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Service bulletins for the 2018 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.

185 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-TT-0549-192019-07-15. Service bulletin. ELECTRICAL SYSTEM. TT: The new 12V Battery Warranty Testers (DSS-5000 & DCA-8000) require certain information to generate a test result and warranty code. Below is an explanation of what information is required when testing a 12V battery on the new Warranty Battery Testers.
T-TT-0484-18-Rev2019-03-25. Service bulletin. ELECTRICAL SYSTEM. TT: Some customers may experience echoing on the line calling the vehicle when using Bluetooth Hands Free. This is caused by the phone Hands Free volume being too low. These settings may need to be reapplied any time the phone is paired to a new head unit, a phone update is applied, or the phone is un-paired and re-paired.
T-TT-0414-16-Rev2019-03-25. Service bulletin. EQUIPMENT:ELECTRICAL; EQUIPMENT; ELECTRICAL SYSTEM. TT: Some customers may encounter Bluetooth® connectivity concerns such as: ? Difficulty to pair the phone. ? Intermittent Bluetooth® failure to connect to the vehicle when first turning on the vehicle. ? Various Bluetooth® Audio functions are no longer functioning with customer?s phone such as ability to change the track using the steering wheel controls. These concerns can be caused by changes made on the customer?s phone. Make sure to inquire with the customer if the connectivity concerns occurred after receiving an operating system update on their phone, or if they have restored their phone data/settings recently.
TTT043217 Rev12018-12-17. Service bulletin. ELECTRICAL SYSTEM:12V/24V/48V BATTERY. TT: Some Customers may complain about a Hybrid Vehicle Battery cooling system warning message. This warning message may appear when the HV Battery cooling system loses efficiency due to debris on the filter and or some object obstructing the air inlet.
TTT0432172018-12-17. Service bulletin. ELECTRICAL SYSTEM:12V/24V/48V BATTERY. TT: Some Customers may complain about a Hybrid Vehicle Battery cooling system warning message. This warning message may appear when the HV Battery cooling system loses efficiency due to debris on the filter and or some object obstructing the air inlet.
T-SB-0279-17_Rev2018-12-17. Service bulletin. ELECTRICAL SYSTEM. TSB: REVISION NOTICE November 13, 2018 Rev2: ? The entire bulletin has been updated. March 16, 2018 Rev1: ? Applicability has been updated to include 2018 model year vehicles. ? The entire bulletin has been updated. Any previous printed versions of this bulletin should be discarded. SUPERSESSION NOTICE The information contained in this bulletin supersedes Service Bulletin Nos. T-SB-0103-16 and T-SB-0337-17. ? The entire bulletin has been updated. Service Bulletin No. T-SB-0103-16 and T-SB-0337-17 are obsolete and any printed versions should be discarded. Be sure to review the entire content of this bulletin before proceeding. Some 2016 ? 2018 model year vehicles equipped with Entune? Audio (version 01013E), Entune? Audio Plus (version 010156 or 01015C), or Entune? Premium Audio (version 010171, 010170, or 01017D) may exhibit one or more of the following conditions: ? Head unit reboots at a specific location ? Abnormal Destination Search app operation ? Rebooting caused by no songs on the USB-connected iPhone ? A one-time reboot after ignition is cycled to ACC-ON ? Audio stays muted after the key is cycled
T-SB-0279-17-Rev2018-12-17. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT:ELECTRICAL:RADIO/TAPE DECK/CD ETC.; EQUIPMENT; EQUIPMENT:ELECTRICAL:NAVIGATIONAL SYSTEM(GLOBAL POSITIONING SYSTEM); EQUIPMENT:ELECTRICAL. TSB: REVISION NOTICE March 16, 2018 Rev1: ? Applicability has been updated to include 2018 model year vehicles. ? The entire bulletin has been updated. Any previous printed versions of this bulletin should be discarded. SUPERSESSION NOTICE The information contained in this bulletin supersedes Service Bulletin No. T-SB-0103-16 and T-SB-0337-17. ? The entire bulletin has been updated. Service Bulletin No. T-SB-0103-16 and T-SB-0337-17 are obsolete and any printed versions should be discarded. Be sure to review the entire content of this bulletin before proceeding. Some 2016 ? 2018 model year vehicles equipped with Entune? Audio (version 01013E), Entune? Audio Plus (version 010156 or 01015C), or Entune? Premium Audio (version 010171, 010170, or 01017D) may exhibit one or more of the following conditions: ? Head unit reboots at a specific location ? Abnormal Destination Search app operation ? Rebooting caused by no songs on the USB-connected iPhone ? A one-time reboot after ignition is cycled to ACC-ON ? Audio stays muted after the key is cycled
T-TT-0442-172018-07-02. Service bulletin. EQUIPMENT; EQUIPMENT:ELECTRICAL; ELECTRICAL SYSTEM. TT: Safety Connect is a vehicle option which requires a subscription fee for the system to be active. The first year of service is provided in the vehicle purchase price. Once the subscription has expired the DCM (Telematics Transceiver) will be in an inactive state. In some instances, a DCM may need to be replaced even though the customer is not using the service.
