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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

Bulletins, newest first
22-NA-0442022-04-08. Service bulletin. ELECTRICAL SYSTEM:BODY CONTROL MODULE/BCM. This service bulletin provides repair information to correct a customer concern of Check Engine MIL Illuminated in DIC Set by Body Control Module with DTC P0607.
01-00-89-010O2022-04-08. Service bulletin. UNKNOWN OR OTHER. This informational bulletin provides information on a guide to help reduce repeat visits for the same customer concern.
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.
22-NA-0742022-04-06. Service bulletin. ENGINE AND ENGINE COOLING. This service bulletin provides service information to technicians on guidelines to replace Oil Cooler, Oil Cooler Lines and Oil Tank if the engine was replaced where large amounts of debris has flowed throughout the oiling system.
22-NA-0702022-04-06. Service bulletin. EQUIPMENT. This service bulletin provides information for replacement parts traceability (RPT) process to aid in tracking part replacements.
22-NA-0092022-04-05. Service bulletin. ENGINE AND ENGINE COOLING. This service bulletin provides service information on new torque specification and installation procedure for ACDelco Spin-On Oil Filters.
18-NA-0992022-04-05. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. This bulletin provides information for use on a Product Assistance Claim (PAC), which is formerly known as a Product Allegation Resolution (PAR) claim.
17-NA-0522022-04-05. Service bulletin. WHEELS; EQUIPMENT. This bulletin updates the position of General Motors on refinishing fully color painted aluminum wheels with base paint. GM has established a new process for the way that refinishing under GM Warranty will be handled (U.S. ONLY).
04-06-04-051F2022-04-05. Service bulletin. FUEL SYSTEM, GASOLINE:FUEL INJECTION SYSTEM; EQUIPMENT:MECHANICAL. This service bulletin provides information for maintenance cleaning of the fuel injectors and gasoline detergent additive.
PIE0661B2022-04-02. Service bulletin. ELECTRICAL SYSTEM; FORWARD COLLISION AVOIDANCE. This engineering information (EI) is requesting information from technicians to perform the check list provided and contact the engineer listed in regards to a Forward Collision Icon Message Illuminated on Driver Information Center (DIC) and/or No DTCs Set.
13-03-10-001I2022-03-19. Service bulletin. SUSPENSION; WHEELS. This service bulletin provides information on summer tire performance and tire cold weather cracking.
PIC64502022-03-14. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates a process to correct the concern of Unable to contact OnStar after the 3G EOL on 2015-2022 model year vehicles in the United States.
PIT3271L2022-03-14. Service bulletin. WHEELS; TIRES. This Preliminary Information communication provides information to the technician about changing the tire and wheel size on vehicles. General Motors will only support a tire calibration for tires that have been sized, tested and designed for the vehicle in question and its applications. Technician should not use the information that is provided by the antilock braking system tire size selection.
PIT5762E2022-02-14. Service bulletin. COMMUNICATION: VEHICLE TO INFRASTRUCTURE. This Preliminary information communicates an issues with false codes setting in vehicles due to timing issues between the modules.
PIP5817B2022-02-14. Service bulletin. BACK OVER PREVENTION. This Preliminary information communicates to the dealers information related to a hot idle tick noise from the engine. Testing to isolate the noise to the upper engine / valve train and repair recommendations related to valve train components.
PIT5832A2022-02-14. Service bulletin. COMMUNICATION. This Preliminary information communicates a diagnostic tip on how to resolve a issue if the serial data authentication configuration did not complete correctly.
PIP5817A2022-02-14. Service bulletin. BACK OVER PREVENTION. This Preliminary information communicates to the dealers information related to a hot idle tick noise from the engine. Testing to isolate the noise to the upper engine / valve train and repair recommendations related to valve train components.
PIC6384H2022-02-14. Service bulletin. STRUCTURE; ELECTRICAL SYSTEM. This Preliminary information communicates a parts restriction is in place for the Body Control Module on 2020 Cadillac CT4, CT5, Chevrolet Corvette, Suburban, Tahoe and GMC Yukon.
PIP4902P2022-02-14. Service bulletin. COMMUNICATION:MANUFACTURER TELEMATICS. This Preliminary Information communication provides information to the technician that General Motors Technical Assistance Center may ask for Global Diagnostic System 2 Session Log. Technician will need use Global Diagnostic System 2 to send the session logs to General Motors Technical Assistance Center for further assistance on the vehicle in question.
PIP5632F2022-02-14. Service bulletin. ENGINE. This Preliminary Information communication provides information to the technician that General Motors Technical Assistance Center may ask for Global Diagnostic System 2 Session Log. Technician will need use Global Diagnostic System 2 to send the session logs to General Motors Technical Assistance Center for further assistance on the vehicle in question.
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.
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).
21NA2572022-02-14. Service bulletin. EXTERIOR LIGHTING; ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM). This service bulletin provides a service procedure to correct a customer concern of a Malfunction Indicator Lamp (MIL) Illuminated - DTC P3075 Set.
21NA2562022-02-14. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE; ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM); EXTERIOR LIGHTING. This service bulletin provides repair information for dealers/technicians to correct a customer concern of a Malfunction Indicator Lamp Illuminated with DTC P26BB Set.
N2123308302022-02-07. Service bulletin. EQUIPMENT:ELECTRICAL:NAVIGATIONAL SYSTEM(GLOBAL POSITIONING SYSTEM); EQUIPMENT; ELECTRICAL SYSTEM. Service Update. Certain vehicles may have had incorrect parameters set in the One Time Programable (OTP) Chip area to initialize GPS Navigation System correctly once installed or assembled into the vehicle during manufacturing of the center stack module (CSM). Dealers will reprogram the radio.

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