{"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,"replaces":null,"component":"UNKNOWN OR OTHER; ELECTRICAL SYSTEM","mfr_system":"Telematics Communication","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","components":[{"id":"electrical","name":"Electrical system","parent":null}],"codes":["B1252","U0198"],"topics":[],"vehicles":[{"make":"MAZDA","model":"CX-30","year_from":2024,"year_to":2026,"match":"exact","vehicle_ids":["2024_mazda_cx-30","2025_mazda_cx-30","2026_mazda_cx-30"]},{"make":"MAZDA","model":"CX-50","year_from":2025,"year_to":2026,"match":"exact","vehicle_ids":["2025_mazda_cx-50","2026_mazda_cx-50"]},{"make":"MAZDA","model":"CX-50 HYBRID","year_from":2025,"year_to":2026,"match":"base","vehicle_ids":["2025_mazda_cx-50","2026_mazda_cx-50"]},{"make":"MAZDA","model":"CX-70","year_from":2025,"year_to":2026,"match":"exact","vehicle_ids":["2025_mazda_cx-70","2026_mazda_cx-70"]},{"make":"MAZDA","model":"CX-70 PLUG-IN HYBRID","year_from":2025,"year_to":2026,"match":"base","vehicle_ids":["2025_mazda_cx-70","2026_mazda_cx-70"]},{"make":"MAZDA","model":"CX-90","year_from":2024,"year_to":2026,"match":"exact","vehicle_ids":["2024_mazda_cx-90","2025_mazda_cx-90","2026_mazda_cx-90"]},{"make":"MAZDA","model":"CX-90 PLUG-IN HYBRID","year_from":2024,"year_to":2026,"match":"base","vehicle_ids":["2024_mazda_cx-90","2025_mazda_cx-90","2026_mazda_cx-90"]},{"make":"MAZDA","model":"MAZDA3","year_from":2024,"year_to":2026,"match":"exact","vehicle_ids":["2024_mazda_mazda3","2025_mazda_mazda3","2026_mazda_mazda3"]}],"as_of":"2026-10-19","note":"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.","attribution":[]}