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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
23-NA-1092023-07-27. Service bulletin. ELECTRICAL SYSTEM; AIR BAGS. This service bulletin provides a procedure to correct a customer concern of Service Restraint System and/or Airbag Readiness Message Displayed - DTCs B15DF / B15E3.
21-NA-0262023-07-25. Service bulletin. EQUIPMENT. This service bulletin provides information for dealers/technicians on accessory all-weather floor liners and flat mats warped or misshapen.
17-NA-0662023-07-25. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION; POWER TRAIN. This service bulletin provides information for automatic transmission Oil Cooler Flush and flow test.
23-NA-1252023-07-25. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT. This service bulletin provides information for dealers/technicians on Over the Air (OTA) and In Market Enhancement (IME) FAQs.
23-NA-0552023-07-25. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. This service bulletin provides information on the EL-52800 Diagnostic & Charge Battery Station (DCBS) – FAQs.
PIP5843C2023-07-17. Service bulletin. EXTERIOR LIGHTING. 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.
PIT5966B2023-07-17. Service bulletin. EQUIPMENT:ELECTRICAL. This Preliminary information communicates an issue with an OTA pending message still displayed after an OTA event and how to reset/clear the message.
PIT4261J2023-07-17. Service bulletin. TIRES:SIDEWALL. This Preliminary Information communication provides information to the technician about vehicles with tire sidewall irregularities. This is a visual condition that will not affect durability, reliability or performance of the tires. Dealer should communicate to the customer that slight sidewall indentations are a common characteristic of radial tire construction.
99-08-51-001F2023-07-14. Service bulletin. STRUCTURE. This service bulletin provides information on Paintless Dent Repair Process.
23-NA-1092023-07-14. Service bulletin. ELECTRICAL SYSTEM; AIR BAGS; SEATS. This service bulletin provides a procedure to correct a customer concern of Service Restraint System and/or Airbag Readiness Message Displayed - DTCs B15DF / B15E3.
23-NA-0642023-07-14. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT. 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.
23-NA-0422023-07-14. Service bulletin. BACK OVER PREVENTION:SOFTWARE; EQUIPMENT; ELECTRICAL SYSTEM. This service bulletin provides repair information to update radio software to correct customer concerns of Software related issues.
13-08-116-001I2023-07-13. Service bulletin. ELECTRICAL SYSTEM. The intent of this service bulletin is to identify aftermarket ALDL or DLC interface devices as potential sources for causing multiple customer concerns that do not have other diagnostic methods to identify them.
01-06-01-011N2023-07-13. Service bulletin. ENGINE AND ENGINE COOLING. This service bulletin provides guidelines and diagnostic/repair information to technicians regarding vehicle engine oil consumption.
23-NA-0072023-07-11. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT:ELECTRICAL:INFOTAINMENT:VIDEO (TOUCH)SCREEN/MONITOR/UNIT; EQUIPMENT. This service bulletin provides repair information to correct a customer concern of Black Radio Display Screen (Triangle and Camera with Slash Through it) with DTCs B1A62 82 and 86 Setting Current in Video Processing Module (VPM).
22-NA-2322023-07-11. Service bulletin. POWER TRAIN; ENGINE AND ENGINE COOLING; ENGINE AND ENGINE COOLING:ENGINE:OIL/LUBRICATION:PUMP. This informational bulletin advises the technician of a possibly noise coming from the transmission oil pump.
21-NA-0612023-07-11. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; ELECTRICAL SYSTEM. This service bulletin provides information for dealers on Using EL-52545 When Diagnosing PEPs Transmitter Key Fobs.
N23-2408522023-06-28. Service bulletin. ELECTRICAL SYSTEM. (There may be future updates under this same release number.) Your Cadillac keeps getting better. This software update includes the following if your vehicle is equipped: Refinements: Updates made to the network connectivity to prevent unwanted interruption of emergency calls. Updates made to the Adaptive Cruise Control functionality for improved performance and smoother driving experience. Updates made to the overall vehicle software update process. Updates made to the Super Cruise driver assistance technology for enhanced lane changes, improved tunnel performance, and an overall upgraded driving experience. A variety of other minor software updates to make your driving and in-vehicle experience better. Better Never Stops™
16-NA-1582023-06-27. Service bulletin. EQUIPMENT. This service bulletin describes the U.S. Dealer Special Tool Loan Program process.
23-NA-1032023-06-21. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. This service bulletin provides information on submitting quality Photos of Various Vehicle Concerns to the GM Technical Assistance Center (TAC).
04-07-30-013E2023-06-19. Service bulletin. POWER TRAIN; ENGINE AND ENGINE COOLING. This service bulletin provides information to dealership personnel on automatic transmission shift and engine driveability concerns and/or MIL ON due to aftermarket oil bath air filter use.
02-00-89-002V2023-06-19. 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).
PIC5650K2023-06-13. Service bulletin. POWER TRAIN; ELECTRICAL SYSTEM:IGNITION. 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, and/or B3935. Technician should not replace any parts for this concern. If unable to duplicate the concern ask if the customer uses any Radio Frequency Identification Devices when the concern is present. Dealer should also direct their customers to the appropriate section in the Owner manuals that references that the device complies.
PIT5832H2023-06-13. Service bulletin. BACK OVER PREVENTION. This Preliminary information communicates a diagnostic tip on how to resolve a issue if the serial data authentication configuration did not complete correctly.
PIP59212023-06-13. Service bulletin. EQUIPMENT. This Preliminary information communicates the possibility of the Intake Cam Actuator cover plate screws backing out and making unwanted contact with the Cam Carrier.

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