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: Electrical system are shown. Show all
| 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. |
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| 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. |
| PIC6438B | 2021-09-13. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT. This Preliminary information communicates a condition where the Video Processing Control Module is not able to be programmed to the vehicle. This PI offeres a couple workarounds while Engineering evaluates the concern. |
| PIC6444 | 2021-09-13. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. This Preliminary information communicates a possible SIM issue with vehicles in the middle east. |
| PIC6438A | 2021-09-13. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates a condition where the Video Processing Control Module is not able to be programmed to the vehicle. This PI offeres a couple workarounds while Engineering evaluates the concern. |
| PIC6438 | 2021-09-13. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates a condition where the Video Processing Control Module is not able to be programmed to the vehicle. This PI offeres a couple workarounds while Engineering evaluates the concern. |
| PIT5698B | 2021-09-13. 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. |
| PIP5814 | 2021-09-13. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL; ELECTRICAL SYSTEM. This Preliminary information communicates that there some service parts released to dealers missing software. |
| N212332820 | 2021-08-09. Service bulletin. EQUIPMENT:APPLIANCE:TV/RADIO/SPEAKERS; EQUIPMENT:ELECTRICAL:RADIO/TAPE DECK/CD ETC.; ELECTRICAL SYSTEM:SOFTWARE. Service Update. Certain vehicles may not be able to access Apps. A most notable improvement list this software update may correct is located at the end of this bulletin for conditions or concerns a customer may experience. Dealers will reprogram the radio. |
| 21NA139 | 2021-08-09. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM). This service bulletin provides a repair procedure to correct a customer concern of a Malfunction Indicator Lamp (MIL) Illuminated - DTC P3055 Set. |
| 21NA127 | 2021-08-09. 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. |
| PIE0613A | 2021-08-09. Service bulletin. ELECTRICAL SYSTEM; ENGINE. This engineering information (EI) is requesting information from technicians to perform the check list provided and contact the engineer listed in regards to Check Engine Lamp illuminated on the Driver Information Center (DIC) and/or poor fuel fill. |
| 19NA044 | 2021-07-19. Service bulletin. ELECTRICAL SYSTEM; ENGINE. This service bulletin provides information on the cold start control system in DI engines to reduce cold start emissions and improve fuel economy. |
| 18NA279 | 2021-07-19. Service bulletin. LATCHES/LOCKS/LINKAGES; ELECTRICAL SYSTEM. This service bulletin provides information for dealers/technicians on the process to disable and enable passive unlocking. |
| 21NA124 | 2021-07-06. Service bulletin. ELECTRICAL SYSTEM. This service bulletin provides diagnostic tips/steps on testing for possible EVAP leaks in the system to correct a customer concern of an MIL Illuminated with DTCs P0442 and/or P0455 Set. |
| N202324050 | 2021-06-14. 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 |
| 21NA068 | 2021-05-10. Service bulletin. ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER. This warranty administration bulletin provides policy information requirements applicable to key fob replacement under the New Vehicle Limited Warranty or under a Replacement Parts Warranty on 2021 and newer model year vehicles with RPO ATH (U.S. Only). |
| 21NA061 | 2021-05-10. Service bulletin. ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER. This service bulletin provides information for dealers on Using EL-52545 When Diagnosing PEPs Transmitter Key Fobs (North America ONLY). |
| PIE0582B | 2021-05-03. Service bulletin. ELECTRICAL SYSTEM. This engineering informational bulletin is requesting information from technicians to perform the check list provided and contact the engineer listed in regards to the Head Up Display (HUD) being blank. |
| 20NA132 | 2021-05-03. Service bulletin. ELECTRICAL SYSTEM. This warranty administration bulletin provides policy information on the requirements for battery testing and warranty replacements. |
| 20NA237 | 2021-02-22. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE; EQUIPMENT:ELECTRICAL:RADIO/TAPE DECK/CD ETC.. This service bulletin provides V152 radio software update information to correct customer concerns of various software issues. |
| 20NA237 | 2021-02-01. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE; EQUIPMENT:ELECTRICAL:RADIO/TAPE DECK/CD ETC.; EQUIPMENT. This service bulletin provides V152 radio software update information to correct customer concerns of various software issues. |
| 16NA019 | 2021-02-01. Service bulletin. POWER TRAIN; ELECTRICAL SYSTEM:SOFTWARE. This informational bulletin provides information on Transmission Adaptive Functions and Correcting Low Mileage Harsh Shifts, Slips, or Flares. |
| PIE0582A | 2020-12-21. Service bulletin. EQUIPMENT; EQUIPMENT ADAPTIVE/MOBILITY; ELECTRICAL SYSTEM. This engineering informational bulletin is requesting information from technicians to perform the check list provided and contact the engineer listed in regards to the Head Up Display (HUD) being blank. |
| 1308116001F | 2020-12-07. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM; POWER TRAIN:AUTOMATIC TRANSMISSION. The intent of this technical bulletin is to identify aftermarket ALDL or DLC interface devices as potential sources for causing multiple customer concerns that do not have other diagnostic methods to identify them. |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.