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
| PIC6048N | 2022-02-14. 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). |
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| 21NA257 | 2022-02-14. 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. |
| 21NA256 | 2022-02-14. 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. |
| N202313620 Messa | 2022-02-07. Service bulletin. EQUIPMENT. Service Update. V-Series vehicles removed from population. |
| N192282860 01 | 2022-02-07. Service bulletin. POWER TRAIN. Service Update. Certain vehicles may have a condition where the transmission enters a neutral state when the internal range sensor (IRS) fault is active. Dealers are to reprogram the transmission control module. |
| PIP5675G | 2022-01-24. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE; EQUIPMENT. This Preliminary information communicates to the dealer that a customer may comment that the MIL light is illuminated. The technician may find P1098 and/or P26BB set current or history. That this may be caused by a software anomaly, and that GM is currently looking into the issue. It provides testing and related direction based on the results. |
| PIP5628E | 2022-01-24. Service bulletin. ENGINE AND ENGINE COOLING. This Preliminary information communicates information that will need to be provided to TAC to aid in diagnosing if a vehicle comes in with misfire and DTC Codes P0300 - P0308 and/or P050D |
| 030310007K | 2022-01-03. Service bulletin. TIRES; WHEELS. This service bulletin provides information for dealers/technicians on Tire/Wheel Characteristics (Vibration, Balance, Shake, Flat Spotting) of GM Original Equipment Tires. |
| 030091001H | 2022-01-03. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY:VEHICLE CONTROLS:STEERING. 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. |
| 21NA279 | 2021-12-27. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. This service bulletin provides a procedure to replace the starter if found the cause of the rattle noise. |
| 21NA269 | 2021-12-27. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. This service bulletin provides repair information to correct a customer concern of Instrument Panel Cluster DIC Intermittent Blank Screen. |
| 21NA257 | 2021-12-27. Service bulletin. ENGINE AND ENGINE COOLING:COOLING SYSTEM; EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT. This service bulletin provides a service procedure to correct a customer concern of a Malfunction Indicator Lamp (MIL) Illuminated - DTC P3075 Set. |
| 21NA256 | 2021-12-27. Service bulletin. EXTERIOR LIGHTING; EQUIPMENT; VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM:ENGINE COOLANT HOSES AND FITTINGS. This service bulletin provides repair information for dealers/technicians to correct a customer concern of a Malfunction Indicator Lamp Illuminated with DTC P26BB Set. |
| 21NA244 | 2021-12-27. Service bulletin. EQUIPMENT; ENGINE; ELECTRICAL SYSTEM. This service bulletin provides a repair procedure to correct a customer concern of a No Fob detected message on Driver Information Center (DIC) and/or No Crank / No Start condition. |
| 21NA091 | 2021-12-27. Service bulletin. BACK OVER PREVENTION; EQUIPMENT. This service bulletin provides information for customers/dealers/technicians on Normal Rearview Camera Display Operation - Flashing Diamond - Spot - or UFO like image on Rear View Camera Display. |
| 20NA178 | 2021-12-27. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE; EQUIPMENT; STEERING. This service bulletin provides repair information to correct a customer concern of Service Driver Assist and/or Take Steering Messages on Start-up, Advanced Driver Assist Systems (ADAS) Features Not Available with DTCs U1614, U1615, U1616 Set. |
| 19NA104 | 2021-12-27. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT. This service bulletin provides information for dealers/technicians and customers on steam/vapor coming from the front grille or radiator area. |
| 20NA132 | 2021-12-20. Service bulletin. ELECTRICAL SYSTEM:12V/24V/48V BATTERY. This warranty administration bulletin provides policy information on the requirements for battery testing and warranty replacements. |
| 20NA114 | 2021-12-20. Service bulletin. ENGINE. This informational bulletin provides information for dealers/technicians on the false setting of DTC U0212. |
| 18NA073 | 2021-12-20. Service bulletin. ENGINE. This service bulletin provides graphics, information and guidelines for engine component wear to assist service personnel as a guideline to perform necessary engine repairs and prevent unnecessary engine replacement. |
| PIT5841A | 2021-10-25. Service bulletin. ENGINE AND ENGINE COOLING. This Preliminary information communicates information on a No Crank / No Start concern caused by a No Fob Detected message caused by an internal fault of the BCM. Dealer is to replace the BCM to correct this concern. |
| PIT5851 | 2021-10-25. Service bulletin. ELECTRICAL SYSTEM:INSTRUMENT PANEL:SPEEDOMETER/ODOMETER. This Preliminary information communicates an issues with the odometer being incorrect after a programming event and how the dealership can resolve the issue. |
| PIT3099U | 2021-09-13. Service bulletin. EQUIPMENT. This Preliminary Information communication provides information to the technician about installing General Motors Accessory parts/kits. Technicians should refer to Service Information for information regarding most accessories. Technicians may also contact PARTECH and/or the Techline Customer Support Center for additional support. |
| PIC6384G | 2021-09-13. Service bulletin. 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. |
| PIT4261G | 2021-09-13. Service bulletin. TIRES:SIDEWALL. This Preliminary Information communication provides information to the technician about vehicles with tire sidewall irregularities. This is a visual condition that will not affect durability, reliability or performance of the tires. Dealer should communicate to the customer that slight sidewall indentations are a common characteristic of radial tire construction. |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.