Cadillac CT4 Service Bulletins (2023)

554 manufacturer communications on file.

• October 7, 2026•Document ID: 11038460

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT6110L

  Date Added:

  October 14, 2026

  Manufacturer:

  CADILLAC

  Summary

  This Preliminary information communicates an issue with the SES MIL and DTC P062B and engineering is currently investigating.

  Associated Products (84)

  2027 Buick Encore GX2027 Chevrolet Trailblazer2026 Buick Encore GX2026 Buick Envision2026 Cadillac CT42026 Cadillac CT52026 Cadillac Escalade2026 Cadillac Escalade ESV2026 Cadillac XT52026 Chevrolet Blazer2026 Chevrolet Colorado2026 Chevrolet Express2026 Chevrolet Silverado2026 Chevrolet Suburban2026 Chevrolet Tahoe2026 Chevrolet Trailblazer2026 GMC Canyon2026 GMC Savana2026 GMC Sierra2026 GMC Yukon+ 64 more
  Associated Documents

  • DownloadMC-11038460-0001.pdf↗
• September 28, 2026•Document ID: 11038136

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT6457C

  Date Added:

  October 5, 2026

  Manufacturer:

  CHEVROLET

  Summary

  This preliminary information is for technicians that may see DTCs that are history and should not perform any part replacements. They should follow the notes mentioned prior to anything being replaced.

  Associated Products (173)

  2027 Buick Enclave2027 Buick Encore GX2027 Cadillac Escalade IQ2027 Cadillac Escalade IQL2027 Cadillac Lyriq2027 Cadillac Optiq2027 Cadillac Vistiq2027 Chevrolet Blazer2027 Chevrolet Bolt EV2027 Chevrolet Corvette2027 Chevrolet Equinox2027 Chevrolet Suburban2027 Chevrolet Tahoe2027 Chevrolet Trailblazer2027 Chevrolet Traverse2027 GMC Acadia2027 GMC Sierra2027 GMC Terrain2027 GMC Yukon2027 GMC Yukon XL+ 153 more
  Associated Documents

  • DownloadMC-11038136-0001.pdf↗
• September 28, 2026•Document ID: 11038132

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIC6540K

  Date Added:

  October 5, 2026

  Manufacturer:

  CHEVROLET

  Summary

  This Preliminary information communicates to dealers a procedure to reset the radio.

  Associated Products (173)

  2027 Buick Enclave2027 Buick Encore GX2027 Cadillac Escalade IQ2027 Cadillac Escalade IQL2027 Cadillac Lyriq2027 Cadillac Optiq2027 Cadillac Vistiq2027 Chevrolet Blazer2027 Chevrolet Bolt EV2027 Chevrolet Corvette2027 Chevrolet Equinox2027 Chevrolet Suburban2027 Chevrolet Tahoe2027 Chevrolet Trailblazer2027 Chevrolet Traverse2027 GMC Acadia2027 GMC Sierra2027 GMC Terrain2027 GMC Yukon2027 GMC Yukon XL+ 153 more
  Associated Documents

  • DownloadMC-11038132-0001.pdf↗
• September 26, 2026•Document ID: 11037555

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT5698F

  Date Added:

  September 30, 2026

  Manufacturer:

  CADILLAC

  Summary

  This PI provides Diagnostics tips on how the LIN bus works and how to diagnosis it.

  Associated Products (619)

  2027 Buick Enclave2027 Buick Encore GX2027 Cadillac Escalade IQ2027 Cadillac Escalade IQL2027 Cadillac Lyriq2027 Cadillac Optiq2027 Cadillac Vistiq2027 Chevrolet Blazer2027 Chevrolet Bolt EV2027 Chevrolet Corvette2027 Chevrolet Equinox2027 Chevrolet Suburban2027 Chevrolet Tahoe2027 Chevrolet Trailblazer2027 Chevrolet Traverse2027 GMC Acadia2027 GMC Sierra2027 GMC Terrain2027 GMC Yukon2027 GMC Yukon XL+ 599 more
  Associated Documents

