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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: Driver assistance are shown. Show all

Bulletins, newest first
TSB0104212024-04-01. Service bulletin. SERVICE BRAKES, HYDRAULIC; ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING:COOLING SYSTEM; LANE DEPARTURE. TSB: Some 2018 ? 2024 model year Toyota vehicles equipped with an A25A-FKS, A25A-FXS, M20A-FKS, or M20A-FXS 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]) present. 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-0726-232023-08-28. Service bulletin. BACK OVER PREVENTION; ENGINE AND ENGINE COOLING. TT: Some 2021 - 2023 Highlander HV, RAV4 HV and Sienna HV vehicles equipped with Rear Motor Generator, MGR (Q610), may duplicate an abnormal noise (Drone, Growl, Humming, and/or other) from the MGR at various vehicle speeds and normal drive conditions. Please contact TAS for diagnostic instructions to aid in resolution of the condition.
T-TT-0726-232023-04-17. Service bulletin. ENGINE AND ENGINE COOLING; BACK OVER PREVENTION. TT: Some 2021 - 2023 Highlander HV, RAV4 HV and Sienna HV vehicles equipped with Rear Motor Generator, MGR (Q610), may duplicate an abnormal noise (Drone, Growl, Humming, and/or other) from the MGR at various vehicle speeds and normal drive conditions. Please contact TAS for diagnostic instructions to aid in resolution of the condition.
T-SB-0115-22 Rev2023-04-17. Service bulletin. BACK OVER PREVENTION; FUEL SYSTEM, GASOLINE. TSB: Some 2019 ? 2022 model year Avalon, 2018 ? 2023 model year Camry, 2017 ? 2022 model year Highlander, and 2017 ? 2020 model year Sienna vehicles equipped with a 2GR-FKS engine may exhibit a knocking noise from the vacuum pump at idle.
T-SB-0008-222022-03-14. Service bulletin. AIR BAGS; LANE DEPARTURE. TSB: Some 2020 ? 2021 model year Highlander Hybrid vehicles may exhibit one or more of the following conditions: ?The fuel gauge displays less than full when the fuel nozzle automatically clicks off. ?The total amount of fuel dispensed while refueling is less than expected when the fuel nozzle automatically clicks off. ?The Low Fuel warning light illuminates sooner than expected. Additionally, the distance to empty mileage displayed in the Multi-Information Display (MID) may be less than expected. To address these concerns an updated fuel tank, fuel gauge bracket, and fuel sender gauge assembly were developed. Follow the procedures in this bulletin to address these conditions
T-TT-0593-20 Rev2022-02-14. Service bulletin. ELECTRICAL SYSTEM:ADAS:DRIVER MONITORING:SOFTWARE; ELECTRICAL SYSTEM. TT: Some customers may experience the inability to activate Remote Connect or Remote Connect becoming inoperative when attempting to send commands to the vehicle. To simplify the diagnosis of this system and prevent the unnecessary replacement of parts, please refer to the procedure below.
T-TT-0663-212021-10-25. Service bulletin. LANE DEPARTURE; VISIBILITY. TT: When used in conjunction with the Repair Manual, these Blind Spot Monitor, Forward Recognition Camera, and Front Millimeter Wave Radar tips leverage SSTs and readily available tools to support target placement in varying shop environments.
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-0146-19 Rev2021-02-16. Service bulletin. SEAT BELTS; BACK OVER PREVENTION. TSB: Some 2020 ? 2021 model year Tundra vehicles equipped with Audio Plus (version 1186) or earlier may exhibit one or more of the following conditions: ?WiFi intermittently inoperative. ?DTC B15DB present. ?Changing the Auto Relock Timer setting also changes the Remote 2-Press unlock setting. Some 2020 ? 2021 model year Tundra, RAV4, RAV4 Hybrid, Highlander, or Highlander Hybrid vehicles equipped with Audio Plus (version 1210), or Premium Audio (version 1196) or earlier may exhibit one or more of the following conditions: ?Intermittent screen flashing. ?Intermittent ?Destination Assist Unavailable? pop-up message. ?Intermittent blank screen. ?Bluetooth® intermittently disconnects. ?Abnormal radio playback after Destination Assist Call. ??There is no playable data? pop-up message when using USB Audio. ?Unable to answer phone calls when using Apple CarPlay®. ?Clock displays the incorrect time. ?Intermittent rebooting. ??The software version doesn?t correspond? pop-up is intermittently displayed. ?Intermittent black screen when using projection navigation. ?Abnormal noise after ACC OFF/ON when using AM mode and high volume. ??Please connect USB? pop-up message when USB is already connected. A software update is now available to address these conditions. Follow the Software Update Procedure in this bulletin to update the software.
T-TT-0599-20 Rev2021-02-16. Service bulletin. BACK OVER PREVENTION:SOFTWARE. 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-TT-0537-19_Rev2020-05-11. Service bulletin. VISIBILITY; LANE DEPARTURE. TT: The blind spot monitor (BSM) sensor angle inspection is used to confirm that the BSM sensor is within the specified angle before performing axis beam adjustment. When used in conjunction with the repair manual, these BSM tips leverage SSTs and readily available tools to support sensor angle confirmation in varying shop environments.

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