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
23-NA-2142023-12-15. Service bulletin. ENGINE AND ENGINE COOLING. This informational bulletin provides Information on Purge Pump Part Replacement and Purge Part Number Interchange.
20-NA-1322023-12-15. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT; ELECTRICAL SYSTEM. This warranty administration bulletin provides policy information on the requirements for 12V battery testing and warranty replacements.
N222371151-122023-12-13. Service bulletin. STEERING. Customer Satisfaction Program. Due to the industry-wide semiconductor shortage, the heat feature on the steering wheel is not functional on certain vehicles listed above, built beginning November 17, 2021. The affected vehicle owners should have been made aware of the condition at sale, and notified that once parts are available, they would be eligible for a no additional cost retrofit to enable the feature. Dealers are to replace the steering wheel assembly.
20-NA-0182023-12-09. 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).
23-NA-2062023-12-06. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT. This service bulletin provides information for dealers/technicians on History DTCs To Ignore / NO SES / NO Malfunction Indicator Lamps / NO Warning Messages.
N2324127122023-12-06. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM); ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING. Service Update - Certain vehicles with a 2.0L engine have an Engine Control Module (ECM) that 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. 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. Dealers are to reprogram the ECM.
PIP59432023-12-04. Service bulletin. EQUIPMENT:MECHANICAL:POWER TAKE-OFF (PTO); POWER TRAIN. This Preliminary Information communication advises the technician on diagnostic aids to help with the diagnosis and repair of 8 Speed Transmissions
PIT5966C2023-12-04. Service bulletin. COMMUNICATION:MANUFACTURER TELEMATICS. This Preliminary information communicates an issue with an OTA pending message still displayed after an OTA event and how to reset/clear the message.
21-NA-1352023-11-29. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT; EXTERIOR LIGHTING; ELECTRICAL SYSTEM. This service bulletin provides information to inform dealership personnel about Law Enforcement and Government vehicles that request to disable or enable content.
17-NA-0872023-11-29. Service bulletin. WHEELS; STEERING; SUSPENSION. This service bulletin provides information on Characteristics of Wide Low Aspect Ratio Tires, Vehicle Pulls Left or Right, Wanders, Follows Depressions in Road Surface, Tramlining.
03-00-91-001I2023-11-22. Service bulletin. WHEELS; POWER TRAIN; STEERING; SUSPENSION; ENGINE AND ENGINE COOLING. This service bulletin provides a vibration analysis worksheet the technician can use in conjunction with the appropriate Vibration Analysis-Road testing procedure when diagnosing vibration concerns.
20-NA-1592023-11-15. Service bulletin. WHEELS. This Warranty Administration bulletin is for information on General Motors New Vehicle Tire Warranty Program (U.S. Dealers Only).
23-NA-1892023-11-15. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT. This service bulletin assists technicians in setting up PicoScope hardware/software to monitor CAN bus traffic (voltage patterns) to aid Technical Assistance (TAC) and Field Service Engineers (FSEs) in diagnosing electrical issues present on network communication circuits.
16-NA-3612023-11-10. Service bulletin. POWER TRAIN. This service bulletin provides service /diagnostic information to aid with a Transmission Harsh 1-2 Shift Upon First Start Up/Shift of the Day Under Light Throttle.
21-NA-2752023-11-06. Service bulletin. POWER TRAIN. This service bulletin provides repair information to correct customer concerns of Rear Wheel Lock Up, ABS Event, Loud Bang and a Flashing “D” on Driver Information Center (DIC) when Lightly or Moderately Accelerating Forcing an 8-7 or 8-6 Downshift.
17-NA-2392023-11-02. Service bulletin. SERVICE BRAKES, HYDRAULIC. This bulletin provides information on possible normal brake drag caused by the vehicle parked for an extended period of time.
13-03-10-001K2023-10-29. Service bulletin. EQUIPMENT; WHEELS. This service bulletin provides information on summer tire performance and tire cold weather cracking.
05-00-89-029F2023-10-29. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. This service bulletin provides information on General Motors Dealership Critical Equipment Requirements and Recommendations.
99-00-89-019Y2023-10-26. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. This Warranty Administration bulletin provides information on the Global Warranty Management (GWM) Warranty Parts Center (WPC) Parts Return Program.
17-NA-1702023-10-25. Service bulletin. WHEELS. This service bulletin provides information about the Hunter wheel Road Force balancers that should be utilized for all repairs requiring balance and Road Force measurement.
01-06-01-011O2023-10-25. Service bulletin. ENGINE AND ENGINE COOLING. This service bulletin provides guidelines and diagnostic/repair information to technicians regarding vehicle engine oil consumption.
20-NA-1592023-10-18. Service bulletin. TIRES; WHEELS. This Warranty Administration bulletin is for information on General Motors New Vehicle Tire Warranty Program (U.S. Dealers Only).
10-00-89-006J2023-10-18. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. This service bulletin provides information for dealers on how to submit a product information report (PIR) (Canada Only).
02-00-89-002W2023-10-18. 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. and Canada Dealers Only).
23-NA-1542023-10-16. Service bulletin. EQUIPMENT. This bulletin provides information on Warranty Administration – Required Operating Procedures - 8 Points (U.S. Only).

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