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Service bulletin 19NA057

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 id10158849
Published by NHTSA2019-04-22
Manufacturer's number19NA057
Manufacturer's date2019-03-19
NHTSA componentPOWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM); ELECTRICAL SYSTEM:SOFTWARE; ENGINE; EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT

NHTSA's summary

This Technical bulletin provides a procedure for dealers/technicians to correct a condition of Malfunction Indicator Lamp (MIL) Illuminated, DTC P0420 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, Equipment and accessories, Transmission and driveline, Automatic transmission, Software, Transmission control module

Trouble codes named

P0420

Vehicles listed
BUICK ENCORE2013, 2014, 2015
CHEVROLET TRAX2013, 2014, 2015

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

Recalls for the same vehicles and component
16V5020002016-07-05. ELECTRICAL SYSTEM:IGNITION; POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM)
16V4220002016-06-10. ELECTRICAL SYSTEM:SOFTWARE; EQUIPMENT:ELECTRICAL:RADIO/TAPE DECK/CD ETC.
16V2570002016-04-28. ELECTRICAL SYSTEM:SOFTWARE; EQUIPMENT:ELECTRICAL:RADIO/TAPE DECK/CD ETC.

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
20-NA-1322024-04-05. Service bulletin. This warranty administration bulletin provides policy information on the requirements for 12V battery testing and warranty replacements.
1300890032023-12-11. Service bulletin. Vehicle Software Enhancements
17-NA-0662023-07-25. Service bulletin. This service bulletin provides information for automatic transmission Oil Cooler Flush and flow test.
PIP5632G2023-01-30. Service bulletin. This Preliminary Information communication provides information to the technician that General Motors Technical Assistance Center may ask for Global Diagnostic System 2 Session Log. Technician will need use Global Diagnostic System 2 to send the session logs to General Motors Technical Assistance Center for further assistance on the vehicle in question.
PIP4902Q2023-01-30. Service bulletin. This Preliminary Information communication provides information to the technician that General Motors Technical Assistance Center may ask for Global Diagnostic System 2 Session Log. Technician will need use Global Diagnostic System 2 to send the session logs to General Motors Technical Assistance Center for further assistance on the vehicle in question.
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.
06-00-89-031D2021-09-07. Service bulletin. OEM and Remanufactured Engine and Automatic Transmission/Transaxle Identification
990420002L2021-08-09. Service bulletin. This service bulletin provides information on Driveline Clunk Noise and what is acceptable and what is considered normal operation.
PI0928B2021-04-27. Service bulletin. Bump, Surge or Vibration at Idle in Drive at a Stop Condition/Concern Some customers may comment on a bump feeling, a surge or an engine vibration while stopped at idle with the transmission in Drive and their foot on the service brake
06-00-89-031D2021-04-20. Service bulletin. OEM and Remanufactured Engine and Automatic Transmission/Transaxle Identification