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Service bulletin 18NA379

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 id10183163
Published by NHTSA2020-11-30
Manufacturer's number18NA379
Manufacturer's date2020-10-12
NHTSA componentPOWER TRAIN:AUTOMATIC TRANSMISSION; ENGINE

NHTSA's summary

This technical bulletin provides a procedure to program the TCM to correct the customers concern of a MIL Illuminated, Vehicle wont go above 25 mph and/or 1-2 Shifts feel like a momentary tie up.

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

Engine, Transmission and driveline, Automatic transmission

Vehicles listed
BUICK ENCLAVE2019
CADILLAC XT42019
CHEVROLET TRAVERSE2019
GMC TERRAIN2019

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

Recalls for the same vehicles and component
20V6680002020-10-29. POWER TRAIN:AUTOMATIC TRANSMISSION

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
17-NA-0662023-07-25. Service bulletin. This service bulletin provides information for automatic transmission Oil Cooler Flush and flow test.
PIP5621C2022-10-17. Service bulletin. This Preliminary information communicates to the dealer technician that TAC recommends the utilization of the GDS2 software to aid in diagnosing automatic transmission concerns. TAC is requesting the GDS2 session logs be sent in before the dealer contacts TAC.
22-NA-1072022-06-04. Service bulletin. This service bulletin provides repair information to correct a customer concern of a Service AWD Message in DIC at Ignition On with DTC C056D Set.
990420002L2021-08-09. Service bulletin. This service bulletin provides information on Driveline Clunk Noise and what is acceptable and what is considered normal operation.
150089004C2021-03-08. Service bulletin. 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.
060089031F2020-12-21. Service bulletin. This service bulletin provides information on OEM and Remanufactured Engine and Automatic Transmission/Transaxle Identification.
1308116001F2020-12-07. Service bulletin. 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.
PIP5608D2020-08-10. Service bulletin. This Preliminary information communicates to perform a transmission fluid drain and fill to correct a TCC shudder concern.
17NA1062020-03-30. Service bulletin. This technical bulletin provides repair information to correct a customer concern of an interior boom noise heard while driving low speeds in high gear.
19NA2062020-03-02. Service bulletin. This technical bulletin provides repair information to correct a customer concern of seeing an intermittent Shift to Park message displayed while vehicle is in park.