WenmarOpen by Wenmar Pro

Service bulletins for the 2020 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.

888 on file from NHTSA, as of 2026-10-19.

By type

By component

By trouble code

By topic

Only bulletins with component: Equipment and accessories are shown. Show all

Bulletins, newest first
21NA0912021-12-27. Service bulletin. BACK OVER PREVENTION; EQUIPMENT. This service bulletin provides information for customers/dealers/technicians on Normal Rearview Camera Display Operation - Flashing Diamond - Spot - or UFO like image on Rear View Camera Display.
20NA1782021-12-27. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE; EQUIPMENT; STEERING. This service bulletin provides repair information to correct a customer concern of Service Driver Assist and/or Take Steering Messages on Start-up, Advanced Driver Assist Systems (ADAS) Features Not Available with DTCs U1614, U1615, U1616 Set.
19NA1042021-12-27. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT. This service bulletin provides information for dealers/technicians and customers on steam/vapor coming from the front grille or radiator area.
PIT3099U2021-09-13. Service bulletin. EQUIPMENT. This Preliminary Information communication provides information to the technician about installing General Motors Accessory parts/kits. Technicians should refer to Service Information for information regarding most accessories. Technicians may also contact PARTECH and/or the Techline Customer Support Center for additional support.
PIP5632E2021-09-13. Service bulletin. EQUIPMENT:ELECTRICAL:ACCESSORY GENERATOR:CONTROLS. This Preliminary Information communication provides information to the technician that General Motors Technical Assistance Center may ask for Global Diagnostic System 2 Session Log. Technician will need use Global Diagnostic System 2 to send the session logs to General Motors Technical Assistance Center for further assistance on the vehicle in question.
990420002L2021-08-09. Service bulletin. POWER TRAIN:MANUAL TRANSMISSION; POWER TRAIN:AUTOMATIC TRANSMISSION; EQUIPMENT. This service bulletin provides information on Driveline Clunk Noise and what is acceptable and what is considered normal operation.
110089002E2021-08-09. Service bulletin. EQUIPMENT; EQUIPMENT ADAPTIVE/MOBILITY. This service bulletin provides information on GM Accessories ? Dealer-Installed, Repaired or Replaced During Warranty Coverage Period.
080730035E2021-08-09. Service bulletin. EQUIPMENT; EQUIPMENT ADAPTIVE/MOBILITY; POWER TRAIN. This bulletin provides information on the harmful effects of water or ethylene glycol in transmission fluid.
010842001N2021-08-09. Service bulletin. EXTERIOR LIGHTING; EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT. This service bulletin provides information for dealers/technicians on Exterior Lamp Condensation and Water Leaks and Replacement Guidelines.
21NA1522021-08-09. Service bulletin. VISIBILITY:GLASS, SIDE/REAR; EQUIPMENT. This service bulletin provides information for dealers/technicians on glass ultraviolet (UV) Ray protection and tint percentage.
PIE06322021-08-09. Service bulletin. EQUIPMENT. This engineering information (EI) requests dealership personnel involve GM Engineering in the event an Owner is in Receipt of a PAI (Proactive Alert Identifier) "SAC003" and/or the Dealer is informed of excessive Parasitic Drains on an in-inventory vehicle.
100089006H2021-08-09. Service bulletin. EQUIPMENT. This service bulletin provides information for dealers on how to submit a product information report (PIR) (Canada Only).
070089037Q2021-08-09. Service bulletin. EQUIPMENT. This warranty administration bulletin provides policy information for GM courtesy transportation and roadside assistance programs.
070089037P2021-08-09. Service bulletin. EQUIPMENT. This warranty administration bulletin provides policy information for GM courtesy transportation and roadside assistance programs.
20NA1592021-07-19. Service bulletin. EQUIPMENT. This Warranty Administration bulletin is for information on General Motors New Vehicle Tire Warranty Program (U.S. Dealers Only).
18NA3062021-07-19. Service bulletin. EQUIPMENT. This Warranty Administration bulletin provides information for dealers/Service advisors on when and how to submit a Pre-Repair Authorization (PRA).
21NA1172021-07-06. Service bulletin. EQUIPMENT. This service bulletin provides information and programming procedures for dealers/technicians on the release of Radio Software Update Version GB108.2 for vehicles equipped with Infotainment system RPO IOS or IOT, in addition to providing general robustness and stability enhancements.
18NA3062021-07-06. Service bulletin. EQUIPMENT. This Warranty Administration bulletin provides information for dealers/Service advisors on when and how to submit a Pre-Repair Authorization (PRA).
070089036J2021-06-07. Service bulletin. EQUIPMENT. This service bulletin provides information on Enhancing Field Product Reports with Digital Pictures.
020089002T2021-06-07. Service bulletin. EQUIPMENT. This service bulletin provides information for dealers/technicians on When and How to Submit a Field Product Report (FPR) (U.S. Dealers Only).
21NA1032021-05-24. Service bulletin. EQUIPMENT. This service bulletin provides information regarding Witness Marks from Panel Adjustments Made During Manufacturing and that it is considered a normal condition.
21NA0682021-05-24. Service bulletin. EQUIPMENT:ELECTRICAL. 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 (U.S. Only).
18NA1462021-05-24. Service bulletin. EQUIPMENT. This warranty administration bulletin provides policy information, proper labor operation selection and causal part identification for warranty transactions (U.S. Only).
18NA0732021-05-24. Service bulletin. EQUIPMENT. 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.
PIP5654A2021-05-17. Service bulletin. EQUIPMENT. This Preliminary information communicates to the dealer technician that the valve body Part Unique Number (PUN) may contain the letter O or the number 0.

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