{"vehicle":{"id":"2026_mazda_mazda3","year":2026,"make":"Mazda","model":"Mazda3"},"code":"B1252","generic":false,"description":null,"bulletins":{"as_of":"2026-10-19","count":6,"bulletins":[{"nhtsa_id":11037632,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2026-10-01","date":"2026-09-18","document_id":"SA-012-26d","mfr_campaign":null,"component":"ELECTRICAL SYSTEM","summary":"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.","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2026/MC-11037632-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2026/MC-11037632-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/11037632"},{"nhtsa_id":11037017,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2026-09-04","date":"2026-08-07","document_id":"SA-012-26c","mfr_campaign":null,"component":"UNKNOWN OR OTHER; ELECTRICAL SYSTEM","summary":"This Service Alert supersedes the previously issued SA(s) listed below. 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","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2026/MC-11037017-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2026/MC-11037017-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/11037017"},{"nhtsa_id":11032015,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2026-05-04","date":"2026-04-18","document_id":"SA-012-26b","mfr_campaign":null,"component":"UNKNOWN OR OTHER; ELECTRICAL SYSTEM","summary":"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. Clear the DTC's","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2026/MC-11032015-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2026/MC-11032015-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/11032015"},{"nhtsa_id":11030631,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2026-04-02","date":"2026-03-04","document_id":"SA-012-26a","mfr_campaign":null,"component":"UNKNOWN OR OTHER; ELECTRICAL SYSTEM","summary":"This Service Alert supersedes the previously issued SA(s) listed below. 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","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2026/MC-11030631-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2026/MC-11030631-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/11030631"},{"nhtsa_id":11029531,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2026-03-04","date":"2026-02-27","document_id":"SA-012-26","mfr_campaign":null,"component":"UNKNOWN OR OTHER; ELECTRICAL SYSTEM","summary":"This Service Alert supersedes the previously issued SA(s) listed below. 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","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2026/MC-11029531-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2026/MC-11029531-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/11029531"},{"nhtsa_id":11026913,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2026-01-03","date":"2025-12-17","document_id":"SA-060-25","mfr_campaign":null,"component":"ELECTRICAL SYSTEM; UNKNOWN OR OTHER","summary":"Some customers may experience a message \"TCU Malfunction. 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","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2025/MC-11026913-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2025/MC-11026913-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/11026913"}],"url":"https://open.wenmarpro.com/makes/mazda/mazda3/2026/bulletins?code=B1252"},"related":{"components":[],"bulletins":[],"recalls":{"may_apply":true,"recalls":[],"lookup":{"nhtsa":"https://www.nhtsa.gov/recalls","tc":"https://wwwapps.tc.gc.ca/Saf-Sec-Sur/7/VRDB-BDRV/search-recherche/menu.aspx?lang=eng","maker":null}}},"url":"https://open.wenmarpro.com/makes/mazda/mazda3/2026/codes/B1252","note":"The bulletins listed name this code in NHTSA's summary, or are about the same components. A bulletin or a recall listed here may apply to the model year. None of it is a diagnosis.","attribution":["Contains information licensed under the Open Government Licence – Canada."]}