Service bulletin T-TT-0531-19

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.

The communication, as NHTSA indexes it (as of 2026-10-19)
Type	Service bulletin
NHTSA id	10158584
Published by NHTSA	2019-04-15
Manufacturer's number	T-TT-0531-19
Manufacturer's date	2019-03-13
NHTSA component	ELECTRICAL SYSTEM:12V/24V/48V BATTERY; ELECTRICAL SYSTEM

NHTSA's summary

TT: Some 2020 model year Japan built Corolla vehicles may exhibit a condition where the battery may become depleted during shipping. It has been discovered that when the D/C cut fuse is not installed voltage may continue to flow to an ECU while the vehicle is powered off causing a parasitic draw depleting battery state of charge.

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, 12-volt battery

Vehicles listed
TOYOTA COROLLA HATCHBACK	2020 (the catalog's model; the bulletin names a series or trim of it)

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-0687-22	2022-04-18. Service bulletin. TT: When customers have a concern about a discharged battery, no start, or general battery concern, the DCA-8000 is the only appropriate tool to use for diagnosis
T-SB-0095-20 Rev	2021-02-16. Service bulletin. TSB: Some 2020 model year Camry, Camry Hybrid, Corolla Hatchback, RAV4, and RAV4 Hybrid vehicles may exhibit one or more of the following conditions: ?Diagnostic Trouble Code (DTC) B15A804 is present in current or history. ?Red SOS LED stays on after bulb check. ?Toyota App does not accept the activation code. ?Toyota App is inoperative. ?SOS call center does not receive the vehicle?s location in a timely manner. ?Toyota App shows an error 42 when trying to execute a command. ?Unable to remote start the vehicle with the key fob (if equipped). ?Unable to subscribe to remote services. ?Unable to activate Wi-Fi. ?Destination Assist is inoperative Some 2020 ? 2021 model year Camry, Camry Hybrid, Corolla Hatchback, RAV4, and RAV4 Hybrid vehicles and some 2021 model year Avalon, Avalon Hybrid, Corolla, Corolla Hybrid, Sienna Hybrid, and Venza Hybrid vehicles may exhibit one or more of the following conditions: ?DTC B15A804 is present in current or history. ?Red SOS LED stays on after bulb check. ?Toyota App is inoperative. ?Unable to subscribe to remote services. ?Unable to activate Wi-Fi. ?Depleted 12V vehicle battery when in IG-OFF. Some 2020 ? 2021 model year Camry, Camry Hybrid, Corolla Hatchback, RAV4, and RAV4 Hybrid vehicles and some 2021 model year Avalon, Avalon Hybrid, Corolla, Corolla Hybrid, Sienna Hybrid, and Venza Hybrid vehicles may exhibit the following condition: ?Depleted 12V vehicle battery when in IG-OFF. A DCM reset and firmware update is now available to address these conditions. Follow the DCM Reset and Firmware Update Procedure in this bulletin to update the firmware.
T-SB-0095-20 Rev	2021-02-16. Service bulletin. TSB: Some 2020 model year Camry, Camry Hybrid, Corolla Hatchback, RAV4, and RAV4 Hybrid vehicles may exhibit one or more of the following conditions: ?Diagnostic Trouble Code (DTC) B15A804 is present in current or history. ?Red SOS LED stays on after bulb check. ?Toyota App does not accept the activation code. ?Toyota App is inoperative. ?SOS call center does not receive the vehicle?s location in a timely manner. ?Toyota App shows an error 42 when trying to execute a command. ?Unable to remote start the vehicle with the key fob (if equipped). ?Unable to subscribe to remote services. ?Unable to activate Wi-Fi. ?Destination Assist is inoperative. Some 2020 ? 2021 model year Camry, Camry Hybrid, Corolla Hatchback, RAV4, and RAV4 Hybrid vehicles and some 2021 model year Avalon, Avalon Hybrid, Corolla, Corolla Hybrid, Sienna Hybrid, and Venza Hybrid vehicles may exhibit one or more of the following conditions: ?DTC B15A804 is present in current or history. ?Red SOS LED stays on after bulb check. ?Toyota App is inoperative. ?Unable to subscribe to remote services. ?Unable to activate Wi-Fi. ?Depleted 12V vehicle battery when in IG-OFF. A DCM reset and firmware update is now available to address these conditions. Follow the DCM Reset and Firmware Update Procedure in this bulletin to update the firmware.
T-TT-0625-20	2020-11-23. Service bulletin. TT: A 12V Battery Discharged and / or Dead condition can be due to multiple causes. In order to properly diagnose and determine the root cause it?s important to follow a structured process to identify any contributing issues and determine the proper remedy.
T-SB-0074-20	2020-09-14. Service bulletin. TSB: Some 2003 ? 2020 model year Prius, Prius C, Prius V; 2006 ? 2019 model year Highlander Hybrid Vehicle; 2007 ? 2020 Camry Hybrid Vehicle; 2013 ? 2020 model year Avalon Hybrid Vehicle; 2016 ? 2020 model year Mirai and RAV4 Hybrid Vehicle; and 2020 model year Corolla Hybrid Vehicles may exhibit a MIL ON condition with Diagnostic Trouble Codes (DTCs) P0A80/P1AC000 and/or P0A7F/P1A8000 stored due to dust or debris buildup in the HV battery cooling fan and/or HV cooling filter. Follow the procedure in this bulletin to address this condition.
T-TT-0553-19 Rev	2020-08-24. Service bulletin. TT: The new DCA-8000 Diagnostic Charger may cause your facility?s Ground Fault Circuit Interrupter (GFCI) breaker to trip. A GFCI breaker can be tripped for various reasons, one of the reasons may be related to the DCA-8000. We are investigating this issue to determine the root cause. Other reasons the GFCI breaker may trip ?Circuit demand is too high for GFCI rating ?Worn out GFCI internal contacts ?Improper installation or wiring of GFCI breaker
T-SB-0006-19	2019-02-19. Service bulletin. TSB: Hybrid vehicles are equipped with two types of batteries: ? Hybrid Vehicle (HV) battery ? Auxiliary (12V) battery If the hybrid vehicle is put into storage, the State-Of-Charge (SOC) of its HV battery and auxiliary battery will gradually decrease. To prevent the auxiliary battery from becoming discharged during storage, proper maintenance is necessary. Perform the following maintenance service for the HV battery and auxiliary battery. NOTE ? BEFORE disconnecting the auxiliary battery, confirm the shift lever is in the ?P? position and apply the parking brake completely. The shift lever CANNOT be shifted from the ?P? position with the auxiliary battery disconnected. ? If the negative (?) terminal of the auxiliary battery is reconnected, even if the Power button is in the Start mode, the hybrid system may NOT start. In this case, push the Power button and select the Start mode again to start the hybrid system (the Ready light is ON). If the hybrid system still does NOT start (the Ready light is OFF), refer to the Repair Manual.