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Service bulletins for the 2021 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.

813 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
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-0282022-06-06. Service bulletin. POWER TRAIN:DRIVELINE; 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.
21-NA-2812022-06-06. Service bulletin. POWER TRAIN:DRIVELINE:HYDRAULIC:MOTOR/PUMP; POWER TRAIN. This service bulletin provides diagnostic information for technicians in cases of an ETRS system fault or a no start condition - If the vehicle needs to be moved, it is recommended to use wheel dollies, tire skates or the NEW Manual Park Release tool DT-52910.
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.
PIP5677F2022-04-18. Service bulletin. POWER TRAIN. This Preliminary information communicates to the dealer technician that the 10L60 and the 10L80 transmissions part restriction has ended.
PIE0676A2022-04-06. Service bulletin. POWER TRAIN; ENGINE AND ENGINE COOLING. This engineering information (EI) closure ends the need for further information from the field in regards to Engine Coolant Reservoir Being Overfilled with Discolored Coolant, Shudder, Shake, Vibration, Harsh Shift, Delayed Shift and/or Slipping Transmission Performance.
PIC6048N2022-02-14. Service bulletin. ELECTRICAL SYSTEM; POWER TRAIN; STEERING; AIR BAGS; LANE DEPARTURE; BACK OVER PREVENTION. This Preliminary Information communicates to the technician that some customers may comment on the operation of their haptic seat during a Lane Keep Assist event. Lane Keep Assist works differently than Lane Departure Warning. The Lane Keep Assist icon is solid amber, Forward Camera Module is actively commanding a torque to Electronic Power Steering. This means that the driver should also feel some feedback from the steering wheel. No Chimes or haptic in the seat. Lane Keep Assist icon is flashing amber; Forward Camera Module is actively commanding torque to Electronic Power Steering. This will also be accompanied with Lane Departure Warning chimes and haptic in the seat feedback based on the setting chosen in the vehicle settings. This will take place when the vehicle has crossed lane marking by (40 cm) or (15.75 in).
21NA2812021-12-27. Service bulletin. POWER TRAIN. This service bulletin provides diagnostic information for technicians in cases of an ETRS system fault or a no start condition - If the vehicle needs to be moved, it is recommended to use wheel dollies, tire skates or the NEW Manual Park Release tool DT-52910.
PIC5650J2021-09-13. 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.
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.
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.
21NA1062021-05-24. Service bulletin. POWER TRAIN. This informational bulletin advises the technician to verify the TCM is asleep before trying to repair the transmission in order for all the codes to be re-set.
16NA3382021-05-24. Service bulletin. POWER TRAIN. 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.
PIP57992021-05-17. Service bulletin. STRUCTURE; POWER TRAIN. This Preliminary information communicates to the dealer technician to replace the transmission valve body on 2019-2021 10 speed transmissions to correct DTCs P2812 and P2814 setting if Service Information does not lead to root case of these DTCs.
20NA1382021-05-03. Service bulletin. ENGINE AND ENGINE COOLING; POWER TRAIN. 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.
PIP5712B2021-04-19. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:CRANK/CAMSHAFT POSITION SENSOR; POWER TRAIN. This Preliminary information communicates to the technician a service Diagnostic / Repair tip to avoid causing the crankshaft sprocket to disengage from the crankshaft during crankshaft balancer or cam drive system component related service procedures.
150089004C2021-03-08. Service bulletin. SUSPENSION:FRONT:MACPHERSON STRUT; SUSPENSION:FRONT:SHOCK ABSORBER; POWER TRAIN:AUTOMATIC TRANSMISSION:FLUID/LUBRICANT. 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.
16NA0192021-02-22. Service bulletin. POWER TRAIN. This informational 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.