WenmarOpen by Wenmar Pro

Service bulletins for the 2021 Cadillac CT4

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

813 on file from NHTSA, as of 2026-10-19.

By type

By component

By trouble code

By topic

Bulletins, newest first
21-NA-0682023-02-07. Service bulletin. EQUIPMENT. This warranty administration bulletin provides policy information requirements applicable to key fob replacement under the New Vehicle Limited Warranty or under a Replacement Parts Warranty on 2017-2022 and newer model year vehicles with RPO ATH and AVJ.
18-NA-2792023-02-07. Service bulletin. LATCHES/LOCKS/LINKAGES. This service bulletin provides information for dealers/technicians on the process to disable and enable passive unlocking.
02-00-89-002U2023-02-06. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. This service bulletin provides information for dealers/technicians on When and How to Submit a Field Product Report (FPR) (U.S. Dealers Only).
PIT59662023-01-30. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. This Preliminary information communicates an issue with an OTA pending message still displayed after an OTA event and how to reset/clear the message.
PIP5540J2023-01-30. Service bulletin. VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM:REAR WINDOW:ELECTRICAL HEATING ELEMENT. This Preliminary information communicates to the technician the need to inspect the induction system for potential icing issues in very cold ambient temperatures. To allow the ice to melt so that it can be drained from the related components. That any of the listed DTC's may set with or without poor engine performance.
PIP5863A2023-01-30. Service bulletin. ENGINE AND ENGINE COOLING. This Preliminary information communicates to dealers? information related to a Malfunction Indicator Lamp (MIL) Illuminated due to a U0672 setting. Advises the technician to perform Electric Engine Coolant Pump connection inspections. To clear the code to see if it resets current. If the code resets it advises to utilize Strategy Based Diagnosis. If the code does not reset, it advises to release the vehicle to the customer and that GM is aware of this issue.
PIP5843A2023-01-30. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates to the dealers information related to a Malfunction Indicator Lamp (MIL) Illuminated During Cold Ambient Temperatures with DTCs P30C3 and/or P30BF P30C7 P30CB Setting.
PIP5632G2023-01-30. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE; EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. This Preliminary Information communication provides information to the technician that General Motors Technical Assistance Center may ask for Global Diagnostic System 2 Session Log. Technician will need use Global Diagnostic System 2 to send the session logs to General Motors Technical Assistance Center for further assistance on the vehicle in question.
PIP4902Q2023-01-30. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE; EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. This Preliminary Information communication provides information to the technician that General Motors Technical Assistance Center may ask for Global Diagnostic System 2 Session Log. Technician will need use Global Diagnostic System 2 to send the session logs to General Motors Technical Assistance Center for further assistance on the vehicle in question.
21-NA-1352023-01-25. Service bulletin. ELECTRICAL SYSTEM. This service bulletin provides information to inform dealership personnel about Law Enforcement and Government vehicles that request to disable or enable content.
20-NA-1872023-01-25. Service bulletin. POWER TRAIN. This service bulletin provides a repair procedure to correct a customer concern of Delayed and/or Harsh Engagement of Transmission Shift After Vehicle Sitting with Engine Off.
22-NA-1152023-01-25. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING. This service bulletin provides information for U.S. dealers ONLY to refer to the Battery Maintenance Report to identify vehicles in dealer inventory that require attention.
21-NA-1062023-01-25. Service bulletin. POWER TRAIN; ELECTRICAL SYSTEM. This service bulletin provides information for the technician that may experience a condition when after performing a DTC Clear/Reset on the TCM during diagnosis or after completion of a transmission repair or replacement, the DTCs did not clear or appear to reset on the next engine start.
20-NA-0182023-01-25. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. This service bulletin provides information for dealers/technicians on MDI 2 Required When Programming Vehicles with Vehicle Intelligence Platform (VIP).
22-NA-2572023-01-06. Service bulletin. WHEELS. This service bulletin provides information on Dealer Installed LPO Wheel Installation and Return Process.
09-00-89-008F2023-01-06. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. This Warranty Administration bulletin provides retail and wholesale service personnel with the policies/procedures and the warranty transaction submission procedures that support the Personal Property Damage process.
21-NA-1242023-01-06. Service bulletin. ENGINE AND ENGINE COOLING. This service bulletin provides diagnostic tips/steps on testing for possible EVAP leaks in the system to correct a customer concern of an MIL Illuminated with DTCs P0442 and/or P0455 Set.
18-NA-0732023-01-06. Service bulletin. ENGINE AND ENGINE COOLING. This service bulletin provides graphics, information and guidelines for engine component wear to assist service personnel as a guideline to perform necessary engine repairs and prevent unnecessary engine replacement.
16-NA-3382023-01-05. Service bulletin. POWER TRAIN; ENGINE AND ENGINE COOLING. This Warranty Admin service bulletin provides guidelines for Dealers Not Required and for Dealers Required to Contact the PQC for engine or transmission assembly replacement and explains the PQC process, GWM Transaction submission, vehicle service record retention and proper handling of assembly returns for Canadian Dealers only.
22-NA-2472022-12-24. Service bulletin. SERVICE BRAKES, HYDRAULIC. This service bulletin provides information to dealership personnel that after performing a brake inspection, brake pad replacement, or any other repair that requires the caliper piston to be reseated may be causing DTC C05B0 to falsely set for eBoost applications.
22-NA-2462022-12-23. Service bulletin. POWER TRAIN. This service bulletin advises the technician that the possible cause may not be from a faulty clutch piston or extension housing and to perform testing on transmission for possible other issues, but it still may be possible on high mile vehicles that orifices in housing may have come dislodged, causing the same customer concern.
22-NA-2442022-12-21. Service bulletin. EQUIPMENT. This service bulletin provides information about GM Accessories - Dealer-Installed, Repaired or Replaced During Warranty Coverage Period.
PIT5851C2022-12-12. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. This Preliminary information communicates an issues with the odometer being incorrect after a programming event and how the dealership can resolve the issue.
PIT3271N2022-12-12. Service bulletin. WHEELS; TIRES. This Preliminary Information communication provides information to the technician about changing the tire and wheel size on vehicles. General Motors will only support a tire calibration for tires that have been sized, tested and designed for the vehicle in question and its applications. Technician should not use the information that is provided by the antilock braking system tire size selection.
PIT5832D2022-12-12. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE. This Preliminary information communicates a diagnostic tip on how to resolve a issue if the serial data authentication configuration did not complete correctly.

The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.