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
| 20NA159 | 2021-07-19. Service bulletin. EQUIPMENT. This Warranty Administration bulletin is for information on General Motors New Vehicle Tire Warranty Program (U.S. Dealers Only). |
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| 19NA044 | 2021-07-19. Service bulletin. ELECTRICAL SYSTEM; ENGINE. This service bulletin provides information on the cold start control system in DI engines to reduce cold start emissions and improve fuel economy. |
| 18NA306 | 2021-07-19. Service bulletin. EQUIPMENT. This Warranty Administration bulletin provides information for dealers/Service advisors on when and how to submit a Pre-Repair Authorization (PRA). |
| 18NA279 | 2021-07-19. Service bulletin. LATCHES/LOCKS/LINKAGES; ELECTRICAL SYSTEM. This service bulletin provides information for dealers/technicians on the process to disable and enable passive unlocking. |
| 17NA087 | 2021-07-19. Service bulletin. TIRES; SUSPENSION. This informational bulletin provides information on Characteristics of Wide Low Aspect Ratio Tires, Vehicle Pulls Left or Right, Wanders, Follows Depressions in Road Surface, Tramlining. |
| 21NA130 | 2021-07-06. Service bulletin. ENGINE AND ENGINE COOLING. This service bulletin provides a repair procedure to correct a customer concern of Malfunction Indicator Lamp (MIL) Illuminated, DTC P31E8, P31DB, P31D4 and/or P31E2 Set. |
| 21NA124 | 2021-07-06. Service bulletin. ELECTRICAL SYSTEM. This service bulletin provides diagnostic tips/steps on testing for possible EVAP leaks in the system to correct a customer concern of an MIL Illuminated with DTCs P0442 and/or P0455 Set. |
| 21NA117 | 2021-07-06. 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. |
| 21NA091 | 2021-07-06. Service bulletin. BACK OVER PREVENTION. 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. |
| 20NA178 | 2021-07-06. Service bulletin. 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. |
| 20NA159 | 2021-07-06. Service bulletin. TIRES. This Warranty Administration bulletin is for information on General Motors New Vehicle Tire Warranty Program (U.S. Dealers Only). |
| 19NA044 | 2021-07-06. Service bulletin. ENGINE AND ENGINE COOLING. This service bulletin provides information on the cold start control system in DI engines to reduce cold start emissions and improve fuel economy. |
| 18NA306 | 2021-07-06. Service bulletin. EQUIPMENT. This Warranty Administration bulletin provides information for dealers/Service advisors on when and how to submit a Pre-Repair Authorization (PRA). |
| 18NA279 | 2021-07-06. Service bulletin. LATCHES/LOCKS/LINKAGES. This service bulletin provides information for dealers/technicians on the process to disable and enable passive unlocking. |
| 17NA087 | 2021-07-06. Service bulletin. TIRES. This informational bulletin provides information on Characteristics of Wide Low Aspect Ratio Tires, Vehicle Pulls Left or Right, Wanders, Follows Depressions in Road Surface, Tramlining. |
| N212329521 | 2021-06-14. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL. Emission Recall. General Motors has decided to conduct a voluntary emissions recall involving certain vehicles. The Vehicle Emissions Control Information (VECI) label may not contain the correct On-Board Diagnostic (OBD) system identifier. Since a new label can be easily installed, and to reduce customer inconvenience, the label will be sent directly to customers of record along with the installation instructions. Customers may install the label or, if they desire, they may take the label to their dealer for installation at no charge. |
| N202307080 01 | 2021-06-14. Service bulletin. ELECTRICAL SYSTEM. Service Update Bulletin (Labor Codes Added). Certain vehicles may have a condition where the engine control module (ECM) software allows the Auto Stop to occur at a state of charge below 65%. Auto Stop is supposed to be inhibited at 65% to protect against excessive battery wear and discharge. Dealers are to reprogram the ECM. |
| PIC6392C | 2021-06-14. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates a parts restriction is in place for the Sensing and Diagnostic Module on 2020 Cadillac CT4, CT5 and Chevrolet Corvette. |
| PIC6384F | 2021-06-14. Service bulletin. ELECTRICAL SYSTEM; STRUCTURE. This Preliminary information communicates a parts restriction is in place for the Body Control Module on 2020 Cadillac CT4, CT5, Chevrolet Corvette, Suburban, Tahoe and GMC Yukon. |
| PIC6437 | 2021-06-14. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates the Radio may stay on after ignition off and door opened if there is an Over The Air update pending and to review SI document ID 5778263 for Over The Air update description and operation. |
| PIP5804 | 2021-06-14. Service bulletin. ENGINE AND ENGINE COOLING. This Preliminary information communicates the possibility of a inaccurate #1 Coolant Temperature Sensor causing the engine to run hot or overheat with possible over temperature message displayed on DIC |
| PIC6384E | 2021-06-14. Service bulletin. ELECTRICAL SYSTEM; STRUCTURE. This Preliminary information communicates a parts restriction is in place for the Body Control Module on 2020 Cadillac CT4, CT5, Chevrolet Corvette, Suburban, Tahoe and GMC Yukon. |
| 070089036J | 2021-06-07. Service bulletin. EQUIPMENT. This service bulletin provides information on Enhancing Field Product Reports with Digital Pictures. |
| 050308002I | 2021-06-07. Service bulletin. SUSPENSION. This service bulletin provides information to dealership personnel on diagnosis and replacement of shock absorber and strut due to fluid leak. |
| 020089002T | 2021-06-07. 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). |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.