WenmarOpen by Wenmar Pro

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
21-NA-2812024-04-05. 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.
22-NA-0282024-03-19. Service bulletin. 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.
PIP59682024-03-18. Service bulletin. POWER TRAIN. This Preliminary information communicates to have the dealer contact TAC with the transmission TUN number prior to transmission installation.
PIP59662024-03-18. Service bulletin. POWER TRAIN. This Preliminary information communicates Diagnostic aids for a no start or DTC'S following a transmission replacement
16-NA-3382024-02-17. 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.
PIP5841D2024-02-12. Service bulletin. POWER TRAIN. This Preliminary information communicates the potential for condensation to freeze up inside the Crankcase Pressure Sensor causing dtc P04FB to set.
22-NA-2462024-02-06. 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 other possible issues, but it still may be possible on high mileage vehicles that orifices in housing may have come dislodged, causing the same customer concern.
PI1394B2024-02-02. Service bulletin. POWER TRAIN; ENGINE AND ENGINE COOLING. This PI bulletin advises the technician on the proper way to install the pistons in an engine.
16-NA-3612024-01-13. Service bulletin. POWER TRAIN; EQUIPMENT. 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.
PIT5985C2023-12-18. 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.
PIT5832K2023-12-18. Service bulletin. POWER TRAIN. This Preliminary information communicates a diagnostic tip on how to resolve a issue if the serial data authentication configuration did not complete correctly.
PIP59432023-12-04. Service bulletin. EQUIPMENT:MECHANICAL:POWER TAKE-OFF (PTO); POWER TRAIN. This Preliminary Information communication advises the technician on diagnostic aids to help with the diagnosis and repair of 8 Speed Transmissions
03-00-91-001I2023-11-22. Service bulletin. WHEELS; POWER TRAIN; STEERING; SUSPENSION; ENGINE AND ENGINE COOLING. This service bulletin provides a vibration analysis worksheet the technician can use in conjunction with the appropriate Vibration Analysis-Road testing procedure when diagnosing vibration concerns.
16-NA-3612023-11-10. Service bulletin. 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.
21-NA-2752023-11-06. 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.
23-NA-1532023-09-26. Service bulletin. ENGINE AND ENGINE COOLING; POWER TRAIN. The service bulletin advises the tech of a normal transmission shift condition and the delay in throttle response when the throttle plate is opened rapidly and advises the customer that it is normal for the delay.
PIT5985B2023-09-18. 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.
PIP5621D2023-09-18. Service bulletin. 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.
15-00-89-004F2023-09-08. Service bulletin. STEERING; SUSPENSION; ENGINE AND ENGINE COOLING; POWER TRAIN. 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.
22-NA-2322023-08-03. Service bulletin. POWER TRAIN. This informational bulletin advises the technician of a possibly noise coming from the transmission oil pump.
17-NA-0662023-07-25. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION; POWER TRAIN. This service bulletin provides information for automatic transmission Oil Cooler Flush and flow test.
22-NA-2322023-07-11. Service bulletin. POWER TRAIN; ENGINE AND ENGINE COOLING; ENGINE AND ENGINE COOLING:ENGINE:OIL/LUBRICATION:PUMP. This informational bulletin advises the technician of a possibly noise coming from the transmission oil pump.
04-07-30-013E2023-06-19. Service bulletin. POWER TRAIN; ENGINE AND ENGINE COOLING. This service bulletin provides information to dealership personnel on automatic transmission shift and engine driveability concerns and/or MIL ON due to aftermarket oil bath air filter use.
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.
08-07-30-026H2023-06-06. Service bulletin. POWER TRAIN. This service bulletin provides information on some vehicles that may rock or move slightly forward or rearward while in Park at start up after cold soak. This condition may be accompanied by a clunk noise. This is a slight movement that is more often seen visually, rather than felt, when viewed from the outside and using the auto-start feature, if equipped.

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