# Service bulletin T\-TT\-0574\-19

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.

- Type: Service bulletin
- NHTSA id: 10166024
- Published by NHTSA: 2019\-10\-15
- Manufacturer's number: T\-TT\-0574\-19
- Manufacturer's date: 2019\-09\-18
- NHTSA component: EQUIPMENT; ELECTRICAL SYSTEM

## NHTSA's summary

TT: Some customers may experience poor outgoing Bluetooth sound quality, this can occur for various reasons. Current multimedia systems are designed with the ability to adjust Bluetooth sound quality to compensate for echo or excessive background noise.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2019/MC-10166024-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2019/MC-10166024-9999.pdf)

The document is the manufacturer's. This site does not hold it.

## Components

Electrical system, Equipment and accessories

## Vehicles listed

- 2014 to 2019 TOYOTA 4RUNNER
- 2015 to 2018 TOYOTA AVALON
- 2014 to 2017 TOYOTA CAMRY
- 2014 to 2019 TOYOTA COROLLA
- 2014 to 2019 TOYOTA HIGHLANDER
- 2016 to 2017 TOYOTA MIRAI
- 2016 to 2019 TOYOTA PRIUS
- 2015 to 2017 TOYOTA PRIUS C
- 2019 TOYOTA PRIUS PRIME
- 2015 to 2017 TOYOTA PRIUS V
- 2018 TOYOTA PRIUS V
- 2014 to 2018 TOYOTA RAV4
- 2017 TOYOTA RAV4 HYBRID
- 2015 to 2019 TOYOTA SEQUOIA
- 2015 to 2017 TOYOTA SIENNA
- 2014 to 2019 TOYOTA TACOMA
- 2014 to 2019 TOYOTA TUNDRA
- 2015 TOYOTA VENZA
- 2018 to 2019 TOYOTA YARIS
- 2016 TOYOTA redundant RAV4 HV

## Recalls for the same vehicles and component

- [25V876000](/recalls/nhtsa/25V876000.md), 2025-12-17: EQUIPMENT ADAPTIVE/MOBILITY:WHEELCHAIR RESTRAINTS/SECUREMENT:LATCH/ANCHOR:
- [2023589](/recalls/tc/2023589.md), 2023-11-01: Electrical
- [23V734000](/recalls/nhtsa/23V734000.md), 2023-11-01: ELECTRICAL SYSTEM:12V/24V/48V BATTERY
- [2021723](/recalls/tc/2021723.md), 2021-11-24: Electrical
- [21V688000](/recalls/nhtsa/21V688000.md), 2021-09-02: EXTERIOR LIGHTING:HEADLIGHTS; ELECTRICAL SYSTEM:WIRING
- [20V410000](/recalls/nhtsa/20V410000.md), 2020-07-15: EXTERIOR LIGHTING:TURN SIGNAL; ELECTRICAL SYSTEM:WIRING
- [2020284](/recalls/tc/2020284.md), 2020-06-25: Electrical
- [19V876000](/recalls/nhtsa/19V876000.md), 2019-12-11: ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL
- [2019434](/recalls/tc/2019434.md), 2019-08-28: Electrical
- [2019428](/recalls/tc/2019428.md), 2019-08-23: Accessories

