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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: Electrical system are shown. Show all

Bulletins, newest first
20-NA-0182024-02-23. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT. This service bulletin provides information for dealers/technicians on MDI 2 Required When Programming Vehicles with Vehicle Intelligence Platform (VIP).
23-NA-1892024-02-14. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT. This service bulletin assists technicians in setting up PicoScope hardware/software to monitor CAN bus traffic (voltage patterns) to aid Technical Assistance (TAC) and Field Service Engineers (FSEs) in diagnosing electrical issues present on network communication circuits.
23-NA-0552024-02-14. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT. This service bulletin provides information on the EL-52800 Diagnostic & Charge Battery Station (DCBS) – FAQs.
PI0592I2024-02-02. Service bulletin. ELECTRICAL SYSTEM. This preliminary information (PI) provides information om Service Programming System (SPS) Error Codes (E4398, E4399, E4403, M4404, M4413, M6954, M6955, E4414, E4423, E4491 or E6961).
PIT5962A2024-01-29. Service bulletin. ELECTRICAL SYSTEM:HAND HEATER:WIRING HARNESS; UNKNOWN OR OTHER. This Preliminary information communicates a GM part number for reflective high temperature heat or insulating tape when repairing wiring harnesses.
PIT5851D2024-01-29. Service bulletin. ELECTRICAL SYSTEM:INSTRUMENT PANEL:SPEEDOMETER/ODOMETER. This Preliminary information communicates an issues with the odometer being incorrect after a programming event and how the dealership can resolve the issue.
PIT5698D2023-12-26. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates additional information on how a LIN bus operates and diagnostic tips when working on a LIN bus.
PIP5700E2023-12-18. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates to the dealer technician that the part numbers for the internal wiring harnesses for the 8 speed RWD transmissions are not listed in the Electronic Parts Catalog. Technicians are to refer to the information provided in this document to obtain the internal wiring harness part numbers by application.
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.
20-NA-0182023-12-09. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. This service bulletin provides information for dealers/technicians on MDI 2 Required When Programming Vehicles with Vehicle Intelligence Platform (VIP).
23-NA-2062023-12-06. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT. This service bulletin provides information for dealers/technicians on History DTCs To Ignore / NO SES / NO Malfunction Indicator Lamps / NO Warning Messages.
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.
23-NA-1892023-11-15. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT. This service bulletin assists technicians in setting up PicoScope hardware/software to monitor CAN bus traffic (voltage patterns) to aid Technical Assistance (TAC) and Field Service Engineers (FSEs) in diagnosing electrical issues present on network communication circuits.
07-08-49-020R2023-10-18. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT; ELECTRICAL SYSTEM:INSTRUMENT PANEL:SPEEDOMETER/ODOMETER. This informational bulletin provides information for the IPC odometer programming method quick reference guide.
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.
09-06-04-026X2023-08-03. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING. This bulletin provides information on identifying Non-GM Engine Calibrations for Gasoline Engines using the Tech 2 or GDS 2.
23-NA-1092023-07-27. Service bulletin. ELECTRICAL SYSTEM; AIR BAGS. This service bulletin provides a procedure to correct a customer concern of Service Restraint System and/or Airbag Readiness Message Displayed - DTCs B15DF / B15E3.
23-NA-1252023-07-25. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT. This service bulletin provides information for dealers/technicians on Over the Air (OTA) and In Market Enhancement (IME) FAQs.
23-NA-0552023-07-25. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. This service bulletin provides information on the EL-52800 Diagnostic & Charge Battery Station (DCBS) – FAQs.
23-NA-1092023-07-14. Service bulletin. ELECTRICAL SYSTEM; AIR BAGS; SEATS. This service bulletin provides a procedure to correct a customer concern of Service Restraint System and/or Airbag Readiness Message Displayed - DTCs B15DF / B15E3.
23-NA-0642023-07-14. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT. This service bulletin provides information on the Transport Mode Feature, also known as Logistics mode, which is used to increase the 12V Battery stand time of the vehicle during transit and or long period of stand time at the dealerships.
13-08-116-001I2023-07-13. Service bulletin. ELECTRICAL SYSTEM. The intent of this service bulletin is to identify aftermarket ALDL or DLC interface devices as potential sources for causing multiple customer concerns that do not have other diagnostic methods to identify them.
21-NA-0612023-07-11. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; ELECTRICAL SYSTEM. This service bulletin provides information for dealers on Using EL-52545 When Diagnosing PEPs Transmitter Key Fobs.
PIC5650K2023-06-13. Service bulletin. POWER TRAIN; ELECTRICAL SYSTEM:IGNITION. 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.
22-NA-2002023-05-06. Service bulletin. ELECTRICAL SYSTEM; LATCHES/LOCKS/LINKAGES. This service bulletin provides repair information to correct a customer concern of Child Safety Lock Update failure.

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