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Service bulletins for the 2021 Cadillac XT4

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.

684 on file from NHTSA, as of 2026-10-19.

By type

By component

By trouble code

By topic

Only bulletins with component: Driver assistance are shown. Show all

Bulletins, newest first
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).
21NA0912021-12-27. 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.
PIT5698B2021-09-13. Service bulletin. ELECTRICAL SYSTEM:ADAS:BLINDSPOT:SENSORS. This Preliminary information communicates additional information on how a LIN bus operates and diagnostic tips when working on a LIN bus.
21NA1272021-08-09. Service bulletin. ELECTRICAL SYSTEM:ADAS:HUD:SOFTWARE; EQUIPMENT. This technical bulletin provides repair information to correct a customer concern of Head Up Display (HUD) Blank, Non-Responsive to Brightness, Aim, or Page Controls, DTC U1518 Set.
21NA0912021-07-19. Service bulletin. BACK OVER PREVENTION. 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.
21NA0912021-07-06. Service bulletin. BACK OVER PREVENTION. 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.
N2023240502021-06-14. Service bulletin. FUEL SYSTEM, GASOLINE; BACK OVER PREVENTION; FUEL SYSTEM, DIESEL; ELECTRICAL SYSTEM. Service Update Bulletin. Certain vehicles equipped with a 2.0L Diesel Engine, RPO (LSQ), may have a condition where the diesel particulate filter, (DPF), sensor indicates a high soot loading has occurred. This could potentially cause a diagnostic trouble code (DTC) P244B to set, resulting in reduced power. Engine Control Module Reprogramming with SPS
PIT5791A2021-04-19. Service bulletin. EQUIPMENT:ELECTRICAL:RADIO/TAPE DECK/CD ETC.; BACK OVER PREVENTION:SOFTWARE. This Preliminary information communicates a condition where the radio may display a :connection not availale, please call OnStar agent". This bulletin advises that Engineering is working on a software solution that will prevent the message from displaying when listening to non-SXM sources, but still allow the message to display when a loss of connectivity exists and the user is attempting to play Sirius XM.
PIC6425C2021-04-19. Service bulletin. BACK OVER PREVENTION:SOFTWARE. This Preliminary information communicates A list of software concerns and advises that engineering is working on a resolution. This PI will be changed to a bulletin once the Software is released.
N2023219202021-02-16. Service bulletin. ENGINE AND ENGINE COOLING; BACK OVER PREVENTION; AIR BAGS. Service Update. A small number of vehicles may have a coolant inlet pipe that may present an obstructed threaded hole for the coolant temp sensor which could result in the check engine light coming on or a potential coolant leak. Dealers are to replace the coolant inlet pipe and temperature sensor.
PIC6425A2021-02-16. Service bulletin. BACK OVER PREVENTION:SOFTWARE. This Preliminary information communicates A list of software concerns and advises that engineering is working on a resolution. This PI will be changed to a bulletin once the Software is released.
PIC64252021-02-16. Service bulletin. BACK OVER PREVENTION:SOFTWARE. This Preliminary information communicates A list of software concerns and advises that engineering is working on a resolution. This PI will be changed to a bulletin once the Software is released.
PIC6425A2021-01-25. Service bulletin. BACK OVER PREVENTION:SOFTWARE. This Preliminary information communicates A list of software concerns and advises that engineering is working on a resolution. This PI will be changed to a bulletin once the Software is released.
PIC64252021-01-25. Service bulletin. BACK OVER PREVENTION:SOFTWARE. This Preliminary information communicates A list of software concerns and advises that engineering is working on a resolution. This PI will be changed to a bulletin once the Software is released.
PIT5551F2020-11-16. Service bulletin. FORWARD COLLISION AVOIDANCE. This Preliminary information communicates a "Forward Collision System Reduced" message displayed on the DIC when the Forward Automatic Braking has been set to the "Alert" setting. This is normal when the FAB has been set to "Alert".

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