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Service bulletin T-TT-0639-21

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 id10188911
Published by NHTSA2021-03-15
Manufacturer's numberT-TT-0639-21
Manufacturer's date2021-02-02
NHTSA componentPOWER TRAIN

NHTSA's summary

TT: Customers may state they have a fluid leak from under the vehicle or technicians may notice a leak while performing other work.

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

Vehicles listed
TOYOTA SUPRA2020, 2021

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
T-TT-0591-202020-02-24. Service bulletin. TT: A message to replace the battery may indicate on the dash. This message can display when the voltage drops too low and is to assure the customer receives the vehicle with a fully charged battery. Due to the high amp draw when the vehicle is not shut down, this vehicle depletes the battery charge much quicker than other Toyota vehicles, so dealers must use care to maintain battery charge on their lot. Care should be made to use the key fob to lock the vehicle upon every exit of the vehicle. If you are going to remain in the vehicle, press and hold the power button on the radio.
T-SB-0151-192019-11-18. Service bulletin. TSB: Flash reprogramming allows the Electric Control Unit (ECU) software to be updated without replacing the ECU. Flash calibration updates for the Supra are released as field-fix procedures described in individual service bulletins. This bulletin details the ECU flash reprogramming process and outlines use of the Toyota-ISTA Diagnostic Software. BEFORE beginning any reprogramming, ensure that the latest version of Toyota-ISTA is downloaded and installed from TIS. NOTE ECU is a Toyota term used to describe integrated computerized devices responsible for managing the operation of a system or subsystem. For the purposes of this bulletin, the term ?ECU? is used as a generic label for the following SAE J1930 standard references: ? Powertrain Control Module (PCM) ? Engine Control Module (ECM) ? Transmission Control Module (TCM) ? Any other Toyota specific control unit