  • DownloadMC-11037555-0001.pdf↗
• September 21, 2026•Document ID: 11037550

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIP5700H

  Date Added:

  September 29, 2026

  Manufacturer:

  CHEVROLET

  Summary

  This PI communicates the proper part numbers for transmission connectors and internal harness to prevent confusion when ordering

  Associated Products (75)

  2023 Cadillac CT42023 Chevrolet Camaro2023 Chevrolet Express2023 Chevrolet Silverado2023 GMC Sierra2022 Cadillac CT42022 Chevrolet Camaro2022 Chevrolet Colorado2022 Chevrolet Silverado2022 GMC Canyon2022 GMC Sierra2021 Cadillac CT42021 Chevrolet Camaro2021 Chevrolet Colorado2021 Chevrolet Express2021 Chevrolet Silverado2021 GMC Canyon2021 GMC Sierra2020 Cadillac CT42020 Chevrolet Camaro+ 55 more
  Associated Documents

  • DownloadMC-11037550-0001.pdf↗
• September 8, 2026•Document ID: 11037319

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIC6555A

  Date Added:

  September 16, 2026

  Manufacturer:

  CADILLAC

  Summary

  This PI advises of a procedure for a Service Door Latch System message with No Related DTCs

  Associated Products (14)

  2026 Cadillac CT42026 Cadillac CT52025 Cadillac CT42025 Cadillac CT52024 Cadillac CT42024 Cadillac CT52023 Cadillac CT42023 Cadillac CT52022 Cadillac CT42022 Cadillac CT52021 Cadillac CT42021 Cadillac CT52020 Cadillac CT42020 Cadillac CT5
  Associated Documents

  • DownloadMC-11037319-0001.pdf↗
• September 4, 2026•Document ID: 11037253

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIP4902W

  Date Added:

  September 10, 2026

  Manufacturer:

  CHEVROLET

  Summary

  This preliminary information advises a dealer on how to email GDS2 session logs into Technical Assistance.

  Associated Products (751)

  2027 Buick Enclave2027 Buick Encore GX2027 Cadillac Escalade IQ2027 Cadillac Escalade IQL2027 Cadillac Lyriq2027 Cadillac Optiq2027 Cadillac Vistiq2027 Chevrolet Blazer2027 Chevrolet Bolt EV2027 Chevrolet Corvette2027 Chevrolet Equinox2027 Chevrolet Trailblazer2027 Chevrolet Traverse2027 GMC Acadia2027 GMC Terrain2026 Buick Enclave2026 Buick Encore2026 Buick Encore GX2026 Buick Envision2026 Buick Envista+ 731 more
  Associated Documents

  • DownloadMC-11037253-0001.pdf↗
• August 20, 2026•Document ID: 11036392

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIC6551C

  Date Added:

  August 27, 2026

  Manufacturer:

  CADILLAC

  Summary

  This Preliminary information communicates to dealer to perform a MEC reset for wireless projection issues

  Associated Products (233)

  2026 Buick Enclave2026 Buick Encore2026 Buick Encore GX2026 Buick Envision2026 Buick Envista2026 Cadillac Celestiq2026 Cadillac CT42026 Cadillac CT52026 Cadillac Escalade2026 Cadillac Escalade ESV2026 Cadillac Escalade IQ2026 Cadillac Escalade IQL2026 Cadillac Lyriq2026 Cadillac Optiq2026 Cadillac Vistiq2026 Cadillac XT42026 Cadillac XT52026 Cadillac XT62026 Chevrolet Blazer2026 Chevrolet BrightDrop+ 213 more
  Associated Documents

  • DownloadMC-11036392-0001.pdf↗
• July 28, 2026•Document ID: 11035693

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT6110K

  Date Added:

  August 4, 2026

  Manufacturer:

  CHEVROLET

  Summary

  This Preliminary information communicates an issue with the SES MIL and DTC P062B and engineering is currently investigating.