T-SB-0197-17_Rev2018-06-18. Service bulletin. ELECTRICAL SYSTEM. TSB: REVISION NOTICE May 22, 2018 Rev2: * The Before Delivery section has been updated. May 08, 2018 Rev1: * Applicability has been updated to include 2019 model year Toyota vehicles. Any previous printed versions of this bulletin should be discarded. 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.
T-SB-0197-17_Rev2018-06-18. Service bulletin. ELECTRICAL SYSTEM. TSB: REVISION NOTICE May 08, 2018 Rev1: * Applicability has been updated to include 2019 model year Toyota vehicles. Any previous printed versions of this bulletin should be discarded. 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.
T-SB-0229-12_Rev2018-04-23. Service bulletin. ELECTRICAL SYSTEM. TSB: REVISION NOTICE November 22, 2017 Rev1: ? Applicability has been updated to include 2014 ? 2018 model year vehicles. Any previous printed versions of this bulletin should be discarded. In the event that a Toyota vehicle becomes submerged in water, many components may be physically damaged. Electrical and electronic components, including wiring harnesses, are particularly susceptible to corrosion and subsequent malfunction. Although any flooding can be damaging, salt water flooding elevates the potential for abnormal conditions and may increase risks due to its highly corrosive and conductive nature. Salt residue also continues to corrode and remain conductive even after a vehicle dries. This bulletin is intended to assist with safe handling and inspection of flood damaged vehicles and to provide basic guidance on likely needed repairs.
T-SB-0226-172018-04-02. Service bulletin. 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. A new PDS Check Sheet has been developed for the 2018 model year Avalon/Avalon HV. Some check points have been added, expanded, or clarified. Bulletins are available for items in bold type.
T-SB-0224-172018-04-02. Service bulletin. ELECTRICAL SYSTEM. TSB: Some 2018 model year Avalon and Avalon HV vehicles have had the short pin removed at the assembly plant and temporarily stored in the engine compartment relay block to minimize battery discharge during transportation and storage. Follow the procedures in this bulletin to reinstall the short pin into its original location and confirm that all related Diagnostic Trouble Codes (DTCs) are cleared during Pre-Delivery Service (PDS). NOTE: The short pin is removed ONLY on vehicles going to Hawaii, Puerto Rico, Saipan, Guam and American Samoa.
T-SB-0197-172018-04-02. Service bulletin. ELECTRICAL SYSTEM:12V/24V/48V BATTERY. TSB: Hybrid vehicles are equipped with 2 types of batteries: ? Hybrid Vehicles (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-0195-172018-04-02. Service bulletin. ELECTRICAL SYSTEM. TSB: A battery in a stored vehicle is subject to conditions that can reduce its performance and 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 discharges and/or failed batteries due to lack of maintenance. It is the dealer's responsibility to maintain the specific State-Of-Charge (SOC) of the vehicle's battery while in stock and assure proper SOC at delivery.
T-SB-0337-172018-01-16. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE. TSB: Some customers may complain of the inability to use certain functions of the navigation/infotainment system while the vehicle is in motion. The following software update modifies the system functionality while the vehicle is in motion, improving customer experience. New software is available to address the following: ? Phone keypad unlocked while vehicle is in motion ? Contact list unlocked while vehicle is in motion ? Bluetooth connected phone switching while vehicle is in motion ? Navigation transition improvements (if equipped) ? Revised BT-Audio help pop-up ? Call history list call function improvements ? Reboot after coming out of Reverse ? Errors during phonebook transfer ? Sound settings reset after ignition key cycle ? Surround turns back on after key cycle ?Abnormal operation when listening to FM HD Radio

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