C1B56 on the 2020 Infiniti QX50
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.
| ITB20-025C | 2024-07-19. Service bulletin. DTC B2724-23 AND/OR C1B56-04 STORED, AND/OR RAB ERROR MESSAGE OR WARNING This bulletin has been amended. See AMENDMENT HISTORY on the last page. Please discard previous versions of this bulletin. |
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| ITB20-025B | 2021-08-06. Service bulletin. DTC B2724-23 AND/OR C1B56-04 STORED, AND/OR RAB ERROR MESSAGE OR WARNING This bulletin has been amended. See AMENDMENT HISTORY on the last page. Please discard previous versions of this bulletin. |
| ITB20-025a | 2021-02-06. Service bulletin. DTC B2724-23 AND/OR C1B56-04 STORED, AND/OR RAB ERROR MESSAGE OR WARNING This bulletin has been amended. See AMENDMENT HISTORY on the last page. Please discard previous versions of this bulletin. |
| ITB20-025 | 2020-12-08. Service bulletin. DTC B2724-23 AND/OR C1B56-04 STORED, AND/OR RAB ERROR MESSAGE OR WARNING IF YOU CONFIRM One or both of the following DTCs are stored: • B2724-23 (SONAR CONTROL UNIT - SONAR ECU INTERNAL FAILURE [UNDER VOLTAGE]) • C1B56-04 (SONAR CIRCUIT - SYSTEM INTERNAL MALFUNCTION) NOTE: A RAB warning may appear in the vehicle information display. ACTION Reprogram the Sonar Control Unit, if applicable. |
4 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.