## Other bulletins for the same vehicles and component

- [T\-SB\-0106\-22 Rev2](/bulletins/11028726.md), 2026-02-11, Service bulletin: ELECTRICAL SYSTEM. OBSOLETE NOTICE January 30, 2026: This bulletin is now obsolete. Please see T\-SB\-0001\-26.
- [T\-SB\-0001\-26](/bulletins/11028722.md), 2026-02-11, Service bulletin: ELECTRICAL SYSTEM. Some 2018 – 2024 model year Toyota vehicles equipped with a Premium Audio with Dynamic Navigation System require a Special Service Tool \(SST\) USB flash drive to update the map, points of interest, and system software.
- [T\-TT\-0790\-25](/bulletins/11022964.md), 2025-09-09, Service bulletin: ELECTRICAL SYSTEM. Some customers may experience echoing on the line calling the vehicle when using Bluetooth Hands Free. This is caused by the phone Hands Free volume being too low.
- [T\-SB\-0010\-24 Rev2](/bulletins/11020670.md), 2025-07-10, Service bulletin: ELECTRICAL SYSTEM. Some 2021 – 2022 model year Avalon, 2018 – 2024 Camry, 2019 – 2025 model year Corolla, 2022 – 2025 model year Corolla Cross, and 2019 – 2025 model year RAV4 vehicles with A25A\-FKS and M20A\-FKS engines may have a MIL ON condition with one or more of the following Diagnostic Trouble Codes \(DTCs\) upon cold soak start up with engine coolant temperatures between 14°F – 41°F: •P030027 – Random/Multiple Cylinder Misfire Detected \(Emission\) Signal Rate of Change Above Threshold •P030000 – Random/Multiple Cylinder Misfire Detected •P030100 – Cylinder 1 Misfire Detected •P030200 – Cylinder 2 Misfire Detected •P030300 – Cylinder 3 Misfire Detected •P030400 – Cylinder 4 Misfire Detected
- [21TG01](/bulletins/11020667.md), 2025-07-10, Service bulletin: ELECTRICAL SYSTEM. Campaign Expired \- replaced with campaign 23TA13TECHNICAL INSTRUCTIONS FOR CONSUMER ADVISORY 21TG01 12\-VOLT BATTERY SIZE AND INSTALLATION INSPECTION CERTAIN 2013 – 2018 RAV4
- [21TG01](/bulletins/11020666.md), 2025-07-10, Service campaign: ELECTRICAL SYSTEM. 21TG01 Exprired \- Replaced with Campaign 23TA13 During a recent investigation of reported battery fires in 2013\-2018 RAV4 vehicles with gasoline engines \(excluding hybrid models\), Toyota discovered that many non\-Toyota retailers and others who sell or install replacement batteries were recommending a small size battery for replacement. Toyota specifies a particular size replacement battery for the RAV4 that does not include this small size. The smaller battery may not fit securely with the RAV4’s battery mounting parts, and, in some cases, can move around when the vehicle is driven, causing a short circuit. Using the wrong size battery, or not installing a replacement battery properly, can cause damage to the battery and the vehicle, and it could cause a vehicle fire.
- [T\-SB\-0058\-23 Rev1](/bulletins/11020657.md), 2025-07-10, Service campaign: ELECTRICAL SYSTEM. The air conditioning dye injection tool kit has been developed to aid in identifying the location of air conditioning refrigerant leaks. The procedures outlined in this Service Bulletin aid in locating, inspecting, and repairing refrigerant leaks.
- [T\-TT\-0780\-25](/bulletins/11019332.md), 2025-06-06, Service bulletin: ELECTRICAL SYSTEM. To assist with the early detection and early resolution of audio related concerns you may be asked to recover MMR data from the head unit. The following steps are instructions on how to retrieve the data from the system and are only to be used when requested by FTS and/or FPE.
- [T\-TT\-0780\-25](/bulletins/11018329.md), 2025-05-15, Service bulletin: ELECTRICAL SYSTEM. To assist with the early detection and early resolution of audio related concerns you may be asked to recover MMR data from the head unit. The following steps are instructions on how to retrieve the data from the system and are only to be used when requested by FTS and/or FPE.
- [T\-SB\-0106\-22 Rev2](/bulletins/11016786.md), 2025-04-08, Service bulletin: ELECTRICAL SYSTEM. Some 2018 – 2024 model year Toyota vehicles equipped with a Premium Audio with Dynamic Navigation System require a Special Service Tool \(SST\) USB flash drive to update the map, points of interest, and system software. The SST is used with applicable vehicles to deliver the update, however, the process for generating license keys differs from previous generations.

JSON: [/v1/bulletins/10166024](/v1/bulletins/10166024)

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