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Service bulletin 20NA191

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 id10181716
Published by NHTSA2020-10-26
Manufacturer's number20NA191
Manufacturer's date2020-09-17
NHTSA componentELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING

NHTSA's summary

This technical bulletin provides repair information to correct a customer concern of Auto Start/Stop Disabled with Malfunction Indicator Lamp (MIL) Illuminated and DTC U0599 set.

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, Engine

Trouble codes named

U0599

Vehicles listed
CADILLAC CT42020
CADILLAC CT52020

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

Other bulletins for the same vehicles and component
00-06-01-026R2025-12-03. Service bulletin. This service bulletin provides information on replacing the intake manifold when the engine is replaced after severe internal engine damage.
23-NA-1532025-10-25. Service bulletin. The service bulletin advises the tech of a normal transmission shift condition and the delay in throttle response when the throttle plate is opened rapidly and advises the customer that it is normal for the delay.
15-NA-0102025-07-07. Service bulletin. This service bulletin provides information to dealership personnel for new vehicles with less than 1,000 miles that may not pass California smog inspection or smog inspection in other states.
25-NA-0372025-06-26. Service bulletin. This bulletin advises the tech that the Exhaust Roller Follower may be the issue with the engine Ticking noise, misfire or rough run and what to replace if found the cause.
21-NA-2402025-06-16. Service bulletin. This service bulletin provides diagnostic repair information to correct an oil leak in the engine.
25-NA-1002025-06-12. Service bulletin. This warranty administration bulletin provides policy information on vehicles outside of a California Emissions State who move to and register their vehicle in a California Emission State may be entitled to the 7 year, 70,000-mile Emission Select State Component Limited Warranty.
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.
25-NA-0762025-04-29. Service bulletin. This informational bulletin advises the technician that the gasket for the timing chain tensioner is not required.
25-NA-0522025-04-28. Service bulletin. This bulletin advises the technician to flush the cooling system multiple times if oil has been found in the cooling system and replace the parts that may be contaminated due to oil in system.