of the following DTCs are stored: B1252:87-8B:TCU - COMMUNICATION ERROR WITH CONNECTIVITY MASTER UNIT (CMU) U0198:00-03:CMU - COMMUNICATION ERROR WITH EMERGENCY CALL UNIT/TELEMATICS COMMUNICATION UNIT

The changes are noted in Red. SA-060/25 12/16/25 Some customers may experience a message "TCU Malfunction. Have the Vehicle Inspected" in the instrument cluster. Additional symptoms that may occur: Connected Vehicle One Time Passcode (OTP) may fail. Connected Vehicle Remote functions may fail. The following DTC's may be stored: B1252:87-8B:TCU - COMMUNICATION ERROR WITH CONNECTIVITY MASTER UNIT (CMU) U0198:00-03:CMU - COMMUNICATION ERROR WITH EMERGENCY CALL UNIT/TELEMATICS COMMUNICATION UNIT

The changes are noted in Red text. 09-043/25 11/26/2025 DESCRIPTION Some vehicles may experience a clicking noise when opening and/or closing the front door due to a broken front door checker plate. To reduce the clicking noise, the material of the plastic component in the door checker has been modified. REPAIR PROCEDURE 1. Verify the customer concern. 2. Replace the front door checker plate with the interim countermeasure part according to the instructions on MGSS FRONT DOOR CHECKER REMOVAL/INSTALLATION. NOTE: Repair only the affected side.

To obtain a replacement VIN plate (bulkhead-mounted and visible through the lower-left area of the windshield), contact DAG (Dealer Assistance Group) using VIN Plate Request Form available on One Mazda. To obtain a replacement vehicle certification label (located on the Bpillar or front door), contact your assigned DSM (District Service Manager) to place the order. If DSM contact information is not available, refer to the Dealer & Field Contact Directory.

The changes are noted in Red. SA-045/22 12/06/22 and 07/12/22 NOTE: All vehicles with protective films applied to the piano black door garnishes of the following models are applicable to this Service Alert. DESCRIPTION The purpose of this Service Alert is to remind dealers to keep the protective films on the piano black door garnishes attached until just before delivering the vehicle to the customer. The protective films are attached on new vehicles when shipped from the factory in order to avoid being scratched during transportation and while in dealer stock. NOTE: Remove the protective films after cleaning the vehicle. If any adhesive residue remains on the surface of the door garnish, attach the adhesive side of the protective film on the area again, and then peel it off to remove the residue. Refer to the image below for the location of the protective films (4 sheets of films in each side).

checker plate.

This may be caused by insufficient sealing performance of the trunk lid weatherstrip. Due to improper installation of weatherstrips, the lip of the weatherstrip may lean toward the inside of the trunk, resulting in insufficient sealing performance. To eliminate this concern, the length of the trunk lid weatherstrip has been extended 14 mm {0.5 in.}.

This may be caused by the sun's reflection. If a structure's windows create enough of a curve, the concave glass can focus the sun's rays onto a small area and acting like magnifiying glass direct the sunbeams into a hot pinpoint of light. This magnifcation of the sun's rays can cause damage to vehicle trim (see examples). Additional information and exemplar images regarding this phenomenon can be found by performing a google search.

This may be caused by insufficient sealing performance of the trunk lid weatherstrip. Due to improper installation of weatherstrips, the lip of the weatherstrip may lean toward the inside of the trunk, resulting in insufficient sealing performance.

The changes are noted in Red text. SA-047/25 10/07/25 DESCRIPTION When the Telematics Control Unit (TCU) replacement is necessary due to a failure, use MDARS to activate 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: DO NOT swap TCU with another vehicle as the TCU is VIN locked after activation. A TCU swap with another vehicle will disable Connected Services on both vehicles. If TCU activation 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. If the Telematics Control Unit (TCU) replacement is necessary, check "Vehicle Communication Line Status Reference" status detail first. The TCU can only be replaced under the following "Status Detail" conditions: Open Completed (OK) Closed Completed (OK) If the TCU is replaced under the following "Status Detail" conditions, the customer may not be able to enroll into the replacement TCU. Processing (NG) Request Failed (NG) Open Failed (NG) Flag Setting Failed TCU Activation 1. Install the new TCU.

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 (Owners Manual, Workshop Manual, Technical Service Bulletin, etc.).

new upholstery is installed under Warranty repair. NOTE: This repair is not a permanent fix, it is meant to make new seats look their best when the vehicle is first presented to the customer. Wrinkles may not be completely removed after the repair is completed. Leather is a natural material and may develop some wrinkles due to aging and wear during normal usage.

conditions of use, the antistatic components may crystallize slightly, giving an appearance of white stains on the surface.

