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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

Only bulletins with component: Engine are shown. Show all

Bulletins, newest first
N2424411202024-06-05. Warranty extension. ENGINE. Special Coverage. Certain vehicles, equipped with a 2.0 gasoline engine (RPO LSY), may have a condition that could cause the evaporative emissions purge pump to fail. If this condition were to occur, the Malfunction Indicator Lamp (Check Engine Light) will illuminate, and a diagnostic trouble code will set. This special coverage covers the 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 June 5, 2024, 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 June 5, 2024, 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 replace the evaporative emissions purge pump as necessary. The repairs will be made at no charge to the customer.
15-00-89-004G2024-05-15. Service bulletin. ENGINE; SUSPENSION; POWER TRAIN. This service bulletin provides technicians with information to help identify the differences between what is considered a fluid leak, and what is considered fluid seepage.
PIP5863B2024-04-15. Service bulletin. EXTERIOR LIGHTING; ENGINE AND ENGINE COOLING; FUEL SYSTEM, GASOLINE. 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.
16-NA-3832024-03-19. Service bulletin. ENGINE AND ENGINE COOLING. This technical bulletin advises of a new fuel injection cleaner kit used for decarbonizing the intake valves to correct conditions of rough idle, Crank no start, extended crank or misfire, MIL with DTCs, and explains how Top Tier fuels should be used to reduce carbon build-up.
PIE07822024-03-07. Service bulletin. ENGINE AND ENGINE COOLING. This engineering information (EI Lite) is requesting technicians use the FPR App process in regard to finding coolant leaking around the Coolant Control Valve (CCV).
22-NA-0742024-02-29. Service bulletin. ENGINE AND ENGINE COOLING. 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.
19-NA-0442024-02-21. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL; FUEL SYSTEM, GASOLINE. This service bulletin provides information on the cold start control system in DI engines to reduce cold start emissions and improve fuel economy.
16-NA-2222024-02-21. Service bulletin. ENGINE AND ENGINE COOLING. This bulletin provides information on Engine Concerns that could result from lack of scheduled maintenance, improper service or aftermarket calibrations.
16-NA-3382024-02-17. 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.
23-NA-2142024-02-14. Service bulletin. ENGINE AND ENGINE COOLING. This service bulletin provides Information on Purge Pump Part Replacement and Purge pump Part Number Interchangeability.
PI1394B2024-02-02. Service bulletin. POWER TRAIN; ENGINE AND ENGINE COOLING. This PI bulletin advises the technician on the proper way to install the pistons in an engine.
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.
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.
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.
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.
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.
21-NA-2792023-10-14. Service bulletin. ENGINE AND ENGINE COOLING. This service bulletin provides a procedure to replace the starter if found the cause of the rattle noise.
17-NA-1572023-09-26. Service bulletin. ENGINE AND ENGINE COOLING. This service bulletin explains the difference in oil filters for gas engines with new oil pump control systems and the possibilities of what may happen using the incorrect filter.
23-NA-1532023-09-26. Service bulletin. ENGINE AND ENGINE COOLING; POWER TRAIN. The service bulletin advises the tech of a normal transmission shift condition and the delay in throttle response when the throttle plate is opened rapidly and advises the customer that it is normal for the delay.
PIP5628G2023-09-18. Service bulletin. ENGINE. This Preliminary information communicates information that will need to be provided to TAC to aid in diagnosing if a vehicle comes in with misfire and DTC Codes P0300 - P0308 and/or P050D
18-NA-0732023-09-15. 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.
23-NA-1412023-09-13. Service bulletin. ENGINE AND ENGINE COOLING. This informational bulletin advised the technician that the engine and related parts will be debited if found that the tech didn't properly prepare the engine block from dirt and debris in bolt holes or if found that the block was damaged by the tech.
16-NA-2222023-09-08. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING. This bulletin provides information on Engine Concerns that could result from lack of scheduled maintenance, improper service or aftermarket calibrations.
15-00-89-004F2023-09-08. Service bulletin. STEERING; SUSPENSION; ENGINE AND ENGINE COOLING; POWER TRAIN. This service bulletin provides technicians with updated information to help identify the differences between what is considered a fluid leak, and what is considered fluid seepage.

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