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Service bulletins for the 2021 Toyota Highlander

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.

231 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
T-SB-0104-212022-01-18. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT; ENGINE. TSB: Some 2018 ? 2022 model year Toyota vehicles equipped with an A25A-FKS, A25A-FXS, or M20A-FKS engine may exhibit one or more of the following conditions: ?Milky/Discolored engine oil. ?An ?Oil Pressure Low? warning message on the Multi-information Display (MID). ?A MIL ON condition with Diagnostic Trouble Codes (DTCs) P05202A (Engine Oil Pressure Sensor/Switch "A" Signal Stuck in Range) and/or P052477 (Engine Oil Pressure too low [Severe]). Moisture from blow-by gases condenses and accumulates in the engine oil during short trips in extreme cold weather. When the moisture in the oil freezes, the oil pressure may drop, and the aforementioned warning indicators may display. Follow the procedures in this bulletin to address these conditions.
T-TT-0665-212021-10-25. Service bulletin. ELECTRICAL SYSTEM:INSTRUMENT PANEL:FUEL GAUGE. TT: Special Service Campaign 21TC05 applies to the following condition: The fuel gauge needle and the ?distance to empty? estimated in the vehicle display accurately indicate the approximate amount of remaining fuel in the fuel tank. However, some drivers are continuing to drive after the low fuel light illuminates, causing them to potentially run out of fuel and be inconvenienced. NOTE: Highlander HV fuel gauge issues, such as, fuel gauge not reading full or tank capacity does not meet expectations DO NOT apply to 21TC05.
T-TT-0650-212021-06-21. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. TT: Some vehicles equipped with Premium Audio systems may experience an inoperative condition that consists of displaying a ?Loading?? then a blank screen when pressing the MAP button. When performing the Storage Check in the Radio Diagnostic Menu, the MEU Storage Check displays: NG.
T-TT-0611-20 Rev2021-06-21. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT:ELECTRICAL:NAVIGATIONAL SYSTEM(GLOBAL POSITIONING SYSTEM). TT: To assist with the early detection and early resolution of audio related concerns, it may be requested as part of the remanufactured head unit return 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 audio suppliers, FTS, and/or FPEs.
T-SB-0025-212021-06-21. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM; EQUIPMENT ADAPTIVE/MOBILITY. TSB: Some 2020 ? 2021 model year vehicles equipped with Audio, Audio Plus, or Premium Audio (versions 1784) or earlier may exhibit one or more of the following conditions: ?Intermittent blank screen. ?Navigation map update fails. ?Album art inoperative. ?Pause function intermittently inoperative in CD mode. ?Intermittent DTC B15FE present. ?Abnormal energy flow screen appearance on Hybrid models. ?Abnormal phone call operation during Apple CarPlay®. ??No Information? displayed in Information Screen. ?No audio after voice guidance in Android Auto. ?Abnormal charging scheduling operation on RAV4 Prime models. ?Abnormal XM operation when using Apple CarPlay®. Follow the Multimedia Software Update Procedure in this bulletin to install the latest software version.
T-TT-0599-20 Rev2021-04-19. Service bulletin. ELECTRICAL SYSTEM; BACK OVER PREVENTION. 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-0066-20 Rev2021-01-25. Service bulletin. EQUIPMENT; PARKING BRAKE; ELECTRICAL SYSTEM. TSB: Some 2020 model year vehicles equipped with Audio Plus (version 1060) or Premium Audio (version 1060) or earlier may exhibit the following concern: ?Distorted screen when using Apple CarPlay® while making a hands-free phone call. Some 2020 model year vehicles equipped with Audio Plus (version 1021) or Premium Audio (version 1021) or earlier may exhibit one or more of the following conditions: ?Barge in function defaulted to OFF. ?Limited phone book grammar. ?Difficult Hand Free operation. ?Abnormal Electronic Owner?s Manual operation ?Music does not automatically resume when using Android Auto?. ?Cover a. rt is not displayed. ?Vehicle position is not sent to Destination Assist server. ?System inoperative after using the return button when using voice recognition Some 2020 model year vehicles equipped with Audio Plus (version 1035) or Premium Audio (version 1035) or earlier may exhibit one or both of the following conditions: ?Abnormal screen play while using Apple CarPlay® (primarily during phone calls). ?Poor sound quality during phone calls while using Apple CarPlay®. Some 2020 model year vehicles equipped with Audio Plus (version 1047) or Premium Audio (version 1047) or earlier may exhibit one or more of the following conditions: ?USB audio does not resume after ignition cycle. ?Intermittent rebooting. ?Bluetooth disconnecting during a phone call when using Apple CarPlay®. ?Intermittent screen freezing. ?Navigation intermittently will not boot up. ?Home Screen Audio widget is blank after a Destination Assist call. ?Song, artist, or album data missing. ?Abnormal clock operation. ?Apple CarPlay® intermittently inoperative. ?Radio takes a long time to boot up. A software update is now available to address these conditions. Follow the Software Update Procedure in this bulletin to update the software
T-TT-0634-202020-12-21. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT. TT: Some vehicles may experience an issue related to the DCM, the following information is consolidating the available diagnostic information in one document.
T-SB-0110-202020-12-21. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. TSB: This bulletin includes basic procedures for performing an at battery rescue charge on high voltage (HV) Ni-MH and Li-ion batteries. This bulletin should be used in conjunction with the applicable model and model year Repair Manual while performing the battery rescue charge. The GRX-5100 should be used wherever the Repair Manual references the Toyota Hybrid System (THS) charger.
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-0087-202020-10-26. Service bulletin. EQUIPMENT; 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 Highlander and Highlander Hybrid 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 Rev2020-08-17. 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-TT-0611-202020-06-22. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. TT: To assist with the early detection and early resolution of audio related concerns, it may be requested as part of the remanufactured head unit return 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 audio suppliers, FTS, and/or FPEs.
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.