Some customers may experience a message "TCU Malfunction
Mazda technical service bulletin SA-012-26b for 2024-2026 Mazda MAZDA3, 2024-2026 Mazda CX-90 and 2024-2026 Mazda CX-30 and others.
- Bulletin number
- SA-012-26b
- Component
- 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
Owners of these vehicles have filed 129 complaints in the electrical category.
Vehicles covered
- Mazda MAZDA3 2024-2026 202420252026
- Mazda CX-90 2024-2026 202420252026
- Mazda CX-30 2024-2026 202420252026
- Mazda CX-50 2025-2026 20252026
- Mazda CX-90 Plug-In Hybrid 2024-2026 202420252026
- Mazda CX-70 2025-2026 20252026
- Mazda CX-50 Hybrid 2025-2026 20252026
- Mazda CX-70 Plug-In Hybrid 2025-2026 20252026
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