Cadillac CT4 Service Bulletins (2020)

888 manufacturer communications on file.

• January 12, 2026•Document ID: 11027689

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIP5700G

  Date Added:

  January 19, 2026

  Manufacturer:

  GMC

  Summary

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

  Associated Products (85)

  2023 Cadillac CT42023 Chevrolet Camaro2023 Chevrolet Express2023 Chevrolet Silverado2023 GMC Savana2023 GMC Sierra2022 Cadillac CT42022 Chevrolet Camaro2022 Chevrolet Colorado2022 Chevrolet Equinox2022 Chevrolet Express2022 Chevrolet Silverado2022 GMC Canyon2022 GMC Savana2022 GMC Sierra2021 Cadillac CT42021 Chevrolet Camaro2021 Chevrolet Colorado2021 Chevrolet Express2021 Chevrolet Silverado+ 65 more
  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 (47)

  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+ 27 more
  Associated Documents

  • DownloadMC-11027617-0001.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 (735)

  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+ 715 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 (12)

  2022 Buick Envision2022 Cadillac CT42022 Cadillac CT52022 Cadillac XT42021 Buick Envision2021 Cadillac CT42021 Cadillac CT52021 Cadillac XT42020 Cadillac CT42020 Cadillac CT52020 Cadillac XT42019 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 (736)

  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+ 716 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 (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-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:

  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 (67)

  2026 Cadillac CT42026 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 Escalade ESV2025 Cadillac Escalade IQ2025 Cadillac Lyriq2025 Chevrolet Silverado2025 Chevrolet Suburban2025 Chevrolet Tahoe2025 GMC Hummer EV Pickup+ 47 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:

  GMC

  Summary

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

  Associated Products (85)

  2023 Cadillac CT42023 Chevrolet Camaro2023 Chevrolet Express2023 Chevrolet Silverado2023 GMC Savana2023 GMC Sierra2022 Cadillac CT42022 Chevrolet Camaro2022 Chevrolet Colorado2022 Chevrolet Equinox2022 Chevrolet Express2022 Chevrolet Silverado2022 GMC Canyon2022 GMC Savana2022 GMC Sierra2021 Cadillac CT42021 Chevrolet Camaro2021 Chevrolet Colorado2021 Chevrolet Express2021 Chevrolet Silverado+ 65 more
  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:

  CHEVROLET

  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-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:

  GMC

  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 (325)

  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+ 305 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:

  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 (325)

  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+ 305 more
  Associated Documents

  • DownloadMC-11024455-0001.pdf↗
• October 8, 2025•Document ID: 11024446

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIP6088

  Date Added:

  October 24, 2025

  Manufacturer:

  GMC

  Summary

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

  Associated Products (76)

  2023 Cadillac CT42023 Chevrolet Camaro2023 Chevrolet Silverado2023 GMC Savana2023 GMC Sierra2022 Cadillac CT42022 Chevrolet Camaro2022 Chevrolet Colorado2022 Chevrolet Silverado2022 GMC Canyon2022 GMC Savana2022 GMC Sierra2021 Cadillac CT42021 Chevrolet Camaro2021 Chevrolet Colorado2021 Chevrolet Silverado2021 GMC Canyon2021 GMC Savana2021 GMC Sierra2020 Cadillac CT4+ 56 more
  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 (278)

  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+ 258 more
  Associated Documents

  • DownloadMC-11024439-0001.pdf↗
• September 9, 2025•Document ID: 11023091

  Other
  UNKNOWN OR OTHER

  Mfr Comm. #:

  13598

  Date Added:

  September 10, 2025

  Manufacturer:

  GMC

  Summary

  New Vehicle Monitoring Programs Section in IVH

  Associated Products (843)

  2026 Buick Enclave2026 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 BrightDrop2026 Chevrolet Colorado+ 823 more
  Associated Documents

  • DownloadMC-11023091-0001.pdf↗
• September 8, 2025•Document ID: 11023145

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIP5865H

  Date Added:

