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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
18-NA-2792024-08-14. Service bulletin. UNKNOWN OR OTHER; ELECTRICAL SYSTEM. This service bulletin provides information for dealers/technicians on the process to disable and enable passive unlocking.
PIT5832P2024-08-14. Service bulletin. UNKNOWN OR OTHER; ELECTRICAL SYSTEM. This Preliminary information communicates a diagnostic tip on how to resolve a issue if the serial data authentication configuration did not complete correctly.
PIP5865C2024-08-13. Service bulletin. FUEL/PROPULSION SYSTEM. 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.
PIT61802024-08-13. Service bulletin. SEATS. This Preliminary information communicates assistance in locating the Rear seat belt comfort guides in the parts catalog.
PIT5832N2024-08-13. 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.
PIT5832M2024-08-13. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates a diagnostic tip on how to resolve a issue if the serial data authentication configuration did not complete correctly.
PIP5569B2024-08-13. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates to the dealer an issue where the vehicle's engine may crank over unprompted and not start afterward. This is the result of hooking up the Active Fuel Injector Tool incorrectly on vehicles equipped with a direct fuel injection system. This Preliminary information instructs the dealer of a repair kit they received that will prevent this issue when installed correctly.
12-01-37-001G2024-08-13. Service bulletin. ENGINE; ELECTRICAL SYSTEM. This service bulletin provides information to dealership personnel on a new refrigerant (R1234yf) for A/C service.
PIC65512024-08-13. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates to dealer to perform a MEC reset for wireless projection issues
00-03-10-002M2024-08-13. Service bulletin. WHEELS. This service bulletin provides information on Chemical Staining, Pitting, Corrosion and/or Spotted Appearance of Chromed Aluminum Wheels.
16-NA-1582024-08-13. Service bulletin. UNKNOWN OR OTHER. This service bulletin describes the U.S. Dealer Special Tool Loan Program process.
17-NA-1572024-07-30. Service bulletin. ENGINE. 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.
99-04-20-002O2024-07-30. Service bulletin. POWER TRAIN. This service bulletin provides information on Driveline Clunk Noise and what is acceptable and what is considered normal operation.
16-NA-0192024-07-23. Service bulletin. POWER TRAIN. This service bulletin provides information on Transmission Adaptive Functions and Correcting Low Mileage Harsh Shifts, Slips, or Flares.
24-NA-1232024-07-18. Service bulletin. ENGINE. This service bulletin advises the technician that the purge pump part number has changed and limited supply.
16-NA-3832024-07-16. Service bulletin. ENGINE; FUEL/PROPULSION SYSTEM. This service 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.
04-06-04-051I2024-07-16. Service bulletin. FUEL/PROPULSION SYSTEM. This service bulletin provides information for maintenance cleaning of the fuel injectors and gasoline detergent additive.
22-NA-0702024-07-12. Service bulletin. UNKNOWN OR OTHER. This service bulletin provides information for replacement parts traceability (RPT) process to aid in tracking part replacements.
22-NA-0182024-07-12. Service bulletin. UNKNOWN OR OTHER. This service bulletin provides information for the Global Warranty Management (GWM) Warranty Parts Center (WPC) Part Photo Return Process (U.S. Dealers Only).
18-NA-0992024-07-12. Service bulletin. UNKNOWN OR OTHER. This bulletin provides information for use on a Product Assistance Claim (PAC), which is formerly known as a Product Allegation Resolution (PAR) claim.
18-NA-1252024-06-28. Service bulletin. ENGINE; ELECTRICAL SYSTEM. This service bulletin provides information for engine oil life monitor operation calculation.
24-NA-0982024-06-25. Service bulletin. ELECTRICAL SYSTEM. This service bulletin provides information for dealers/technicians on Service Programming System (SPS) Error Codes E4398, E4399, E4401, E4403, M4404, M4413, M6954, M6955, E4414, E4423, E4491, E4492, or E6961 and resolution information.
21-NA-0682024-06-22. Service bulletin. UNKNOWN OR OTHER; ELECTRICAL SYSTEM. This warranty administration bulletin provides policy information requirements applicable to key fob replacement under the New Vehicle Limited Warranty or under a Replacement Parts Warranty on 2017-2022 and newer model year vehicles with RPO ATH and AVJ.
20-NA-0162024-06-22. Service bulletin. UNKNOWN OR OTHER. This Warranty Administration bulletin provides information on customer vehicles concern results in a manufacturer repurchase from the customer, GM depends on the dealership to host and administer the repurchase closing and intake of the returning vehicle.
24-NA-0902024-06-18. Service bulletin. FORWARD COLLISION AVOIDANCE: ADAPTIVE CRUISE CONTROL; ELECTRICAL SYSTEM. This technical bulletin provides repair information to correct a customer concern of SuperCruise Unavailable – No road Info: Road Expansion.

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