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Service bulletins for the 2020 Toyota Avalon

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.

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

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

Bulletins, newest first
T-SB-0106-22 Rev22026-02-11. Service bulletin. ELECTRICAL SYSTEM. OBSOLETE NOTICE January 30, 2026: This bulletin is now obsolete. Please see T-SB-0001-26.
T-SB-0001-262026-02-11. 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-SB-0058-23 Rev12025-07-10. 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-0780-252025-06-06. 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-0780-252025-05-15. 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 Rev22025-04-08. 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.
T-SB-0013-24 Rev12025-04-08. Service bulletin. ELECTRICAL SYSTEM. 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-0106-22 Rev22025-03-11. 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. The SST is used with applicable vehicles to deliver the update, however, the process for generating license keys differs from previous generations.
T-SB-0013-24 Rev12025-03-11. Service bulletin. ELECTRICAL SYSTEM. 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-0754-242024-07-06. Service bulletin. ELECTRICAL SYSTEM. Customers have expressed concerns about the performance of Qi Wireless Chargers. Wireless chargers on applicable vehicles are designed to work with Qi Certified devices only. MagSafe devices, that are not Qi Certified, may not charge as expected with Qi Wireless Chargers.
T-TT-0754-242024-07-06. Service bulletin. ELECTRICAL SYSTEM. Customers have expressed concerns about the performance of Qi Wireless Chargers. Wireless chargers on applicable vehicles are designed to work with Qi Certified devices only. MagSafe devices, that are not Qi Certified, may not charge as expected with Qi Wireless Chargers.
T-SB-0064-18 Obs2024-04-15. Service bulletin. ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER. OBSOLETE NOTICE March 11, 2024: This bulletin is now obsolete. Please see T-SB-0013-24.
T-SB-0013-242024-04-15. Service bulletin. ELECTRICAL SYSTEM. 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.
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.
TSB008523A2023-12-26. Service bulletin. ELECTRICAL SYSTEM:PROPULSION SYSTEM:HYBRID MANAGEMENT; ELECTRICAL SYSTEM. TSB: Some 2016 ? 2023 model year Toyota vehicles may exhibit a hybrid system warning lamp occurring in below-freezing temperatures (below 32°F or 0°C). After performing a Health Check, one or both of the following Diagnostic Trouble Codes (DTCs) may be present: ?P1C8449 ? (High Voltage Power Resource Circuit Short during Ready ON) ?P300449 ? (High Voltage Power Resource Circuit Short during Pre-Charge) Follow the Repair Procedure in this bulletin to address this condition.
TSB0085232023-12-26. Service bulletin. ELECTRICAL SYSTEM. TSB: Some 2016 ? 2023 model year Toyota vehicles may exhibit a hybrid system warning lamp occurring in below-freezing temperatures (below 32°F or 0°C). After performing a Health Check, one or both of the following Diagnostic Trouble Codes (DTCs) may be present: ?P1C8449 ? (High Voltage Power Resource Circuit Short during Ready ON) ?P300449 ? (High Voltage Power Resource Circuit Short during Pre-Charge) Follow the Repair Procedure in this bulletin to address this condition.
T-TT-0708-222022-10-17. Service bulletin. ENGINE AND ENGINE COOLING; ELECTRICAL SYSTEM. TT: Some Model Year 2018-2022 vehicles equipped with A25A-FKS or A25A-FXS engines may experience a MIL ON condition with the following DTCs: P043F00, P043E00, P24007E, P24007F, P24187E
T-SB-0110-20 Rev2022-06-13. Service bulletin. ELECTRICAL SYSTEM:PROPULSION SYSTEM:TRACTION BATTERY; EQUIPMENT. TSB: This bulletin includes basic procedures for performing a rescue charge at battery 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-TT-0694-222022-05-16. Service bulletin. ELECTRICAL SYSTEM. TT: After jump-starting, the vehicle may experience a no-start condition and multiple DTCs including U010087. Upon investigation, it is found that the engine ECU has been damaged and needs to be replaced (Fig 1). In several cases, it was found that the cause of the ECU damage was improper jump starting. Further investigation found that ECU damage may occur if the jumper cables are hooked up on or around the engine ECU or ECU mounting bracket
T-TT-0687-222022-04-18. Service bulletin. ELECTRICAL SYSTEM:12V/24V/48V BATTERY. 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-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-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-SB-0071-20 Rev2021-06-21. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT; ELECTRICAL SYSTEM. TSB: Some 2019 model year Avalon and Avalon Hybrid vehicles equipped with Entune? Audio Plus (version 1002) or Entune? Premium Audio (version 1002) or earlier may exhibit one or more of the following conditions: ?Incorrect GPS date and time. ?Abnormal Bluetooth® operation. ?Abnormal Wi-Fi operation. ?Microphone remains on the screen after voice recognition failure. ?Unable to see text with headlights on (text is the same color as the background). Some 2019 ? 2020 model year Toyota vehicles equipped with Entune? Audio (version 1007), Entune? Audio Plus (version 1011), or Entune? Premium Audio (version 1011) or earlier may exhibit one or more of the following conditions: ?Phone does not auto-connect on startup. ?Intermittent black screen. ?Apple CarPlay® home screen widget turns white when USB flash drive is disconnected. ?Abnormal phone book sorting. ?Unable to see DCM Status when in dark red or dark blue modes. ?XM no signal banner appears at all times. ??Check antenna,? ?ID Displaying,? or ?Seeking? always displays on XM mode. ?Unable to switch Bluetooth® devices. ?Apps button is inactive in the voice recognition hint screen when using Apple CarPlay®. ?Incorrect Spanish translations. ?Voice recognition is not canceled during a phone call. ?Low Easy Speak volume. ?Voice recognition ?Web Search? is inoperative. ?Entune? apps are inoperative and ?When it is safe and legal to do so, please ensure your Entune? App Suite application is running and logged in on your phone? pop-up appears. ?Download screen appears even though nothing is being downloaded. ?Intermittent partially white screen. ?Screen intermittently locked. ?Text goes off the edge of the screen. ?Screen is black for 10 seconds after shifting out of Reverse when using Apple CarPlay® A software update is now available to address these conditions. Follow the Software Update Procedure in this bulletin to update the softwa
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-0001-212021-02-16. Service bulletin. AIR BAGS; ELECTRICAL SYSTEM. TSB: Some 2019 ? 2021 model year Avalon and Avalon Hybrid vehicles may exhibit a condition where the driver side and/or passenger side LED parking lights do not fully illuminate when the headlight switch and the engine are on and the vehicle is in reverse. Follow the Repair Procedure in this bulletin to address this condition.

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