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U1121 on the 2021 Cadillac Escalade ESV

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. Its meaning is in the manufacturer's service information.

Bulletins for this model year that name U1121
PIT5774G2024-04-15. Service bulletin. This Preliminary information communicates an issue with: Overhead Console Inoperative / Service Safety Restraints Message / Sunroof Inoperative / DTC's B1A7A and U1121. Dealers are to cycle the power to the overhead console to correct the issue. Engineering has released updated roof consoles to correct this concern. Dealers are to replace the roof console.
PIT5949C2023-05-15. Service bulletin. This Preliminary information communicates an issue during start up that the following symptoms occur: - Service Safety Restraints System Message - Sunroof Inoperative - Sunshade Lights Inoperative - Dome Lights Inoperative - Power Liftgate Inoperative when using switch in overhead console - DTCs U1121 set in the BCM and B1A7A set in the Restraints Module Dealers are to replace the overhead roof console with a new console that has revised software.
PIT5949B2023-05-15. Service bulletin. This Preliminary information communicates an issue during start up that the following symptoms occur: - Service Safety Restraints System Message - Sunroof Inoperative - Sunshade Lights Inoperative - Dome Lights Inoperative - Power Liftgate Inoperative when using switch in overhead console - DTCs U1121 set in the BCM and B1A7A set in the Restraints Module Engineering is currently working on a fix and in the meantime a customer can cycle the dome light switch on/off to correct the condition during that ignition cycle.
PIT5949A2023-02-13. Service bulletin. This Preliminary information communicates an issue during start up that the following symptoms occur: - Service Safety Restraints System Message - Sunroof Inoperative - Sunshade Lights Inoperative - Dome Lights Inoperative - Power Liftgate Inoperative when using switch in overhead console - DTCs U1121 set in the BCM and B1A7A set in the Restraints Module Engineering is currently working on a fix and in the meantime a customer can cycle the dome light switch on/off to correct the condition during that ignition cycle.
PIT59492022-10-17. Service bulletin. This Preliminary information communicates an issue during start up that the following symptoms occur: - Service Safety Restraints System Message - Sunroof Inoperative - Sunshade Lights Inoperative - Dome Lights Inoperative - Power Liftgate Inoperative when using switch in overhead console - DTCs U1121 set in the BCM and B1A7A set in the Restraints Module Engineering is currently working on a fix and in the meantime a customer can cycle the dome light switch on/off to correct the condition during that ignition cycle.

5 on file from NHTSA, as of 2026-10-19. See them in the bulletin list. A bulletin lists model years: read the document for which vehicles it concerns.