Cadillac CT4 Service Bulletins

1,009 manufacturer communications on file.

• 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 (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-11032763-0001.pdf↗
• 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:

  CHEVROLET

  Summary

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

  Associated Products (21)

  2026 Buick Encore GX2026 Cadillac CT42026 Cadillac Lyriq2026 Chevrolet Colorado2026 GMC Canyon2025 Buick Encore GX2025 Cadillac CT42025 Cadillac Lyriq2025 Cadillac XT42025 Chevrolet Colorado2025 GMC Canyon2024 Buick Encore GX2024 Cadillac CT42024 Cadillac Lyriq2024 Cadillac XT42024 Chevrolet Colorado2024 GMC Canyon2023 Buick Encore GX2023 Cadillac CT42023 Chevrolet Colorado+ 1 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:

  GMC

  Summary

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

  Associated Products (136)

  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+ 116 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 (136)

  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+ 116 more
  Associated Documents

  • DownloadMC-11032559-0001.pdf↗
• April 27, 2026•Document ID: 11031763

  Over The Air
  UNKNOWN OR OTHER

  Mfr Comm. #:

  661.10

  Date Added:

  April 30, 2026

  Manufacturer:

  CADILLAC

  Summary

  • Fixes to help ensure responsiveness for the driver display and rear view camera. Improvements to reliability for alerts and chimes.

  Associated Products (2)

  2025 Cadillac CT42025 Cadillac CT5
  Associated Documents

  • DownloadMC-11031763-0001.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 (52)

  2026 Cadillac CT42026 Cadillac CT52026 Cadillac Escalade2026 Cadillac Escalade ESV2026 Cadillac Lyriq2026 Cadillac Optiq2026 Chevrolet Tahoe2026 GMC Yukon2026 GMC Yukon XL2025 Cadillac CT42025 Cadillac CT52025 Cadillac Escalade2025 Cadillac Escalade ESV2025 Cadillac Lyriq2025 Cadillac Optiq2025 Chevrolet Tahoe2025 GMC Yukon2025 GMC Yukon XL2024 Cadillac CT42024 Cadillac CT5+ 32 more
  Associated Documents

  • DownloadMC-11031948-0001.pdf↗
• April 23, 2026•Document ID: 11031764

  Over The Air
  UNKNOWN OR OTHER

  Mfr Comm. #:

  654.51

  Date Added:

  April 30, 2026

  Manufacturer:

  CADILLAC

  Summary

  • Fixes to help ensure responsiveness for the driver display and rear view camera. Improvements to reliability for alerts and chimes.

  Associated Products (2)

  2026 Cadillac CT42026 Cadillac CT5
  Associated Documents

  • DownloadMC-11031764-0001.pdf↗
• April 20, 2026•Document ID: 11031717

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT6507

  Date Added:

  April 29, 2026

  Manufacturer:

  CADILLAC

  Summary

  This PI communicates information on a SPS programming issue causing Serial Data Authentication Configuration to fail.

  Associated Products (10)

  2021 Buick Envision2021 Cadillac CT42021 Cadillac CT52021 Cadillac Escalade2021 Cadillac Escalade ESV2021 Chevrolet Corvette2021 Chevrolet Suburban2021 Chevrolet Tahoe2021 GMC Yukon2021 GMC Yukon XL
  Associated Documents

  • DownloadMC-11031717-0001.pdf↗
• April 14, 2026•Document ID: 11031514

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT6503

  Date Added:

  April 23, 2026

  Manufacturer:

  BUICK

  Summary

  This preliminary information is to inform technicians that GM is placing the B174W Front View Camera Module (ACP2) on part restriction due to elevated replacement rates and ongoing engineering investigation. Technicians must not replace the front camera module unless they have: 1.Completed the diagnostic procedure in this PI, and 2.Contacted TAC and received authorization, including the SI document number and specific step that directs camera replacement.

  Associated Products (101)

  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+ 81 more
  Associated Documents

  • DownloadMC-11031514-0001.pdf↗
• April 1, 2026•Document ID: 11030974

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT3271Q

  Date Added:

  April 7, 2026

  Manufacturer:

  CHEVROLET

  Summary

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

  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-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:

  CADILLAC

  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 (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-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 (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-11030091-0001.pdf↗
• March 3, 2026•Document ID: 11029264

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIP6101A

  Date Added:

  March 3, 2026

  Manufacturer:

  CADILLAC

  Summary

  The document makes technicians aware of a valvetrain tick noise that is created by one or more soft hydraulic valve lash adjusters. The soft lash adjuster concern is due to debris from the valve rocker arm, entering into the lash adjuster. The document instructs the technician to replace all of the lash adjusters and rocker arms in the entire engine if any soft lash adjusters are found.

  Associated Products (24)

  2026 Buick Enclave2026 Buick Envista2026 Cadillac CT42026 Cadillac CT52026 Cadillac XT42026 Cadillac XT52026 Cadillac XT62026 Chevrolet Blazer2026 Chevrolet Colorado2026 Chevrolet Traverse2026 GMC Acadia2026 GMC Canyon2025 Buick Enclave2025 Buick Envista2025 Cadillac CT42025 Cadillac CT52025 Cadillac XT42025 Cadillac XT52025 Cadillac XT62025 Chevrolet Blazer+ 4 more
  Associated Documents

  • DownloadMC-11029264-0001.pdf↗
• March 2, 2026•Document ID: 11029950

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT6425D

  Date Added:

  March 11, 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'ss

  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-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:

  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 (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-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:

  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 (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-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 (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:

  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 (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↗