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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: Brakes are shown. Show all

Bulletins, newest first
25-NA-0652025-04-24. Service bulletin. STEERING; SERVICE BRAKES; FUEL/PROPULSION SYSTEM. This informational bulletin instructs the tech when fuel/fluid is needed to be tested and where it can be sent for analysis.
21-NA-0432025-02-12. Service bulletin. VISIBILITY/WIPER; SERVICE BRAKES; ENGINE; ELECTRICAL SYSTEM; WHEELS. This bulletin advises the dealers to maintain the vehicle stock on hand by doing a full inspection on the vehicles before being sold (prepping) to the customer.
21-NA-0432024-12-10. Service bulletin. STRUCTURE:BODY; WHEELS; ENGINE; SERVICE BRAKES; UNKNOWN OR OTHER. This bulletin advises the dealers to maintain the vehicle stock on hand by doing a full inspection on the vehicles before being sold (prepping) to the customer.
17-NA-2392024-11-14. Service bulletin. SERVICE BRAKES. This bulletin provides information on possible normal brake drag caused by the vehicle parked for an extended period of time.
21-NA-2752024-10-30. Service bulletin. WHEELS; SERVICE BRAKES; 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-2442024-05-30. Warranty extension. ELECTRICAL SYSTEM; EXTERIOR LIGHTING; STRUCTURE:BODY; UNKNOWN OR OTHER; SERVICE BRAKES. This service bulletin provides information about GM Accessories - Dealer-Installed, Repaired or Replaced During Warranty Coverage Period.
PIP5596A2024-04-15. Service bulletin. SERVICE BRAKES; FUEL SYSTEM, GASOLINE. This Preliminary information communicates that when removing the fuel line jumper hose care should be taken to be sure the line is reinstalled correctly to avoid a no/low fuel pressure situation.
17-NA-2392023-11-02. Service bulletin. SERVICE BRAKES, HYDRAULIC. This bulletin provides information on possible normal brake drag caused by the vehicle parked for an extended period of time.
PIC65162023-09-18. Service bulletin. PARKING BRAKE. This Preliminary information communicates diagnostic tips for Advanced Parking Assist being inop.
22-NA-2472023-05-04. Service bulletin. SERVICE BRAKES; ELECTRICAL SYSTEM. This service bulletin provides information to dealership personnel that after performing a brake inspection, brake pad replacement, or any other repair that requires the caliper piston to be reseated may be causing DTC C05B0 to falsely set for eBoost applications.
17-NA-2392023-02-23. Service bulletin. SERVICE BRAKES, HYDRAULIC. This bulletin provides information on possible normal brake drag caused by the vehicle parked for an extended period of time.
22-NA-2472022-12-24. Service bulletin. SERVICE BRAKES, HYDRAULIC. This service bulletin provides information to dealership personnel that after performing a brake inspection, brake pad replacement, or any other repair that requires the caliper piston to be reseated may be causing DTC C05B0 to falsely set for eBoost applications.
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.
PIT5569B2022-08-15. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT; SERVICE BRAKES, AIR:ANTILOCK:WHEEL SPEED SENSOR. This Preliminary information communicates direction and examples when diagnosing multiple DTCs, one of which includes U**** Byte 71 DTC.
21NA2752022-06-21. Service bulletin. WHEELS; SERVICE BRAKES. 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.
PIP5841A2022-06-13. Service bulletin. BACK OVER PREVENTION; SERVICE BRAKES. This Preliminary information communicates the potential for condensation to freeze up inside the Crankcase Pressure Sensor causing dtc P04FB to set.
070316004D2022-06-13. Service bulletin. SERVICE BRAKES. This service bulletin provides information for tire pressure monitoring (TPM) system concerns.
21-NA-0432022-06-02. Service bulletin. FUEL SYSTEM, GASOLINE; SERVICE BRAKES; ENGINE AND ENGINE COOLING; FUEL SYSTEM, DIESEL; WHEELS. This informational bulletin advises the dealers to maintain the vehicle stock on hand by doing a full inspection on the vehicles before being sold (prepping) to the customer.
18NA0672022-05-31. Service bulletin. SERVICE BRAKES. This service bulletin provides information for cleaning brake dust off of aluminum or chrome wheels.
PIP4723F2022-02-14. Service bulletin. SERVICE BRAKES, HYDRAULIC; FUEL SYSTEM, GASOLINE. This Preliminary Information communicates to the dealer the process for downloading or updating operating software for the Tire Pressure Monitor, Active Fuel Injector tester, multi media tester, PICO Scope, GR8 starting/charging tester and Vehicle Data Recorder tools, giving website address and step by step instructions to complete the update.
N2023205102021-02-16. Service bulletin. LANE DEPARTURE; FUEL SYSTEM, GASOLINE; SERVICE BRAKES, HYDRAULIC; ELECTRICAL SYSTEM; AIR BAGS; ENGINE AND ENGINE COOLING; POWER TRAIN. Customer Satisfaction Program. Certain vehicles, equipped with a gas engine, may have a condition in which the printed circuit board inside of the water pump may have been manufactured incorrectly potentially causing a water pump failure. The vehicle coolant system temperature is monitored and will display multiple warnings to the customer as coolant temperatures rise. At a set coolant temperature, the MIL will illuminate, DTC P2B85 will set in the engine control module (ECM), the oil pressure gauge will indicate high oil pressure and reduced torque with notification to the driver of reduced power will occur. If the customer continues to drive after this warning and the coolant temperature continues to rise, a chime will occur, the AC will be disabled and an additional message instructing the driver to idle will illuminate. If the customer continues to drive the vehicle after all previous warnings and the coolant temperature continues to rise a message the engine will shut down could occur, and the engine will be shut down. Dealers are to replace the water pump.

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