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Service bulletin 20NA178

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.

The communication, as NHTSA indexes it (as of 2026-10-19)
TypeService bulletin
NHTSA id10181705
Published by NHTSA2020-10-26
Manufacturer's number20NA178
Manufacturer's date2020-09-09
NHTSA componentSTEERING; ELECTRICAL SYSTEM

NHTSA's summary

This technical 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.

The document

The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.

Components

Electrical system, Steering

Vehicles listed
CADILLAC CT42020, 2021
CADILLAC CT52020, 2021
CHEVROLET SUBURBAN2021
CHEVROLET TAHOE2021
GMC YUKON2021
GMC YUKON XL2021

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Recalls for the same vehicles and component
20213802021-06-17. Steering
21V4550002021-06-17. STEERING:STEERING CONTROL MODULE
21V4210002021-06-10. AIR BAGS:SRS MALFUNCTION WARNING LAMP/LIGHT; ELECTRICAL SYSTEM:SOFTWARE

A recall listed here may apply to some of the same vehicles. Only the manufacturer can say whether it applies to one vehicle.

Other bulletins for the same vehicles and component
23-NA-1702025-10-25. Service bulletin. This bulletin advises the tech to inspect deeper into what may be to main cause of an engine failure.
PI0281L2025-06-12. Service bulletin. This preliminary informational (PI) bulletin provides information to dealership personnel that may be helpful when addressing underbody component corrosion with customers.
21-NA-1662025-06-06. Service bulletin. This informational bulletin provides information on the turn signal stalk not cancelling and/or mis cancelling.
24-NA-2292025-06-03. Service bulletin. This bulletin provides a procedure on how to check for a battery drain utilizing the Picoscope and how to measure the load on the system that may be causing a drain.
25-NA-0872025-05-02. Service bulletin. This service bulletin provides information on the proper Reflective High Temperature Heat and/or Insulating Tape to use for certain repairs, such as Wiring Harness Repairs.
23-NA-1852025-04-28. Service bulletin. This service bulletin helps diagnose/reduce possible CCND issues on Transfer Cases - Service 4WD on DIC, Intermittent Failures, Noise Concerns, Driveline/Steering Vibration/Shudder, Intermittent DTCs/MIL Illuminated, Engagement/Disengagement/Ratcheting Concerns.
13-08-116-001K2025-04-25. Service bulletin. The intent of this service 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.
24-NA-0982025-04-24. Service bulletin. This service bulletin provides information for dealers/technicians on Service Programming System (SPS) Error Codes E4398, E4399, E4401, E4403, M4404, M4413, M6954, M6955, E4414, E4423, E4491, E4492, or E6961 and resolution information.
25-NA-0652025-04-24. Service bulletin. This informational bulletin instructs the tech when fuel/fluid is needed to be tested and where it can be sent for analysis.
15-06-03-001F2025-04-15. Service bulletin. This service bulletin provides information to diagnose batteries that have set for a long period of time and/or cold weather climates and testing those batteries.