# U1A4B on the 2021 Mazda Mazda2

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.

This code is specific to a manufacturer and is not described here.

## Bulletins for this model year that name U1A4B

- [10225783](https://open.wenmarpro.com/bulletins/10225783), 2022-11-04: If the right\-side Blind Spot Monitoring \(BSM\) control module is replaced for any reason, it is also necessary to replace the left\-side BSM control module in order to complete the radar aiming procedure. If the right\-side BSM control module is replaced alone, "Automatic Configuration" and "BSM Radar Aiming" cannot be completed due to a programming error in the module. Other possible symptoms that may be found if the right\-side BSM module is replaced alone: \* BSM aiming fails \* "BSM OFF" indicator ON \* Center Display warning message \* BSM failsafe \(No operation\) \* DTC U3000:54 stored in memory \* DTC U1A4B:54 stored in memory \(CX\-3, MX\-5 only\)