Cadillac CT4 Service Bulletins (2021)

814 manufacturer communications on file.

• January 30, 2026•Document ID: 11027949

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIP5921B

  Date Added:

  February 1, 2026

  Manufacturer:

  CADILLAC

  Summary

  This Preliminary information communicates the possibility of DTC p0011 p0016 and potential for a rattle or ticking noise to occur from the Intake Cam Actuator, or cover plate screws backing out and making contact with Cam carrier

  Associated Products (3)

  2023 Cadillac CT42022 Cadillac CT42021 Cadillac CT4
  Associated Documents

  • DownloadMC-11027949-0001.pdf↗
• January 29, 2026•Document ID: 11027942

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIP5865K

  Date Added:

  February 1, 2026

  Manufacturer:

  CADILLAC

  Summary

  This Preliminary information communicates the possibility of DTC P30BF failing on low mile vehicles due to the possibility of the cylinder 1/2 sliding barrel binding on intake camshaft.

  Associated Products (14)

  2026 Cadillac CT42026 Chevrolet Colorado2026 GMC Canyon2025 Cadillac CT42025 Chevrolet Colorado2025 GMC Canyon2024 Cadillac CT42024 Chevrolet Colorado2024 GMC Canyon2023 Cadillac CT42023 Chevrolet Colorado2023 GMC Canyon2022 Cadillac CT42021 Cadillac CT4
  Associated Documents

  • DownloadMC-11027942-0001.pdf↗
• January 27, 2026•Document ID: 11027932

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT5985K

  Date Added:

  February 1, 2026

  Manufacturer:

  CHEVROLET

  Summary

  This PI provides diagnostics tips to dealership techs when trying to diagnose a CAN Bus communication issue after an event like a lightning strike, battery jump started backwards, failure over the air update, etc.

  Associated Products (85)

  2026 Buick Enclave2026 Buick Envision2026 Cadillac CT42026 Cadillac CT52026 Cadillac Escalade2026 Cadillac Escalade ESV2026 Cadillac Escalade IQ2026 Cadillac Escalade IQL2026 Chevrolet Colorado2026 Chevrolet Equinox2026 Chevrolet Tahoe2026 Chevrolet Traverse2026 GMC Acadia2026 GMC Canyon2026 GMC Hummer EV Pickup2026 GMC Hummer EV SUV2026 GMC Yukon2026 GMC Yukon XL2025 Buick Enclave2025 Buick Envision+ 65 more
  Associated Documents

  • DownloadMC-11027932-0001.pdf↗
• January 16, 2026•Document ID: 11027697

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT6425C

  Date Added:

  January 19, 2026

  Manufacturer:

  BUICK

  Summary

  This Preliminary information communicates to the field on how to diagnosis a GPS issue with the Telematic module with no DTC's

  Associated Products (210)

  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 Colorado+ 190 more
  Associated Documents

  • DownloadMC-11027697-0001.pdf↗
• January 14, 2026•Document ID: 11027701

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIP6098

  Date Added:

  January 19, 2026

  Manufacturer:

  CADILLAC

  Summary

  This PI advised dealer technicians of possible causes of diesel fuel contamination in gasoline powered vehicles and advises of warranty direction.

  Associated Products (210)

  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 Colorado+ 190 more
  Associated Documents

  • DownloadMC-11027701-0001.pdf↗
• January 12, 2026•Document ID: 11027689

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIP5700G

  Date Added:

  January 19, 2026

  Manufacturer:

  CADILLAC

  Summary

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

  Associated Products (17)

  2023 Cadillac CT42023 Chevrolet Camaro2023 Chevrolet Express2023 GMC Savana2022 Cadillac CT42022 Chevrolet Camaro2022 Chevrolet Colorado2022 Chevrolet Equinox2022 Chevrolet Express2022 GMC Canyon2022 GMC Savana2021 Cadillac CT42021 Chevrolet Camaro2021 Chevrolet Colorado2021 Chevrolet Express2021 GMC Canyon2021 GMC Savana
  Associated Documents

  • DownloadMC-11027689-0001.pdf↗
• January 10, 2026•Document ID: 11027617

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIP5841G

  Date Added:

  January 14, 2026

  Manufacturer:

  GMC

  Summary

  This Preliminary information communicates the potential for condensation to freeze up inside the Crankcase Pressure Sensor causing dtc P04FB to set.

