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
| PIP5632E | 2021-09-13. 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. |
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| PIC6384H | 2021-09-13. 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. |
| PIC6442 | 2021-09-13. Service bulletin. ELECTRICAL SYSTEM:PROPULSION SYSTEM:TRACTION BATTERY THERMAL:MANAGEMENT:SOFTWARE. This Preliminary information communicates that a condition exits that can cause the Drivers Information Center to be blank on startup and Engineering is investigating the concern. |
| PIC5650J | 2021-09-13. Service bulletin. POWER TRAIN; AIR BAGS. This Preliminary Information communication provides information to the technician about vehicles that have an intermittent no crank, no start, or start stall concern with the security light coming on. Technician may find Diagnostic Trouble Codes B3055, B3060, and/or B3935. Technician should not replace any parts for this concern. If unable to duplicate the concern ask if the customer uses any Radio Frequency Identification Devices when the concern is present. Dealer should also direct their customers to the appropriate section in the Owner manuals that references that the device complies. |
| PIT5698B | 2021-09-13. Service bulletin. ELECTRICAL SYSTEM:ADAS:BLINDSPOT:SENSORS. This Preliminary information communicates additional information on how a LIN bus operates and diagnostic tips when working on a LIN bus. |
| PIE0643 | 2021-08-09. Service bulletin. ELECTRICAL SYSTEM; ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL. This engineering information (EI) is requesting information from technicians to perform the check list provided and contact the engineer listed in regards to the Malfunction Indicator Lamp (MIL) illuminated on Driver Information Center (DIC). |
| 990420002L | 2021-08-09. 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. |
| 110089002E | 2021-08-09. Service bulletin. EQUIPMENT; EQUIPMENT ADAPTIVE/MOBILITY. This service bulletin provides information on GM Accessories ? Dealer-Installed, Repaired or Replaced During Warranty Coverage Period. |
| 080730035E | 2021-08-09. Service bulletin. EQUIPMENT; EQUIPMENT ADAPTIVE/MOBILITY; POWER TRAIN. This bulletin provides information on the harmful effects of water or ethylene glycol in transmission fluid. |
| 010842001N | 2021-08-09. 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. |
| 21NA152 | 2021-08-09. Service bulletin. VISIBILITY:GLASS, SIDE/REAR; EQUIPMENT. This service bulletin provides information for dealers/technicians on glass ultraviolet (UV) Ray protection and tint percentage. |
| 21NA137 | 2021-08-09. Service bulletin. EXTERIOR LIGHTING:HEADLIGHTS. This service bulletin provides information for dealers/technicians on headlamp beam shadow appearance, and/or driver side to passenger side beam appears unlevel. |
| 21NA135 | 2021-08-09. Service bulletin. COMMUNICATION: VEHICLE TO INFRASTRUCTURE. This service bulletin provides information to inform dealership personnel about Law Enforcement and Government vehicles that request to disable or enable content. |
| 21NA131 | 2021-08-09. Service bulletin. SEATS:FRONT ASSEMBLY:POWER ADJUST; ELECTRICAL SYSTEM. This service bulletin provides repair information to correct a customer concern of Memory Seat Module Does Not Adjust. |
| PIE0632 | 2021-08-09. 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. |
| PIE0614A | 2021-08-09. Service bulletin. SUSPENSION. This engineering information (EI) closure ends the need for further information from the field in regards to a popping and/or thump type noise heard from the front suspension during sharp turns and/or while backing out. |
| 130310001H | 2021-08-09. Service bulletin. TIRES. This service bulletin provides information on summer tire performance and tire cold weather cracking. |
| 100089006H | 2021-08-09. Service bulletin. EQUIPMENT. This service bulletin provides information for dealers on how to submit a product information report (PIR) (Canada Only). |
| 070089037Q | 2021-08-09. Service bulletin. EQUIPMENT. This warranty administration bulletin provides policy information for GM courtesy transportation and roadside assistance programs. |
| 070089037P | 2021-08-09. Service bulletin. EQUIPMENT. This warranty administration bulletin provides policy information for GM courtesy transportation and roadside assistance programs. |
| 21NA130 | 2021-07-19. Service bulletin. EXTERIOR LIGHTING. 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 | 2021-07-19. Service bulletin. FUEL SYSTEM, GASOLINE:STORAGE:EVAPORATIVE EMISSIONS:CANISTER. 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 | 2021-07-19. Service bulletin. ELECTRONIC STABILITY CONTROL:AUTOMATIC (ASC). 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 | 2021-07-19. 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 | 2021-07-19. Service bulletin. ELECTRICAL SYSTEM. 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. |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.