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
| N202319300 | 2021-03-22. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION. Customer Satisfaction Program - Certain vehicles, equipped with a 9-speed automatic transmission, may contain transmissions that could shift harshly. Dealers are to replace the transmission. |
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| N202321843 01 | 2021-03-22. Service bulletin. AIR BAGS; POWER TRAIN; EXTERIOR LIGHTING. Service Update. On certain vehicles equipped with automatic transmissions, the clutch spring retaining ring may not be fully seated. Vehicles with this condition may set DTC Code P0747 and the MIL light (malfunction indicator light) will illuminate. This typically occurs at low mileage. Dealers will inspect the transmission by following the procedure and if it fails, the transmission will be replaced. |
| 150089004C | 2021-03-08. Service bulletin. SUSPENSION:FRONT:MACPHERSON STRUT; SUSPENSION:FRONT:SHOCK ABSORBER; POWER TRAIN:AUTOMATIC TRANSMISSION:FLUID/LUBRICANT. 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. |
| 21NA026 | 2021-03-08. Service bulletin. EQUIPMENT; STRUCTURE; EQUIPMENT ADAPTIVE/MOBILITY. This service bulletin provides information for dealers/technicians on accessory all-weather floor liners and flat mats warped or misshapen. |
| 18NA073 | 2021-03-01. 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. |
| 090604026S | 2021-03-01. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:GASOLINE; EQUIPMENT. This bulletin provides information on identifying Non-GM Engine Calibrations for Gasoline Engines using the Tech 2 or GDS 2. |
| 040089015V | 2021-03-01. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. This bulletin provides information on Warranty Administration ? Required Operating Procedures - 8 Points (U.S. Only). |
| 010601011L | 2021-03-01. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:OIL/LUBRICATION; EQUIPMENT. This informational bulletin provides guidelines and diagnostic/repair information to technicians regarding vehicle engine oil consumption. |
| N202321920 | 2021-03-01. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; ENGINE AND ENGINE COOLING; EQUIPMENT. 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. |
| 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. |
| 20NA235 | 2021-02-22. Service bulletin. EQUIPMENT:APPLIANCE:TV/RADIO/SPEAKERS. This service bulletin provides information to aid a dealer/customer concern of Radio Unwanted Phantom Touch or Non-Responsive to Touch After Cleaning/Disinfecting Radio Display. |
| 20NA159 | 2021-02-22. Service bulletin. TIRES. This Warranty Administration bulletin is for information on General Motors New Vehicle Tire Warranty Program (U.S. Dealers Only). |
| 18NA306 | 2021-02-22. Service bulletin. EQUIPMENT. This Warranty Administration bulletin provides information for dealers/Service advisors on when and how to submit a Pre-Repair Authorization (PRA). |
| 16NA019 | 2021-02-22. Service bulletin. POWER TRAIN. This informational bulletin provides information on Transmission Adaptive Functions and Correcting Low Mileage Harsh Shifts, Slips, or Flares. |
| N202321920 | 2021-02-22. Service bulletin. ENGINE AND ENGINE COOLING. 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. |
| N202319300 | 2021-02-16. Service bulletin. POWER TRAIN. Customer Satisfaction Program - certain vehicles equipped with a 9-speed automatic transmission may contain transmissions that could shift harshly. These transmissions must be replaced before sale and delivery to a customer. Parts are currently not available, but when parts are available, dealers will replace the transmission. |
| N202321843 | 2021-02-16. Service bulletin. EXTERIOR LIGHTING; AIR BAGS. Service Update. On certain vehicles equipped with automatic transmissions, the clutch spring retaining ring may not be fully seated. Vehicles with this condition may set DTC Code P0747 and the MIL light (malfunction indicator light) will illuminate. This typically occurs at low mileage. Dealers are to perform the inspection procedure contained within this bulletin. |
| N202321920 | 2021-02-16. 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. |
| PIC6425A | 2021-02-16. 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. |
| PIC6425 | 2021-02-16. 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. |
| PIP5772 | 2021-02-16. Service bulletin. FUEL SYSTEM, GASOLINE. This Preliminary information communicates to the technicians to replace the CAC outlet hose if damaged. |
| 090604026S | 2021-02-01. Service bulletin. EQUIPMENT; EQUIPMENT ADAPTIVE/MOBILITY; ENGINE AND ENGINE COOLING. This bulletin provides information on identifying Non-GM Engine Calibrations for Gasoline Engines using the Tech 2 or GDS 2. |
| 040089015V | 2021-02-01. Service bulletin. EQUIPMENT. This bulletin provides information on Warranty Administration ? Required Operating Procedures - 8 Points (U.S. Only). |
| 010601011L | 2021-02-01. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT. This informational bulletin provides guidelines and diagnostic/repair information to technicians regarding vehicle engine oil consumption. |
| 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. |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.