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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: Transmission and driveline are shown. Show all

Bulletins, newest first
PI0281J2023-05-04. Service bulletin. POWER TRAIN; STEERING; STRUCTURE; SUSPENSION; ENGINE AND ENGINE COOLING. This preliminary informational (PI) bulletin provides information to dealership personnel which may be helpful when addressing underbody component corrosion with customers.
08-07-30-035G2023-04-22. Service bulletin. POWER TRAIN. This bulletin provides information on the harmful effects of water or ethylene glycol in transmission fluid.
PIT5985A2023-04-17. Service bulletin. POWER TRAIN. This Preliminary information communicates diagnostic tips on how to resolve a issues with vehicles that will not power up after a can bus 2 issue, lightning strike, or a failed over the air update.
16-NA-0192023-04-13. Service bulletin. POWER TRAIN. This service bulletin provides information on Transmission Adaptive Functions and Correcting Low Mileage Harsh Shifts, Slips, or Flares.
PIT59852023-03-13. Service bulletin. POWER TRAIN. This Preliminary information communicates diagnostic tips on how to resolve a issues with vehicles that will not power up after a can bus 2 issue, lightning strike, or a failed over the air update.
99-04-20-002N2023-03-03. 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-3382023-01-05. Service bulletin. POWER TRAIN; ENGINE AND ENGINE COOLING. This Warranty Admin service bulletin provides guidelines for Dealers Not Required and for Dealers Required to Contact the PQC for engine or transmission assembly replacement and explains the PQC process, GWM Transaction submission, vehicle service record retention and proper handling of assembly returns for Canadian Dealers only.
22-NA-2462022-12-23. Service bulletin. POWER TRAIN. This service bulletin advises the technician that the possible cause may not be from a faulty clutch piston or extension housing and to perform testing on transmission for possible other issues, but it still may be possible on high mile vehicles that orifices in housing may have come dislodged, causing the same customer concern.
20-NA-1382022-12-06. Service bulletin. POWER TRAIN; ENGINE AND ENGINE COOLING. This bulletin provides information on Policies Applicable to All U.S. Dealers for Engine and Transmission Assembly Replacement Under Warranty, Policy or Customer Enthusiasm and information on Submission of Warranty Transaction in Global Warranty Management.
PIC6395C2022-11-21. Service bulletin. POWER TRAIN. This Preliminary information communicates a parts restriction is in place for the Automatic Transmission Control on 2020 Cadillac CT4, and CT5.
22-NA-0282022-11-02. Service bulletin. WHEELS; POWER TRAIN. This service bulletin provides a repair procedure to correct a customer concern of a Whining/Whirring, Whistle, Squeaking, Groaning/Growling Noise Coming from Front Wheel/Engine Area.
PIP5621C2022-10-17. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM); POWER TRAIN. This Preliminary information communicates to the dealer technician that TAC recommends the utilization of the GDS2 software to aid in diagnosing automatic transmission concerns. TAC is requesting the GDS2 session logs be sent in before the dealer contacts TAC.
PIP5640A2022-10-17. Service bulletin. POWER TRAIN. This Preliminary Information communication provides information to the technician to not remove the torque converter bolts and start the engine as this may cause damage to the torque converter of the crankshaft on vehicles equipped with an automatic transmission.
15-00-89-004E2022-10-11. Service bulletin. POWER TRAIN; SUSPENSION; ENGINE AND ENGINE COOLING; SERVICE BRAKES, HYDRAULIC; STEERING. This service bulletin provides technicians with updated information to help identify the differences between what is considered a fluid leak, and what is considered fluid seepage.
06-00-89-031H2022-10-11. Service bulletin. POWER TRAIN; ENGINE AND ENGINE COOLING. This service bulletin provides information on OEM and Remanufactured Engine and Automatic Transmission/Transaxle Identification.
22-NA-1842022-10-07. Service bulletin. POWER TRAIN. This informational bulletin advises the technician of possibly installing the incorrect 1-2-7-8-R clutch fluid passage seal and which seal should be used with measurements of the seal.
22-NA-1812022-09-19. Service bulletin. POWER TRAIN. This diagnostic tip advises the tech not to separate the flexplate from the torque convertor or damage my occur if the engine is started while diagnosing for noise from the engine or transmission.
22-NA-1762022-09-19. Service bulletin. POWER TRAIN; ENGINE AND ENGINE COOLING. This technical bulletin provides information on a possible bolt and guide pin that may be missing from the control valve which will need to be installed to correct the repair.
21-NA-2752022-09-07. Service bulletin. POWER TRAIN. This service bulletin provides repair information to correct customer concerns of Rear Wheel Lock Up, ABS Event, Loud Bang and a Flashing “D” on Driver Information Center (DIC) when Lightly or Moderately Accelerating Forcing an 8-7 or 8-6 Downshift.
22-NA-0912022-07-12. Service bulletin. POWER TRAIN. This service bulletin provides repair procedure information to correct a customer concern of a Rear Axle Moan Type Noise During Left or Right Turns.
PIE06762022-06-13. Service bulletin. POWER TRAIN; ENGINE AND ENGINE COOLING. This engineering information (EI) is requesting information from technicians to perform the check list provided and contact the engineer listed in regards to Engine Coolant Reservoir Being Overfilled with Discolored Coolant, Shudder, Shake, Vibration, Harsh Shift, Delayed Shift and/or Slipping Transmission Performance.
22-NA-1072022-06-04. Service bulletin. ELECTRICAL SYSTEM; POWER TRAIN:AUTOMATIC TRANSMISSION. This service bulletin provides repair information to correct a customer concern of a Service AWD Message in DIC at Ignition On with DTC C056D Set.
21-NA-2752022-06-04. Service bulletin. POWER TRAIN. This service bulletin provides repair information to correct customer concerns of Rear Wheel Lock Up, ABS Event, Loud Bang and a Flashing “D” on Driver Information Center (DIC) when Lightly or Moderately Accelerating Forcing an 8-7 or 8-6 Downshift.
16NA3612022-05-31. Service bulletin. AIR BAGS; POWER TRAIN. This service bulletin provides service /diagnostic information to aid with a Transmission Harsh 1-2 Shift Upon First Start Up/Shift of the Day Under Light Throttle.
16-NA-0192022-05-10. Service bulletin. POWER TRAIN. This service bulletin provides information on Transmission Adaptive Functions and Correcting Low Mileage Harsh Shifts, Slips, or Flares.

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