  September 16, 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 (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-11023145-0001.pdf↗
• August 15, 2025•Document ID: 11022085

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIP5865F

  Date Added:

  August 22, 2025

  Manufacturer:

  GMC

  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 (26)

  2025 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 Sierra2022 Cadillac CT42022 Chevrolet Silverado2022 GMC Sierra2021 Cadillac CT42021 Chevrolet Silverado+ 6 more
  Associated Documents

  • DownloadMC-11022085-0001.pdf↗
• August 14, 2025•Document ID: 11022084

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIP4902T

  Date Added:

  August 22, 2025

  Manufacturer:

  GMC

  Summary

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

  Associated Products (681)

  2026 Buick Enclave2026 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 BrightDrop2026 Chevrolet Colorado+ 661 more
  Associated Documents

  • DownloadMC-11022084-0001.pdf↗
• August 7, 2025•Document ID: 11021792

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIC5650M

  Date Added:

  August 12, 2025

  Manufacturer:

  CHEVROLET

  Summary

  This Preliminary Information communication provides information to the technician about vehicles that have an intermittent no crank, no start, or start stall concern with the security light coming on. Technician may find Diagnostic Trouble Codes B3055, B3060, B3935, C0750, C0755, C0760, C0765, and/or C0775.

  Associated Products (896)

  2026 Buick Enclave2026 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 BrightDrop2026 Chevrolet Colorado+ 876 more
  Associated Documents

  • DownloadMC-11021792-0001.pdf↗
• July 28, 2025•Document ID: 11021303

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIP5865E

  Date Added:

  August 4, 2025

  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 (26)

  2025 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 Sierra2022 Cadillac CT42022 Chevrolet Silverado2022 GMC Sierra2021 Cadillac CT42021 Chevrolet Silverado+ 6 more
  Associated Documents

  • DownloadMC-11021303-0001.pdf↗
• July 23, 2025•Document ID: 11020815

  Service Campaign
  UNKNOWN OR OTHER

  Mfr Comm. #:

  N242480631-04

  Date Added:

  July 23, 2025

  Manufacturer:

  CADILLAC

  Summary

  Certain vehicles listed above, may have a condition where the transmission control valve has worn, resulting in a gradual loss of pressure within the valve. The effects can cause harsh shifting, setting a service engine soon message, reduced engine performance or P0747 diagnostic trouble code. This special coverage covers vehicles that return after TCM Update Product Safety N242480630 and have P0747 condition described above for a period of 15 years or 150,000 miles (240,000 km), whichever occurs first, from the date the vehicle was originally placed in service, regardless of ownership. For vehicles covered by Vehicle Service Contracts, all eligible claims with repair orders on or after March 6, 2025, are covered by this special coverage and must be submitted using the labor operation codes provided with this bulletin. Claims with repair orders prior to March 6, 2025, must be submitted to the Service Contract provider. Vehicle owners or lessees who paid for repairs referenced in this Special Coverage (“Customers”) are eligible for reimbursement of their reasonable and customary expenses in accordance with the procedures specified below. The conditional right to reimbursement is provided by GM solely in the interest of customer satisfaction and is personal to Customers. Customers may not assign and GM does not consent to any assignment of any Customer’s right to submit reimbursement claims, or to receive reimbursement, or any other rights granted by this Special Coverage to any third party, including but not limited to service contract providers, and this Special Coverage is not intended to and does not confer any third party beneficiary, subrogation or contribution rights, or any other rights to reimbursement, against GM, whether in law, equity or otherwise, on any third parties. Dealers are to install a new control valve body. The repairs will be made at no charge to the customer.

  Associated Products (9)

  2022 Chevrolet Camaro2021 Cadillac CT42021 Cadillac CT52021 Chevrolet Camaro2020 Cadillac CT42020 Cadillac CT52020 Cadillac CT62020 Chevrolet Camaro2019 Cadillac CT6
  Associated Documents

  • DownloadMC-11020815-0001.pdf↗