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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
PIC6536A2025-03-12. Service bulletin. STEERING; ENGINE. This Preliminary information communicates to the technicians some additional diagnostic steps to perform if they encounter a no crank condition and/or loss of power steering.
22-NA-0942025-03-12. Service bulletin. ENGINE; ELECTRICAL SYSTEM. This service bulletin provides repair information to correct a customer concern of a loss of cabin heat.
17-NA-0732025-03-12. Service bulletin. UNKNOWN OR OTHER. This warranty administration bulletin provides information regarding the field action courtesy transportation policy.
N2324127112025-03-11. Service campaign. UNKNOWN OR OTHER. Emissions Recall - General Motors has decided to conduct an Emission Recall involving certain 2021 Cadillac CT4 and CT5 vehicles with a 2.0L engine. The Engine Control Module (ECM) may not properly diagnose, may not set Diagnostic Trouble Codes (DTCs) or may not illuminate the Malfunction Indicator Light (Check Engine Light) if certain fault conditions of the catalytic converter were to occur. General Motors will update the software in the vehicles’ Engine Control Module (ECM) to correct the condition. If available, owners who have accepted applicable terms and conditions will have the opportunity to accept these software changes using wireless over-the-air (OTA) technology without having to bring their vehicle to a dealership. Alternatively, owners may have their vehicle serviced at a GM dealer to receive these software updates.
05-03-07-009L2025-03-08. Service bulletin. SUSPENSION; WHEELS. This service bulletin provides information on Wheel Alignment Specifications, Requirements and Recommendations for GM Vehicles.
11-00-89-005Y2025-03-08. Service bulletin. UNKNOWN OR OTHER. This Warranty Administration bulletin provides information on Dealer Empowerment for Goodwill, Customer Enthusiasm and Policy (U.S. Only).
05-08-51-001L2025-03-08. Service bulletin. STRUCTURE:BODY. This informational bulletin provides a procedure on how to remove the paint stain that may present itself under the shipping film.
N2424806312025-03-07. Service campaign. POWER TRAIN. 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. This special coverage covers vehicles that return after TCM Update Product Safety N242480630 and have P0747 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 March 6, 2025, 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 March 6, 2025, 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 install a new control valve body. The repairs will be made at no charge to the customer.
PIP5841E2025-03-02. Service bulletin. ENGINE. This Preliminary information communicates the potential for condensation to freeze up inside the Crankcase Pressure Sensor causing dtc P04FB to set.
PIP5966A2025-03-02. Service bulletin. POWER TRAIN. This Preliminary information communicates Diagnostic aids for a no start or DTC'S following a transmission replacement
PIP5966A2025-03-02. Service bulletin. POWER TRAIN. This Preliminary information communicates Diagnostic aids for a no start or DTC'S following a transmission replacement
16-NA-1092025-02-28. Service bulletin. STEERING. This service bulletin provides a procedure inspecting for excess grease or Sealant on the Exterior of the steering gear due to seeing grease or sealant on certain locations on the gear.
24-NA-2642025-02-27. Service bulletin. POWER TRAIN. This bulletin helps aid the tech in possible noise that may be normal or abnormal depending on the concern noted.
07-00-89-037V2025-02-27. Service bulletin. UNKNOWN OR OTHER. This warranty administration bulletin provides policy information for GM courtesy transportation and roadside assistance programs.
PIP5358D2025-02-25. Service bulletin. UNKNOWN OR OTHER. This Preliminary Information communication provides information to the technician about vehicles that have an unusual noise and is difficult to identify, isolate or pinpoint. Technician should get record a sound clip or take a video of the noise for assessment by engineering. Technician will need to call General Motors Technical Assistance Center for further assistance.
PIT5551Q2025-02-25. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates a "Forward Collision System Reduced" message displayed on the DIC when the Forward Automatic Braking has been set to the "Alert" setting. This is normal when the FAB has been set to "Alert".
16-NA-0192025-02-19. Service bulletin. POWER TRAIN. This service bulletin provides information on Transmission Adaptive Functions and Correcting Low Mileage Harsh Shifts, Slips, or Flares.
23-NA-0642025-02-12. Service bulletin. ELECTRICAL SYSTEM; UNKNOWN OR OTHER. This service bulletin provides information on the Transport Mode Feature, also known as Logistics mode, which is used to increase the 12V Battery stand time of the vehicle during transit and or long period of stand time at the dealerships.
22-NA-2442025-02-12. Service bulletin. UNKNOWN OR OTHER; STRUCTURE:BODY. This warranty administration service bulletin provides information about GM Accessories - Dealer-Installed, Repaired or Replaced During Warranty Coverage Period.
22-NA-0742025-02-12. Service bulletin. ENGINE. This service bulletin provides service information to technicians on guidelines to replace Oil Cooler, Oil Cooler Lines and Oil Tank if the engine was replaced where large amounts of debris has flowed throughout the oiling system.
21-NA-0432025-02-12. Service bulletin. VISIBILITY/WIPER; SERVICE BRAKES; ENGINE; ELECTRICAL SYSTEM; WHEELS. This bulletin advises the dealers to maintain the vehicle stock on hand by doing a full inspection on the vehicles before being sold (prepping) to the customer.
21-NA-1352025-02-12. Service bulletin. UNKNOWN OR OTHER; ELECTRICAL SYSTEM. This service bulletin provides information to inform dealership personnel about Law Enforcement and Government vehicles that request to disable or enable content.
10-08-110-001L2025-02-11. Service bulletin. STRUCTURE:BODY; VEHICLE SPEED CONTROL. This service bulletin provides information on proper use of floor mats.
01-08-42-001Q2025-02-11. Service bulletin. EXTERIOR LIGHTING. This service bulletin provides information on Exterior Lamp Condensation and Water Leak Information and Replacement Guidelines.
PIT5832U2025-02-03. Service bulletin. UNKNOWN OR OTHER. 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.