  Associated Products (84)

  2027 Buick Encore GX2027 Chevrolet Trailblazer2026 Buick Encore GX2026 Buick Envision2026 Cadillac CT42026 Cadillac CT52026 Cadillac Escalade2026 Cadillac Escalade ESV2026 Cadillac XT52026 Chevrolet Blazer2026 Chevrolet Colorado2026 Chevrolet Express2026 Chevrolet Silverado2026 Chevrolet Suburban2026 Chevrolet Tahoe2026 Chevrolet Trailblazer2026 GMC Canyon2026 GMC Savana2026 GMC Sierra2026 GMC Yukon+ 64 more
  Associated Documents

  • DownloadMC-11035693-0001.pdf↗
• July 24, 2026•Document ID: 11035351

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT6446A

  Date Added:

  July 30, 2026

  Manufacturer:

  CADILLAC

  Summary

  This PI Communicates information to ensure Memory Recall is enabled to ensure memory mirrors return to set position after curbview assist is used.

  Associated Products (67)

  2026 Cadillac CT42026 Cadillac Escalade2026 Cadillac Escalade ESV2026 Cadillac Escalade IQ2026 Cadillac Lyriq2026 Chevrolet Silverado2026 Chevrolet Suburban2026 Chevrolet Tahoe2026 GMC Hummer EV Pickup2026 GMC Hummer EV SUV2026 GMC Sierra2026 GMC Yukon2026 GMC Yukon XL2025 Cadillac CT42025 Cadillac Escalade2025 Cadillac Escalade ESV2025 Cadillac Escalade IQ2025 Cadillac Lyriq2025 Chevrolet Silverado2025 Chevrolet Suburban+ 47 more
  Associated Documents

  • DownloadMC-11035351-0001.pdf↗
• July 21, 2026•Document ID: 11035340

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT5099J

  Date Added:

  July 29, 2026

  Manufacturer:

  CHEVROLET

  Summary

  PI to help diagnose A/C concern

  Associated Products (505)

  2026 Buick Enclave2026 Buick Encore2026 Buick Encore GX2026 Buick Envision2026 Buick Envista2026 Cadillac Celestiq2026 Cadillac CT42026 Cadillac CT52026 Cadillac Escalade2026 Cadillac Escalade ESV2026 Cadillac Escalade IQ2026 Cadillac Escalade IQL2026 Cadillac Lyriq2026 Cadillac Optiq2026 Cadillac Vistiq2026 Cadillac XT42026 Cadillac XT52026 Cadillac XT62026 Chevrolet Blazer2026 Chevrolet BrightDrop+ 485 more
  Associated Documents

  • DownloadMC-11035340-0001.pdf↗
• June 23, 2026•Document ID: 11034769

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT5966F

  Date Added:

  July 7, 2026

  Manufacturer:

  CHEVROLET

  Summary

  This Preliminary information communicates an issue with an OTA pending message still displayed after an OTA event and how to reset/clear the message.

  Associated Products (232)

  2026 Buick Enclave2026 Buick Encore2026 Buick Encore GX2026 Buick Envision2026 Buick Envista2026 Cadillac Celestiq2026 Cadillac CT42026 Cadillac CT52026 Cadillac Escalade2026 Cadillac Escalade ESV2026 Cadillac Escalade IQ2026 Cadillac Escalade IQL2026 Cadillac Lyriq2026 Cadillac Optiq2026 Cadillac Vistiq2026 Cadillac XT42026 Cadillac XT52026 Cadillac XT62026 Chevrolet Blazer2026 Chevrolet BrightDrop+ 212 more
  Associated Documents

  • DownloadMC-11034769-0001.pdf↗
• May 27, 2026•Document ID: 11033150

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT6519

  Date Added:

  June 2, 2026

  Manufacturer:

  CHEVROLET

  Summary

  This preliminary information is to inform technicians and customers that the voice command will be inoperative when trying to open applications. Engineering is investigating and this PI will be converted to a bulletin when a repair is available.

