Service bulletin 21TC06 - Dealer

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)
Type	Service bulletin
NHTSA id	10202498
Published by NHTSA	2021-10-25
Manufacturer's number	21TC06 - Dealer
Manufacturer's date	2021-09-30
NHTSA component	SERVICE BRAKES, HYDRAULIC; ELECTRICAL SYSTEM:SOFTWARE

NHTSA's summary

DP: One of the Pre-Collision System (PCS) features in your vehicle is called ?pre-collision brake assist.? When you apply some pressure to the brake pedal, this feature of the system can automatically help further reduce speed if sensors detect the possibility of a crash. Due to incorrect software programming, there could be a delay in the activation of pre-collision brake assist, resulting in less overall vehicle speed reduction. However, the other features of PCS (the pre-collision warning and pre-collision braking) are not affected by this programming error.

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

Brakes, Electrical system, Software

Vehicles listed
TOYOTA PRIUS	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
TSB003120Rev2	2022-06-21. Service bulletin. TSB: Some 2017 ? 2018 model year Prius Prime vehicles equipped with Premium Audio (R10A5430) or earlier may exhibit one or more of the following conditions. Updated multimedia software is now available to address these conditions. Follow the Multimedia Software Update Procedure in this bulletin to install the latest software version.
21TC06-RL_Publis	2022-01-18. Service bulletin. RL: One of the Pre-Collision System (PCS) features in your vehicle is called ?pre-collision brake assist.? When you apply some pressure to the brake pedal, this feature of the system can automatically help further reduce speed if sensors detect the possibility of a crash. Due to incorrect software programming, there could be a delay in the activation of pre-collision brake assist, resulting in less overall vehicle speed reduction. However, the other features of PCS (the pre-collision warning and pre-collision braking) are not affected by this programming error.
21TC06-RL publi	2021-10-25. Service bulletin. RL: One of the Pre-Collision System (PCS) features in your vehicle is called ?pre-collision brake assist.? When you apply some pressure to the brake pedal, this feature of the system can automatically help further reduce speed if sensors detect the possibility of a crash. Due to incorrect software programming, there could be a delay in the activation of pre-collision brake assist, resulting in less overall vehicle speed reduction. However, the other features of PCS (the pre-collision warning and pre-collision braking) are not affected by this programming error.
T-TT-0629-20	2020-11-30. Service bulletin. TT: Some 2020 ? 2021 model year C-HR, RAV4, RAV4 HV, Sequoia, Tundra and 2021 model year Avalon, Avalon HV, Prius, Prius Prime, and RAV4 Prime vehicles may exhibit inoperative Apple CarPlay® with only iPhone® 12 devices (iPhone® 12, iPhone® 12 Max, iPhone® 12 Pro, or iPhone® 12 Pro Max).
T-SB-0039-20 Rev	2020-11-30. Service bulletin. TSB: An initialization procedure is required to activate the Entune? 3.0 App Suite Connect for Audio, Audio Plus, and Premium Audio head units before they are used for the first time on new vehicles. The initialization procedure may also be performed under other circumstances, such as following a head unit replacement or after the customer?s personal settings are erased. The initialization procedure requires between 3 and 15 minutes to complete, depending on file size, cellular connection speed, and other factors. Following the initialization procedure, individual Entune? 3.0 apps may periodically update through an over-the-air update system. Updates are either optional or mandatory. The update procedure will take approximately 1 minute for each app requiring an update. Follow the Initialization/Update Procedure in this bulletin to perform the initialization and app updates.
T-SB-0039-20 Rev	2020-08-17. Service bulletin. TSB: An initialization procedure is required to activate the Entune? 3.0 App Suite Connect for Audio, Audio Plus, and Premium Audio head units before they are used for the first time on new vehicles. The initialization procedure may also be performed under other circumstances, such as following a head unit replacement or after the customer?s personal settings are erased. The initialization procedure requires between 3 and 15 minutes to complete, depending on file size, cellular connection speed, and other factors. Following the initialization procedure, individual Entune? 3.0 apps may periodically update through an over-the-air update system. Updates are either optional or mandatory. The update procedure will take approximately 1 minute for each app requiring an update. Follow the Initialization/Update Procedure in this bulletin to perform the initialization and app updates.