2021 Cadillac CT4 Technical Service Bulletins

814 technical service bulletins (TSBs) are on record for the 2021 Cadillac CT4. TSBs are notes manufacturers send to dealers about repair procedures for issues seen in the field. They are not recalls and do not by themselves mean a vehicle has a fault.

• 11037555Sep 26, 2026Other or unknown. This PI provides Diagnostics tips on how the LIN bus works and how to diagnosis it.
• 11037550Sep 21, 2026Other or unknown. This PI communicates the proper part numbers for transmission connectors and internal harness to prevent confusion when ordering
• 11037319Sep 8, 2026Other or unknown. This PI advises of a procedure for a Service Door Latch System message with No Related DTCs
• 11037253Sep 4, 2026Other or unknown. This preliminary information advises a dealer on how to email GDS2 session logs into Technical Assistance.
• 11036392Aug 20, 2026Other or unknown. This Preliminary information communicates to dealer to perform a MEC reset for wireless projection issues
• 11035351Jul 24, 2026Other or unknown. This PI Communicates information to ensure Memory Recall is enabled to ensure memory mirrors return to set position after curbview assist is used.
• 11035340Jul 21, 2026Other or unknown. PI to help diagnose A/C concern
• 11034769Jun 23, 2026Other or unknown. This Preliminary information communicates an issue with an OTA pending message still displayed after an OTA event and how to reset/clear the message.
• 11032955May 21, 2026Other or unknown. 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.
• 11032952May 21, 2026Other or unknown. 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.
• 11032764May 11, 2026Other or unknown. Pi created to provide GM dealers with information on gathering information for projection issue
• 11032763May 11, 2026Other or unknown. This Preliminary information communicates to dealer to perform a MEC reset for wireless projection issues
• 11031948Apr 25, 2026Other or unknown. This Preliminary information communicates an issue with a replace or low FOB battery message
• 11031717Apr 20, 2026Other or unknown. This PI communicates information on a SPS programming issue causing Serial Data Authentication Configuration to fail.
• 11030974Apr 1, 2026Other or unknown. This preliminary information communicates information about how to determine if a wheel and tires size change is available.
• 11030092Mar 9, 2026Other or unknown. This Preliminary information communicates the steps on how to save a GDS2 Session Log and upload to a Technical Assistance Case in CX Connect.
• 11030091Mar 9, 2026Other or unknown. This preliminary information advises a dealer on how to email GDS2 session logs into Technical Assistance.
• 11029950Mar 2, 2026Other or unknown. This Preliminary information communicates to the field on how to diagnosis a GPS issue with the Telematic module with no DTC'ss
• 11028859Feb 12, 2026Other or unknown. 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.
• 11028658Feb 4, 2026Other or unknown. This Preliminary information communicates the potential for condensation to freeze up inside the Crankcase Pressure Sensor causing dtc P04FB to set.
• 11027949Jan 30, 2026Other or unknown. 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
• 11027942Jan 29, 2026Other or unknown. 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.
• 11027932Jan 27, 2026Other or unknown. 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.
• 11027697Jan 16, 2026Other or unknown. This Preliminary information communicates to the field on how to diagnosis a GPS issue with the Telematic module with no DTC's
• 11027701Jan 14, 2026Other or unknown. This PI advised dealer technicians of possible causes of diesel fuel contamination in gasoline powered vehicles and advises of warranty direction.
• 11027689Jan 12, 2026Other or unknown. This PI communicates the proper part numbers for transmission connectors and internal harness to prevent confusion when ordering
• 11027617Jan 10, 2026Other or unknown. This Preliminary information communicates the potential for condensation to freeze up inside the Crankcase Pressure Sensor causing dtc P04FB to set.
• 11027615Jan 10, 2026Other or unknown. This Preliminary information communicates to dealership technicians to perform the reset for the 2 modules noted above.
• 11027601Jan 8, 2026Other or unknown. This preliminary information advises a dealer on how to email GDS2 session logs into Technical Assistance.
• 11026720Dec 17, 2025Other or unknown. This Preliminary information communicates the potential for condensation to freeze up inside the Crankcase Pressure Sensor causing dtc P04FB to set.
• 11025755Nov 20, 2025Other or unknown. This Preliminary Information communication provides information to the technician about vehicles that have had multiple repair attempts that are being performed on customer’s vehicles that exhibit vibration conditions without utilizing the support of General Motors Technical Assistance Center.
• 11025462Nov 7, 2025Other or unknown. 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.
• 11025453Nov 3, 2025Other or unknown. This PI Communicates information to ensure Memory Recall is enabled to ensure memory mirrors return to set position after curbview assist is used.
• 11024777Oct 30, 2025Other or unknown. This PI communicates the proper part numbers for transmission connectors and internal harness to prevent confusion when ordering
• 11024768Oct 29, 2025Other or unknown. This PI Communicates information to ensure Memory Recall is enabled to ensure memory mirrors return to set position after curbview assist is used.
• 11024460Oct 18, 2025Other or unknown. This Preliminary information communicates to the field on how to diagnosis a GPS issue with the Telematic module with no DTC's
• 11024455Oct 17, 2025Other or unknown. This Preliminary information communicates to the field on how to diagnosis a GPS issue with the Telematic module with no DTC's
• 11024458Oct 16, 2025Other or unknown. This Preliminary information communicates to dealer to perform a MEC reset for wireless projection issues
• 11024446Oct 8, 2025Other or unknown. This PI Addresses a possible solenoid wiring fault and how to inspect the build date to identify
• 11024439Oct 4, 2025Other or unknown. The Driver Information Center may display a message of Transport Mode On after the ignition is cycled.
• 11023091Sep 9, 2025Other or unknown. New Vehicle Monitoring Programs Section in IVH
• 11023145Sep 8, 2025Other or unknown. 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.
• 11022137Aug 22, 2025Other or unknown. 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.
• 11022085Aug 15, 2025Other or unknown. 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.
• 11022084Aug 14, 2025Other or unknown. This preliminary information advises a dealer on how to email GDS2 session logs into Technical Assistance.
• 11021792Aug 7, 2025Other or unknown. This Preliminary Information communication provides information to the technician about vehicles that have an intermittent no crank, no start, or start stall concern with the security light coming on. Technician may find Diagnostic Trouble Codes B3055, B3060, B3935, C0750, C0755, C0760, C0765, and/or C0775.
• 11021303Jul 28, 2025Other or unknown. 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.
• 11020863Jul 23, 2025Other or unknown. Customer Satisfaction Program. Certain model years and vehicle makes noted in the table above may have a condition where the battery is at risk for a drain following an over-the-air update. Dealers are to reprogram the serial data gateway module.
• 11020815Jul 23, 2025Other or unknown. Certain vehicles listed above, may have a condition where the transmission control valve has worn, resulting in a gradual loss of pressure within the valve. The effects can cause harsh shifting, setting a service engine soon message, reduced engine performance or P0747 diagnostic trouble code.
• 11020816Jul 18, 2025Other or unknown. This PI communicates the requirement to provide a pico file to receive diagnostic assistance from TAC.

← All problems reported for the 2021 Cadillac CT4