  Associated Products (170)

  2027 Chevrolet Bolt EV2027 Chevrolet Corvette2026 Buick Enclave2026 Buick Encore2026 Buick Encore GX2026 Buick Envision2026 Cadillac Celestiq2026 Cadillac CT42026 Cadillac CT52026 Cadillac Escalade2026 Cadillac Escalade ESV2026 Cadillac Escalade IQ2026 Cadillac Escalade IQL2026 Cadillac Lyriq2026 Cadillac Optiq2026 Cadillac XT42026 Cadillac XT52026 Cadillac XT62026 Chevrolet Blazer2026 Chevrolet BrightDrop+ 150 more
  Associated Documents

  • DownloadMC-11033150-0001.pdf↗
• May 21, 2026•Document ID: 11032955

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIP6115

  Date Added:

  May 28, 2026

  Manufacturer:

  CHEVROLET

  Summary

  The document advise technicians after an engine repair involving removal of the camshaft actuators, the vehicle may set p1101 P0172 and or stalls when taken off idle. The technician is instructed to verify the intake and exhaust camshaft actuators are installed onto the correct camshafts.

  Associated Products (31)

  2026 Cadillac CT42026 Chevrolet Colorado2026 Chevrolet Silverado2026 GMC Canyon2026 GMC Sierra2025 Cadillac CT42025 Chevrolet Colorado2025 Chevrolet Silverado2025 GMC Canyon2025 GMC Sierra2024 Cadillac CT42024 Chevrolet Colorado2024 Chevrolet Silverado2024 GMC Canyon2024 GMC Sierra2023 Cadillac CT42023 Chevrolet Colorado2023 Chevrolet Silverado2023 GMC Canyon2023 GMC Sierra+ 11 more
  Associated Documents

  • DownloadMC-11032955-0001.pdf↗
• May 21, 2026•Document ID: 11032952

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT6215C

  Date Added:

  May 28, 2026

  Manufacturer:

  GMC

  Summary

  This Preliminary information communicates to dealership technicians that if they encounter a customer vehicle with this concern, to perform the steps listed and should be able to reprogram the module and correct this.

  Associated Products (73)

  2026 Cadillac CT42026 Cadillac CT52026 Cadillac Escalade2026 Cadillac Escalade ESV2026 Cadillac Escalade IQ2026 Cadillac Escalade IQL2026 Cadillac Lyriq2026 Cadillac Optiq2026 Cadillac Vistiq2026 Chevrolet Blazer2026 Chevrolet BrightDrop2026 Chevrolet Colorado2026 Chevrolet Corvette2026 Chevrolet Equinox2026 Chevrolet Silverado2026 Chevrolet Suburban2026 Chevrolet Tahoe2026 GMC Canyon2026 GMC Hummer EV Pickup2026 GMC Hummer EV SUV+ 53 more
  Associated Documents

  • DownloadMC-11032952-0001.pdf↗
• May 14, 2026•Document ID: 11032784

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIC6540J

  Date Added:

  May 19, 2026

  Manufacturer:

  CHEVROLET

  Summary

  This Preliminary information communicates to dealers a procedure to reset the radio.

  Associated Products (153)

  2027 Chevrolet Bolt EV2026 Buick Enclave2026 Buick Encore2026 Buick Encore GX2026 Buick Envision2026 Buick Envista2026 Cadillac Celestiq2026 Cadillac CT42026 Cadillac CT52026 Cadillac Escalade2026 Cadillac Escalade ESV2026 Cadillac Escalade IQ2026 Cadillac Escalade IQL2026 Cadillac Lyriq2026 Cadillac Optiq2026 Cadillac Vistiq2026 Cadillac XT42026 Cadillac XT52026 Cadillac XT62026 Chevrolet Blazer+ 133 more
  Associated Documents

  • DownloadMC-11032784-0001.pdf↗
• May 11, 2026•Document ID: 11032770

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT6513

  Date Added:

  May 19, 2026

  Manufacturer:

  BUICK

  Summary

  This PI states that if SDGM DTC U3000 Sym 49 is set and no other SDGM DTCs are present, clear DTCs and reset the SDGM. Advises of how to contact PQC to authorize SDGM replacement.

