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Service bulletin 21NA033

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 id10212566
Published by NHTSA2022-05-31
Manufacturer's number21NA033
Manufacturer's date2021-12-15
NHTSA componentPOWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM); POWER TRAIN

NHTSA's summary

This service bulletin provides a procedure to perform a transmission solenoid clean procedure 3 times depending on what DTC has 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

Transmission and driveline, Automatic transmission, Transmission control module

Vehicles listed
CHEVROLET CORVETTE2020, 2021, 2022

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
PIP5781A2024-02-12. Service bulletin. This Preliminary information communicates that characterizing certain parts is no longer required, the service instruction was changed but technicians are still trying to perform the function causing further confusion.
17-NA-0662023-07-25. Service bulletin. This service bulletin provides information for automatic transmission Oil Cooler Flush and flow test.
N2123369622023-03-08. Service bulletin. Emission Recall. General Motors has decided to conduct a Voluntary Emission Recall involving certain vehicles. The Transmission Control Module (TCM), after detecting a loss of communications fault with other control modules, may incorrectly clear the loss of communications Diagnostic Trouble Codes (DTCs) when the vehicle is keyed off and, if the loss of communications fault persists, may not detect it again when the vehicle is keyed back on. If this were to happen, the transmission could operate in a default mode with no DTC set and the MIL not illuminated. Dealers are to reprogram the Transmission Control Module (TCM) with updated software.
PIE07402023-03-08. Service bulletin. This engineering information (EI) is requesting information from technicians to perform the check list provided and contact the engineer listed in regards to the Service Transmission Message and/or Check Engine Lamp illuminated on the Driver Information Center (DIC) and having multiple DTCs set.
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.
PIE0690A2022-05-18. Service bulletin. This engineering information (EI) closure ends the need for further information from the field in regards to a Transmission Hot message displayed on DIC and/or Vehicle Will Not Disengage from Park, DTCs P0606, P0607 Set.
PIP5797C2022-03-14. Service bulletin. This Preliminary information communicates the need to replace the transmission assembly for faults related to non-serviceable internal parts..
PIE06692022-01-03. Service bulletin. This engineering information (EI) is requesting dealership personnel that when it comes to the scheduled maintenance at 12,070 km (7500 mi), or within the first year of ownership, to send engineering the Dual Clutch Canister Transmission Filters for inspection after replacement.
PIP5818A2021-12-13. Service bulletin. This Preliminary information communicates additional diagnostics for P1789.
990420002L2021-08-09. Service bulletin. This service bulletin provides information on Driveline Clunk Noise and what is acceptable and what is considered normal operation.