Cadillac CT4 Service Bulletins (2026)

81 manufacturer communications on file.

• August 20, 2026•Document ID: 11036392

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIC6551C

  Date Added:

  August 27, 2026

  Manufacturer:

  CHEVROLET

  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-11036392-0001.pdf↗
• July 28, 2026•Document ID: 11035693

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT6110K

  Date Added:

  August 4, 2026

  Manufacturer:

  GMC

  Summary

  This Preliminary information communicates an issue with the SES MIL and DTC P062B and engineering is currently investigating.

  Associated Products (72)

  2027 Buick Encore GX2027 Chevrolet Trailblazer2026 Buick Encore GX2026 Buick Envision2026 Cadillac CT42026 Cadillac CT52026 Cadillac Escalade2026 Cadillac Escalade ESV2026 Cadillac XT52026 Chevrolet Blazer2026 Chevrolet Colorado2026 Chevrolet Express2026 Chevrolet Tahoe2026 Chevrolet Trailblazer2026 GMC Canyon2026 GMC Savana2026 GMC Yukon2026 GMC Yukon XL2025 Buick Encore GX2025 Buick Envision+ 52 more
  Associated Documents

  • DownloadMC-11035693-0001.pdf↗
• July 24, 2026•Document ID: 11035351

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT6446A

  Date Added:

  July 30, 2026

  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 (50)

  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+ 30 more
  Associated Documents

  • DownloadMC-11035351-0001.pdf↗
• July 21, 2026•Document ID: 11035340

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT5099J

  Date Added:

  July 29, 2026

  Manufacturer:

  CHEVROLET

  Summary

  PI to help diagnose A/C concern

  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-11035340-0001.pdf↗
• July 13, 2026•Document ID: 11035299

  Over The Air
  UNKNOWN OR OTHER

  Mfr Comm. #:

  662.30

  Date Added:

  July 29, 2026

  Manufacturer:

  CADILLAC

  Summary

  • Improvements to system responsiveness • Improvements to camera image clarity • Fixes to prevent blank screens and audio drop-outs • Improvements to vehicle software update installation

  Associated Products (4)

  2026 Cadillac CT42026 Cadillac CT52025 Cadillac CT42025 Cadillac CT5
  Associated Documents

  • DownloadMC-11035299-0001.pdf↗
• July 7, 2026•Document ID: 11034068

  Over The Air
  UNKNOWN OR OTHER

  Mfr Comm. #:

  662.20

  Date Added:

  June 26, 2026

  Manufacturer:

  CADILLAC

  Summary

  • Improves transmission diagnostic software. • Reduces unnecessary check

  Associated Products (4)

  2026 Cadillac CT42026 Cadillac CT52025 Cadillac CT42025 Cadillac CT5
  Associated Documents

  • DownloadMC-11034068-0001.pdf↗
• June 23, 2026•Document ID: 11034769

  Service Bulletin/Repair Instructions
  UNKNOWN OR OTHER

  Mfr Comm. #:

  PIT5966F

  Date Added:

  July 7, 2026

  Manufacturer:

  CHEVROLET

  Summary

  This Preliminary information communicates an issue with an OTA pending message still displayed after an OTA event and how to reset/clear the message.

  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-11034769-0001.pdf↗
• June 16, 2026•Document ID: 11034038

  Over The Air
  UNKNOWN OR OTHER

  Mfr Comm. #:

  N25-252332

  Date Added:

  June 24, 2026

  Manufacturer:

  GMC

  Summary

  • Fixes to help prevent loss of functionality for connectivity features such as OnStar, Wi-Fi, Navigation, and Super Cruise.

  Associated Products (25)

  2026 Buick Enclave2026 Buick Envision2026 Cadillac Celestiq2026 Cadillac CT42026 Cadillac CT52026 Cadillac Lyriq2026 Cadillac Optiq2026 Chevrolet Equinox2026 Chevrolet Traverse2026 GMC Acadia2026 GMC Terrain2025 Buick Enclave2025 Cadillac Celestiq2025 Cadillac CT42025 Cadillac CT52025 Cadillac Lyriq2025 Cadillac Optiq2025 Chevrolet Traverse2025 GMC Acadia2024 Cadillac Lyriq+ 5 more
  Associated Documents

  • DownloadMC-11034038-0001.pdf↗
• 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 (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-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:

  GMC

  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 (152)

  2026 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 Colorado2026 Chevrolet Equinox2026 Chevrolet Express+ 132 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:

  GMC

  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 (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-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:

  CHEVROLET

  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 (53)

  2026 Cadillac CT42026 Cadillac CT52026 Cadillac Escalade2026 Cadillac Escalade ESV2026 Cadillac Escalade IQ2026 Cadillac Escalade IQL2026 Cadillac Lyriq2026 Cadillac Optiq2026 Cadillac Vistiq2026 Chevrolet Colorado2026 Chevrolet Equinox2026 Chevrolet Tahoe2026 GMC Canyon2026 GMC Hummer EV Pickup2026 GMC Hummer EV SUV2026 GMC Terrain2026 GMC Yukon2026 GMC Yukon XL2025 Cadillac CT42025 Cadillac CT5+ 33 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 (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-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 (24)

  2026 Buick Enclave2026 Buick Envision2026 Cadillac CT42026 Cadillac CT52026 Cadillac XT42026 Cadillac XT52026 Cadillac XT62026 Chevrolet Blazer2026 Chevrolet Colorado2026 Chevrolet Traverse2026 GMC Acadia2026 GMC Canyon2025 Buick Enclave2025 Buick Envision2025 Cadillac CT42025 Cadillac CT52025 Cadillac XT42025 Cadillac XT52025 Cadillac XT62025 Chevrolet Blazer+ 4 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:

  CHEVROLET

  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 (27)

  2026 Cadillac CT42025 Cadillac CT42024 Cadillac CT42024 Cadillac CT52024 Cadillac Escalade2024 Cadillac Escalade ESV2024 Chevrolet Tahoe2024 GMC Yukon2024 GMC Yukon XL2023 Buick Envision2023 Cadillac CT42023 Cadillac CT52023 Cadillac Escalade2023 Cadillac Escalade ESV2023 Chevrolet Corvette2023 Chevrolet Tahoe2023 GMC Yukon2023 GMC Yukon XL2022 Buick Envision2022 Cadillac CT4+ 7 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 (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-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:

  CADILLAC

  Summary

  Pi created to provide GM dealers with information on gathering information for projection issue

  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-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 (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 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↗