  Associated Products (35)

  2026 Cadillac CT42026 Chevrolet Silverado2026 GMC Sierra2025 Cadillac CT42025 Chevrolet Silverado2025 GMC Sierra2024 Cadillac CT42024 Cadillac CT52024 Cadillac Escalade2024 Cadillac Escalade ESV2024 Chevrolet Silverado2024 Chevrolet Tahoe2024 GMC Sierra2024 GMC Yukon2024 GMC Yukon XL2023 Buick Envision2023 Cadillac CT42023 Cadillac CT52023 Cadillac Escalade2023 Cadillac Escalade ESV+ 15 more
  Associated Documents

  • DownloadMC-11032770-0001.pdf↗
• May 11, 2026•Document ID: 11032767

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIC6540H

  Date Added:

  May 19, 2026

  Manufacturer:

  GMC

  Summary

  This Preliminary information communicates to dealers a procedure to reset the radio.

  Associated Products (153)

  2027 Chevrolet Bolt EV2026 Buick Enclave2026 Buick Encore2026 Buick Encore GX2026 Buick Envision2026 Buick Envista2026 Cadillac Celestiq2026 Cadillac CT42026 Cadillac CT52026 Cadillac Escalade2026 Cadillac Escalade ESV2026 Cadillac Escalade IQ2026 Cadillac Escalade IQL2026 Cadillac Lyriq2026 Cadillac Optiq2026 Cadillac Vistiq2026 Cadillac XT42026 Cadillac XT52026 Cadillac XT62026 Chevrolet Blazer+ 133 more
  Associated Documents

  • DownloadMC-11032767-0001.pdf↗
• May 11, 2026•Document ID: 11032764

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIC6423A

  Date Added:

  May 19, 2026

  Manufacturer:

  BUICK

  Summary

  Pi created to provide GM dealers with information on gathering information for projection issue

  Associated Products (232)

  2026 Buick Enclave2026 Buick Encore2026 Buick Encore GX2026 Buick Envision2026 Buick Envista2026 Cadillac Celestiq2026 Cadillac CT42026 Cadillac CT52026 Cadillac Escalade2026 Cadillac Escalade ESV2026 Cadillac Escalade IQ2026 Cadillac Escalade IQL2026 Cadillac Lyriq2026 Cadillac Optiq2026 Cadillac Vistiq2026 Cadillac XT42026 Cadillac XT52026 Cadillac XT62026 Chevrolet Blazer2026 Chevrolet BrightDrop+ 212 more
  Associated Documents

  • DownloadMC-11032764-0001.pdf↗
• May 11, 2026•Document ID: 11032763

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIC6551B

  Date Added:

  May 19, 2026

  Manufacturer:

  CADILLAC

  Summary

  This Preliminary information communicates to dealer to perform a MEC reset for wireless projection issues

  Associated Products (232)

  2026 Buick Enclave2026 Buick Encore2026 Buick Encore GX2026 Buick Envision2026 Buick Envista2026 Cadillac Celestiq2026 Cadillac CT42026 Cadillac CT52026 Cadillac Escalade2026 Cadillac Escalade ESV2026 Cadillac Escalade IQ2026 Cadillac Escalade IQL2026 Cadillac Lyriq2026 Cadillac Optiq2026 Cadillac Vistiq2026 Cadillac XT42026 Cadillac XT52026 Cadillac XT62026 Chevrolet Blazer2026 Chevrolet BrightDrop+ 212 more
  Associated Documents

  • DownloadMC-11032763-0001.pdf↗