Cadillac CT4 Service Bulletins (2023)

554 manufacturer communications on file.

• May 7, 2026•Document ID: 11032438

  Service Campaign
  ENGINE

  Mfr Comm. #:

  N262552610

  Date Added:

  May 7, 2026

  Manufacturer:

  CADILLAC

  Summary

  Certain vehicles may have a condition that could cause the crankcase pressure sensor to fail. If this failure occurs, the Malfunction Indicator Light (Check Engine Light) will illuminate and a diagnostic trouble code will set. This special coverage covers the 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 May 6, 2026, 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 May 6, 2026, 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 replace the crankcase pressure sensor as necessary. The repairs will be made at no charge to the customer.

  Associated Products (2)

  2023 Cadillac CT42023 Cadillac CT5
  Associated Documents

  • DownloadMC-11032438-0001.pdf↗
• May 6, 2026•Document ID: 11032619

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIC6566C

  Date Added:

  May 13, 2026

  Manufacturer:

  CADILLAC

  Summary

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

  Associated Products (29)

  2026 Buick Encore GX2026 Cadillac CT42026 Cadillac Lyriq2026 Chevrolet Blazer2026 Chevrolet Colorado2026 Chevrolet Silverado2026 GMC Canyon2025 Buick Encore GX2025 Cadillac CT42025 Cadillac Lyriq2025 Cadillac XT42025 Chevrolet Blazer2025 Chevrolet BrightDrop2025 Chevrolet Colorado2025 Chevrolet Silverado2025 GMC Canyon2024 BrightDrop Zevo2024 Buick Encore GX2024 Cadillac CT42024 Cadillac Lyriq+ 9 more
  Associated Documents

  • DownloadMC-11032619-0001.pdf↗
• April 30, 2026•Document ID: 11032560

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIC6540G

  Date Added:

  May 8, 2026

  Manufacturer:

  BUICK

  Summary

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

  Associated Products (152)

  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+ 132 more
  Associated Documents

  • DownloadMC-11032560-0001.pdf↗
• April 30, 2026•Document ID: 11032559

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIC6540G

  Date Added:

  May 8, 2026

  Manufacturer:

  CADILLAC

  Summary

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

  Associated Products (152)

  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+ 132 more
  Associated Documents

  • DownloadMC-11032559-0001.pdf↗
• April 25, 2026•Document ID: 11031948

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT6511

  Date Added:

  May 2, 2026

  Manufacturer:

  CADILLAC

  Summary

  This Preliminary information communicates an issue with a replace or low FOB battery message

  Associated Products (66)

  2026 Cadillac CT42026 Cadillac CT52026 Cadillac Escalade2026 Cadillac Escalade ESV2026 Cadillac Lyriq2026 Cadillac Optiq2026 Chevrolet Silverado2026 Chevrolet Suburban2026 Chevrolet Tahoe2026 GMC Sierra2026 GMC Yukon2026 GMC Yukon XL2025 Cadillac CT42025 Cadillac CT52025 Cadillac Escalade2025 Cadillac Escalade ESV2025 Cadillac Lyriq2025 Cadillac Optiq2025 Chevrolet Silverado2025 Chevrolet Suburban+ 46 more
  Associated Documents

  • DownloadMC-11031948-0001.pdf↗
• April 1, 2026•Document ID: 11030974

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT3271Q

  Date Added:

  April 7, 2026

  Manufacturer:

  CADILLAC

  Summary

  This preliminary information communicates information about how to determine if a wheel and tires size change is available.

  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-11030974-0001.pdf↗
• March 9, 2026•Document ID: 11030092

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIP6104

  Date Added:

  March 17, 2026

  Manufacturer:

  CHEVROLET

  Summary

  This Preliminary information communicates the steps on how to save a GDS2 Session Log and upload to a Technical Assistance Case in CX Connect.

  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-11030092-0001.pdf↗
• March 9, 2026•Document ID: 11030091

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIP4902V

  Date Added:

  March 17, 2026

  Manufacturer:

  BUICK

  Summary

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

  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-11030091-0001.pdf↗
• March 2, 2026•Document ID: 11029950

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT6425D

  Date Added:

  March 11, 2026

  Manufacturer:

  CADILLAC

  Summary

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

  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-11029950-0001.pdf↗
• February 12, 2026•Document ID: 11028859

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIP5865L

  Date Added:

  February 18, 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 (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-11028859-0001.pdf↗
• February 12, 2026•Document ID: 11028856

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIP5841J

  Date Added:

  February 18, 2026

  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 (22)

  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+ 2 more
  Associated Documents

  • DownloadMC-11028856-0001.pdf↗
• February 4, 2026•Document ID: 11028658

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIP5841H

  Date Added:

  February 9, 2026

  Manufacturer:

  BUICK

  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-11028658-0001.pdf↗
• 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 (14)

  2023 Cadillac CT42023 Chevrolet Silverado2023 GMC Sierra2022 Cadillac CT42022 Chevrolet Silverado2022 GMC Sierra2021 Cadillac CT42021 Chevrolet Silverado2021 GMC Sierra2020 Cadillac CT42020 Chevrolet Silverado2020 GMC Sierra2019 Chevrolet Silverado2019 GMC Sierra
  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 (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-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 (113)

  2026 Buick Enclave2026 Buick Envision2026 Cadillac CT42026 Cadillac CT52026 Cadillac Escalade2026 Cadillac Escalade ESV2026 Cadillac Escalade IQ2026 Cadillac Escalade IQL2026 Chevrolet BrightDrop2026 Chevrolet Colorado2026 Chevrolet Corvette2026 Chevrolet Equinox2026 Chevrolet Silverado2026 Chevrolet Suburban2026 Chevrolet Tahoe2026 Chevrolet Traverse2026 GMC Acadia2026 GMC Canyon2026 GMC Hummer EV Pickup2026 GMC Hummer EV SUV+ 93 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 (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-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:

  CHEVROLET

  Summary

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

  Associated Products (279)

  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+ 259 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:

  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 12, 2026•Document ID: 11027686

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT6457B

  Date Added:

  January 19, 2026

  Manufacturer:

  BUICK

  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 (152)

  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+ 132 more
  Associated Documents

  • DownloadMC-11027686-0001.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↗