Cadillac CT4 Service Bulletins

1,208 manufacturer communications on file.

• June 3, 2026•Document ID: 11033726

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT6503A

  Date Added:

  June 8, 2026

  Manufacturer:

  CHEVROLET

  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 (114)

  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+ 94 more
  Associated Documents

  • DownloadMC-11033726-0001.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 27, 2026•Document ID: 11032969

  Over The Air
  UNKNOWN OR OTHER

  Mfr Comm. #:

  661.10

  Date Added:

  May 28, 2026

  Manufacturer:

  CADILLAC

  Summary

  • Improvements to traction and stability control on uneven terrain • Improvements to braking performance on low-traction surfaces • Improvements to assisted braking • Improvements to active cabin ventilation • Additional protection for the health of your battery • Updates to help prevent excessive battery drain and overheating • Improvements to the software update system

  Associated Products (2)

  2026 Cadillac CT42026 Cadillac CT5
  Associated Documents

  • DownloadMC-11032969-0001.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: 11032771

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIP6101B

  Date Added:

  May 19, 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 (28)

  2026 Buick Enclave2026 Buick Envision2026 Cadillac CT42026 Cadillac CT52026 Cadillac XT42026 Cadillac XT52026 Cadillac XT62026 Chevrolet Blazer2026 Chevrolet Colorado2026 Chevrolet Silverado2026 Chevrolet Traverse2026 GMC Acadia2026 GMC Canyon2026 GMC Sierra2025 Buick Enclave2025 Buick Envision2025 Cadillac CT42025 Cadillac CT52025 Cadillac XT42025 Cadillac XT5+ 8 more
  Associated Documents

  • DownloadMC-11032771-0001.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↗
• 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 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 (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 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:

  CHEVROLET

  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:

  CHEVROLET

  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 (114)

  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+ 94 more
  Associated Documents

  • DownloadMC-11031514-0001.pdf↗