  Associated Products (38)

  2025 Buick Envision2025 Cadillac CT42025 Cadillac CT52025 Cadillac XT42025 Cadillac XT52025 Cadillac XT62025 Chevrolet Blazer2024 Buick Envision2024 Cadillac CT42024 Cadillac CT52024 Cadillac XT42024 Cadillac XT52024 Cadillac XT62024 Chevrolet Blazer2023 Buick Envision2023 Cadillac CT42023 Cadillac CT52023 Cadillac XT42023 Cadillac XT52023 Cadillac XT6+ 18 more
  Associated Documents

  • DownloadMC-11027617-0001.pdf↗
• January 10, 2026•Document ID: 11027615

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT6369B

  Date Added:

  January 14, 2026

  Manufacturer:

  CADILLAC

  Summary

  This Preliminary information communicates to dealership technicians to perform the reset for the 2 modules noted above.

  Associated Products (44)

  2026 Buick Encore2026 Cadillac CT42025 Buick Encore2025 Cadillac CT42025 Chevrolet Corvette2025 Chevrolet Tahoe2025 GMC Hummer EV Pickup2025 GMC Hummer EV SUV2024 Buick Encore2024 Cadillac CT42024 Cadillac CT52024 Cadillac Escalade2024 Cadillac Escalade ESV2024 Chevrolet Corvette2024 Chevrolet Tahoe2024 GMC Hummer EV Pickup2024 GMC Hummer EV SUV2024 GMC Yukon2024 GMC Yukon XL2023 Buick Encore+ 24 more
  Associated Documents

  • DownloadMC-11027615-0001.pdf↗
• January 8, 2026•Document ID: 11027601

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIP4902U

  Date Added:

  January 13, 2026

  Manufacturer:

  CHEVROLET

  Summary

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

  Associated Products (210)

  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 Colorado+ 190 more
  Associated Documents

  • DownloadMC-11027601-0001.pdf↗
• December 17, 2025•Document ID: 11026720

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIP6093

  Date Added:

  December 22, 2025

  Manufacturer:

  CADILLAC

  Summary

  This Preliminary information communicates the potential for condensation to freeze up inside the Crankcase Pressure Sensor causing dtc P04FB to set.

  Associated Products (8)

  2022 Buick Envision2022 Cadillac CT42022 Cadillac CT52022 Cadillac XT42021 Buick Envision2021 Cadillac CT42021 Cadillac CT52021 Cadillac XT4
  Associated Documents

  • DownloadMC-11026720-0001.pdf↗
• November 20, 2025•Document ID: 11025755

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT5214G

  Date Added:

  November 28, 2025

  Manufacturer:

  CADILLAC

  Summary

  This Preliminary Information communication provides information to the technician about vehicles that have had multiple repair attempts that are being performed on customer’s vehicles that exhibit vibration conditions without utilizing the support of General Motors Technical Assistance Center. If valid vibration frequency or Road Force Variation data has been collected and a repair attempt does not correct the customer complaint, contact General Motors Technical Assistance Center for further support. For any vehicles that remains unrepaired after being at the dealer for three days or more and a related bulletin or PI is not found, contact General Motors Technical Assistance Center for further support.

  Associated Products (210)

  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 Colorado+ 190 more
  Associated Documents

  • DownloadMC-11025755-0001.pdf↗
• November 7, 2025•Document ID: 11025462

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIP5865J

  Date Added:

  November 10, 2025

  Manufacturer:

  CHEVROLET

  Summary

  This Preliminary information communicates the possibility of DTC P30BF failing on low mile vehicles due to the possibility of the cylinder 1/2 sliding barrel binding on intake camshaft.

  Associated Products (14)

  2026 Cadillac CT42026 Chevrolet Colorado2026 GMC Canyon2025 Cadillac CT42025 Chevrolet Colorado2025 GMC Canyon2024 Cadillac CT42024 Chevrolet Colorado2024 GMC Canyon2023 Cadillac CT42023 Chevrolet Colorado2023 GMC Canyon2022 Cadillac CT42021 Cadillac CT4
  Associated Documents

  • DownloadMC-11025462-0001.pdf↗
• November 3, 2025•Document ID: 11025453

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT6446

  Date Added:

  November 10, 2025

  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 (48)

  2026 Cadillac CT42026 Cadillac Escalade ESV2026 Cadillac Escalade IQ2026 Cadillac Lyriq2026 Chevrolet Tahoe2026 GMC Hummer EV Pickup2026 GMC Hummer EV SUV2026 GMC Yukon2026 GMC Yukon XL2025 Cadillac CT42025 Cadillac Escalade ESV2025 Cadillac Escalade IQ2025 Cadillac Lyriq2025 Chevrolet Tahoe2025 GMC Hummer EV Pickup2025 GMC Hummer EV SUV2025 GMC Yukon2025 GMC Yukon XL2024 Cadillac CT42024 Cadillac Escalade ESV+ 28 more
  Associated Documents

