WenmarOpen by Wenmar Pro

Service bulletins for the 2021 Toyota Mirai

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.

121 on file from NHTSA, as of 2026-10-19.

By type

By component

By trouble code

Only bulletins with component: Electrical system are shown. Show all

Bulletins, newest first
22TC042022-06-21. Service bulletin. ELECTRICAL SYSTEM; ELECTRICAL SYSTEM:SOFTWARE. TI: TECHNICAL INSTRUCTIONS SPECIAL SERVICE CAMPAIGN 22TC04 SOFTWARE UPDATE FOR EV CONTROL COMPUTER CERTAIN 2021 MODEL YEAR MIRAI VEHICLES
T6232022-06-21. Service bulletin. ELECTRICAL SYSTEM. DD: SPECIAL SERVICE CAMPAIGN 22TC04 (Remedy Notice) Dealer Letter and Technical Instructions Available on TIS Certain 2021 Model Year Mirai Software Update for the EV Control Computer
MEMORANDUM2022-06-21. Service bulletin. ELECTRICAL SYSTEM. TI: TECHNICAL INSTRUCTIONS SPECIAL SERVICE CAMPAIGN 22TC04 SOFTWARE UPDATE FOR EV CONTROL COMPUTER CERTAIN 2021 MODEL YEAR MIRAI VEHICLES
22TC04 Remedy No2022-06-21. Service bulletin. ELECTRICAL SYSTEM. RL: Due to improper programming in the EV Control Computer, under certain conditions, the vehicle may not start. A warning message will be displayed in the instrument panel display
22TC042022-06-21. Service bulletin. ELECTRICAL SYSTEM. DL: Due to improper programming in the EV Control Computer, under certain conditions, the vehicle may not start. A warning message will be displayed in the instrument panel display
T-TT-0599-20 Rev2022-04-18. Service bulletin. ELECTRICAL SYSTEM. TT: Vehicle control apps might not operate as expected at times due to preconditions (normal operating parameters) not being established, vehicle settings and/or network/cellular coverage concerns
T-SB-0003-222022-02-14. Service bulletin. ELECTRICAL SYSTEM:WIRING. TSB This Service Bulletin includes guidelines meant to help determine whether to repair or replace a wire harness assembly based on damage type. This Service Bulletin should be used in conjunction with the applicable model and model year Electronic Wiring Diagram (EWD) and/or Repair Manual.
T-SB-0080-212021-10-25. Service bulletin. ELECTRICAL SYSTEM. TSB: Some 2021 model year Mirai vehicles may exhibit a MIL ON condition with Diagnostic Trouble Code (DTC) P060A47 (Hybrid/EV Battery Energy Control Module Monitoring Processor Watchdog / Safety MCU Failure) present. The Fuel Cell Vehicle (FCV) control computer logic has been modified to reduce the possibility of this condition. Follow the Repair Procedure in this bulletin to address this condition.
T-SB-0118-202021-01-25. Service bulletin. EQUIPMENT; STRUCTURE; ELECTRICAL SYSTEM. TSB: Pre-Delivery Service (PDS) is a critical step in satisfying our new car customers. Customer feedback indicates the following areas deserve special attention when performing PDS: ?Careful inspection for paint chips/scratches and body dents/dings. ?Proper operation of electrical accessories (including interior light, clock, and radio reset). ?Interior cleanliness. ?Proper function of mechanical systems. Customer retention and proper maintenance of vehicles are and have always been a major focus for Toyota. To help remind customers that regular service is essential to the proper maintenance of the vehicle, dealers are required to install a service reminder sticker before delivery. By doing this, customers will be reminded to return to your dealership for service. Your current service reminder sticker may be used. (See PDS Check Sheet item 8 of ?Final Inspection and Cleaning.?) This bulletin contains the PDS procedures which apply specifically to 2021 model year Mirai vehicles. A universal PDS Check Sheet that contains PDS steps that apply to all 2021 model year Toyota vehicles has been developed. To properly perform a complete PDS, you must complete all procedures contained in this TSB as well as the universal PDS Check Sheet. In addition, if the vehicle is stored for over 30 days, be sure to follow Long-Term Vehicle Storage Guidelines.
T-SB-0039-20 Rev2020-11-30. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE. 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 Rev2020-08-17. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE. 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-0040-20 Rev2020-07-27. Service bulletin. ELECTRICAL SYSTEM:12V/24V/48V BATTERY. 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.
T-SB-0064-18 Rev2020-07-27. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE; EQUIPMENT:ELECTRICAL:ANTI-THEFT DEVICES. TSB: The Immobilizer and Smart Key Reset is a feature that allows the registration of new keys when all master keys are lost. Once the system is reset, all previously registered keys will be erased and can never be reused. Another feature, Add/Remove Key, is also available. Once a key is removed, it can never be reused.
T-SB-0040-202020-05-11. Service bulletin. ELECTRICAL SYSTEM. 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.
T-SB-0035-202020-05-11. Service bulletin. ELECTRICAL SYSTEM. TSB: A battery in a stored vehicle is subject to conditions that can reduce its performance and service life. These conditions include storage period, temperature, parasitic drain, and battery load. Because of these factors, battery inspection and maintenance are required in order to ensure proper operation and optimal battery life. As a matter of policy, Toyota does not provide battery warranty coverage for discharged and/or failed batteries due to lack of maintenance. It is the dealer?s responsibility to maintain the specified State-Of-Charge (SOC) of the vehicle?s battery while in stock and ensure proper SOC at delivery. To eliminate customer service concerns due to an undercharged battery during the first few weeks of ownership, ALL dealers should check battery SOC and recharge, if necessary, no more than 48 hours before delivery to the customer.

The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.