The changes are noted in Red. SA-011/25 10/16/25 and 02/27/25 DESCRIPTION Some customers will report that their fuel door (AKA, fuel filler door, fuel lid, and fuel-filler lid) was stuck closed and would not open to refuel the vehicle. Follow the repair steps below unless the conditions outlined in TSB 09-007/25 - FUEL-FILLER LID PANEL IS DEFORMED for 2019-2025 Mazda3 and 2020-2025 CX-30 are present. REPAIR PROCEDURE 1. Check for pry marks around the door opening. Are there any pry marks? YES: This is due to outside influence and is not covered by Mazda warranty. NO: Continue to the next step. 2. Check the fuel door lock operation. a. Lock the doors and verify if the fuel door lock is locking. NOTE: The default setting is a 90-second delay after the doors lock, but the customer can set that to 0, 30, 60, 90, or 120 seconds. b. Unlock the doors and verify if the fuel door lock is unlocking. NOTE: There is no delay to this function, but the fuel door must be locked to confirm it is unlocking. See the lock note above. Is the fuel door lock operation working correctly? YES: The fuel door repair IS NOT covered by Mazda warranty. The fuel door lock is OK and the door was damaged because the vehicle was not unlocked. NO: The fuel door repair IS covered by Mazda warranty. The fuel door lock is NOT OK and damage to the door was done in order to access the lock. NOTE: If the door was already broken when it arrived at the dealership, Mazda will pay for the fuel door repair under warranty if the vehicle does NOT have an emergency release. Mazda will NOT pay for the fuel door under warranty if it has an emergency release.

(default setting is 90 seconds), the fuel-filler lid does not lock, but can be opened when pressed. NOTE: The fuel-filler lid does not lock immediately after the doors are locked, but after the time set in the Fuel Door Lock Delay (0, 30, 60, 90, and 120 seconds). Although the root cause has not been identified, the vehicle should be repaired by adjusting the fuel-filler lid opener cable position when there is a customer complaint.

and would not open to refuel the vehicle. Follow the repair steps below unless the conditions outlined in TSB 09-007/25 - FUEL-FILLER LID PANEL IS DEFORMED for 2019-2025 Mazda3 and 2020-2025 CX-30 are present.

Have the Vehicle Inspected" in the instrument cluster. The following DTC's may be stored: B1252:87-8B:TCU - COMMUNICATION ERROR WITH CONNECTIVITY MASTER UNIT (CMU) U0198:00-03:CMU - COMMUNICATION ERROR WITH EMERGENCY CALL UNIT/TELEMATICS COMMUNICATION UNIT

This is considered normal and NO repair should be performed. During production, differential ring and pinion gears receive a manganese phosphate coating (commonly referred to as black oxide). This coating forms a porous, oil-retentive surface that improves boundary lubrication and reduces adhesive wear during initial contact cycles. Designed as a sacrificial layer, it is gradually removed under load throughout the break-in process. As a result, after the first few hundred miles, or at the initial gear oil service interval, the lubricant may appear darkened by the worn-off coating. It will contain trace ferrous particles from the normal run-in of the gear teeth and bearing surfaces. This condition is expected and does not, by itself, indicate an issue with the differential or PTO gears.

essential to first classify the issue into one of three primary categories: Noise, Vibration, or Harshness. Many customer complaints may involve overlapping symptoms, such as both noise and vibration, so identifying the dominant characteristic is critical. Once the primary symptom is determined, follow the appropriate diagnostic path. For example, if a concern includes both noise and vibration but is related to vehicle speed, the vibration diagnostic path should be followed. When considering component replacement during the diagnostic process, it is best practice to start with the lowest cost or most accessible part unless diagnostic evidence clearly identifies a more expensive or complex component as the root cause. This approach helps minimize repair costs and avoids unnecessary part replacements. For example, a growling or bearing whine noise may be mistakenly attributed to internal components in the differential, transfer unit, or transmission, when the actual source is a wheel bearing. Misdiagnosis like this can lead to unnecessary repairs, added time and cost. To help prevent this, always follow the guidelines in the repair procedure.

transmissions where the source of the noise was a wheel bearing. This misdiagnosis can lead to multiple repair attempts, warranty debits, and additional inconvenience and/or cost to the customer. To reduce the chance of this occurring, please follow the steps outlined in the repair procedure.

DESCRIPTION This Service Information is issued in accordance with New York State General Business Law 399CCCCC (Connected Vehicle Service; Domestic Violence Victims). This regulation is intended to protect victims of domestic violence by allowing them to request the termination of third-party access (including access by an alleged abuser) to connected vehicle services, such as vehicle location tracking and remote control functions. To support this requirement, this Service Information enables confirmation of whether a vehicle is subject to connected vehicle services by referring to the SUBJECT VIN & PRODUCTION DATE RANGE, and provides guidance on the procedure to terminate such services when a customer requests the removal of third-party access for an applicable vehicle. Effective July 1, 2026, if a customer requests action under this regulation, a CMU/CDC software update must be performed to enable appropriate control of connected vehicle service access. If no request is made by the customer, the CMU/CDC software update is not required. REPAIR PROCEDURE 1. Confirm that the customer has requested deactivation of connected services in accordance with New York State General Business Law related action. 2. Perform the CMU/CDC software update according to the procedures outlined in the appropriate TSB shown in the table below:

Use the information in this service alert to initialize the new TCU until the procedure on MGSS is updated.

Sidewall waviness/indentations/undulations are common on radial tires and are more noticeable on tires with taller sidewalls. The higher the tire pressure, the more noticeable the effect will be. Be sure to set the tire pressures at the recommended tire pressure on the vehicle tire label. Sidewall indentations are a cosmetic condition that does not affect the performance of the tires.

be wet.

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.