  • DownloadMC-11025453-0001.pdf↗
• October 30, 2025•Document ID: 11024777

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIP5700F

  Date Added:

  November 3, 2025

  Manufacturer:

  CHEVROLET

  Summary

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

  Associated Products (17)

  2023 Cadillac CT42023 Chevrolet Camaro2023 Chevrolet Express2023 GMC Savana2022 Cadillac CT42022 Chevrolet Camaro2022 Chevrolet Colorado2022 Chevrolet Equinox2022 Chevrolet Express2022 GMC Canyon2022 GMC Savana2021 Cadillac CT42021 Chevrolet Camaro2021 Chevrolet Colorado2021 Chevrolet Express2021 GMC Canyon2021 GMC Savana
  Associated Documents

  • DownloadMC-11024777-0001.pdf↗
• October 29, 2025•Document ID: 11024768

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT6446

  Date Added:

  November 3, 2025

  Manufacturer:

  GMC

  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 (54)

  2026 Cadillac CT42026 Cadillac Escalade2026 Cadillac Escalade ESV2026 Cadillac Escalade IQ2026 Cadillac Lyriq2026 Chevrolet Tahoe2026 GMC Hummer EV Pickup2026 GMC Hummer EV SUV2026 GMC Yukon2026 GMC Yukon XL2025 Cadillac CT42025 Cadillac Escalade2025 Cadillac Escalade ESV2025 Cadillac Escalade IQ2025 Cadillac Lyriq2025 Chevrolet Tahoe2025 GMC Hummer EV Pickup2025 GMC Hummer EV SUV2025 GMC Yukon2025 GMC Yukon XL+ 34 more
  Associated Documents

  • DownloadMC-11024768-0001.pdf↗
• October 18, 2025•Document ID: 11024460

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT6425B

  Date Added:

  October 24, 2025

  Manufacturer:

  CHEVROLET

  Summary

  This Preliminary information communicates to the field on how to diagnosis a GPS issue with the Telematic module with no DTC's

  Associated Products (210)

  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 Colorado+ 190 more
  Associated Documents

  • DownloadMC-11024460-0001.pdf↗
• October 17, 2025•Document ID: 11024455

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT6425A

  Date Added:

  October 24, 2025

  Manufacturer:

  CHEVROLET

  Summary

  This Preliminary information communicates to the field on how to diagnosis a GPS issue with the Telematic module with no DTC's

  Associated Products (210)

  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 Colorado+ 190 more
  Associated Documents

  • DownloadMC-11024455-0001.pdf↗
• October 16, 2025•Document ID: 11024458

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIC6551A

  Date Added:

  October 24, 2025

  Manufacturer:

  CHEVROLET

  Summary

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

  Associated Products (176)

  2025 Buick Enclave2025 Buick Encore2025 Buick Encore GX2025 Buick Envision2025 Buick Envista2025 Cadillac Celestiq2025 Cadillac CT42025 Cadillac CT52025 Cadillac Escalade2025 Cadillac Escalade ESV2025 Cadillac Escalade IQ2025 Cadillac Lyriq2025 Cadillac Optiq2025 Cadillac XT42025 Cadillac XT52025 Cadillac XT62025 Chevrolet Blazer2025 Chevrolet Colorado2025 Chevrolet Corvette2025 Chevrolet Equinox+ 156 more
  Associated Documents

  • DownloadMC-11024458-0001.pdf↗
• October 8, 2025•Document ID: 11024446

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIP6088

  Date Added:

  October 24, 2025

  Manufacturer:

  CHEVROLET

  Summary

  This PI Addresses a possible solenoid wiring fault and how to inspect the build date to identify

  Associated Products (13)

  2023 Cadillac CT42023 Chevrolet Camaro2023 GMC Savana2022 Cadillac CT42022 Chevrolet Camaro2022 Chevrolet Colorado2022 GMC Canyon2022 GMC Savana2021 Cadillac CT42021 Chevrolet Camaro2021 Chevrolet Colorado2021 GMC Canyon2021 GMC Savana
  Associated Documents

  • DownloadMC-11024446-0001.pdf↗
• October 4, 2025•Document ID: 11024439

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT6440

  Date Added:

  October 24, 2025

  Manufacturer:

  CADILLAC

  Summary

  The Driver Information Center may display a message of Transport Mode On after the ignition is cycled.

  Associated Products (210)

  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 Colorado+ 190 more
  Associated Documents

  • DownloadMC-11024439-0001.pdf↗