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Service bulletins for the 2021 Toyota Sienna

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.

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

By type

By component

By trouble code

Only bulletins with component: Engine are shown. Show all

Bulletins, newest first
T-TT-0694-22 Rev22024-07-23. Service bulletin. ENGINE. 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. 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 negative (ground) cable clamps are attached on or around the engine ECU or ECU mounting bracket.
T-PANT-2024-004-2024-04-15. Service bulletin. ENGINE AND ENGINE COOLING; ENGINE AND ENGINE COOLING:ENGINE:OIL/LUBRICATION. This is to advise of various price adjustments that will affect Toyota Genuine Motor Oil and Long Life Coolant, effective March 1, 2024. These products are ordered through the Toyota Complete Maintenance Care (TCMC) website.
22TE09b2024-04-01. Service bulletin. ENGINE AND ENGINE COOLING; HYBRID PROPULSION SYSTEM. TI: TECHNICAL INSTRUCTIONS FOR CUSTOMER SUPPORT PROGRAM 22TE09 HV FLOOR UNDER WIRE HARNESS AND REAR TRACTION MOTOR CABLE CORROSION CERTAIN 2021 ? 2022 MODEL YEAR SIENNA HYBRID
22TE092024-04-01. Service bulletin. ENGINE AND ENGINE COOLING; HYBRID PROPULSION SYSTEM. DP: Although the HV Floor Under Wire Harness and Rear Traction Motor Cable is covered by Toyota?s New Vehicle Limited Warranty for 3 years or 36,000 miles (whichever comes first), we at Toyota care about the customers? ownership experience. Toyota is providing coverage for repairs related to excessive corrosion to the wire harness connections at the Rear Motor Generator. Excessive corrosion can cause AM Radio Static during certain drive cycles, or the vehicle may not start.
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-0702-22 Rev2024-03-18. Service bulletin. ENGINE AND ENGINE COOLING. TT: Some 2020-2022 vehicles equipped with North American Produced (NAP) A25A-FKS/FXS engines may experience an oil leak from the head/valve cover gasket. This issue is currently under investigation.
LSB0065232024-01-29. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL:CRANKCASE (PCV); UNKNOWN OR OTHER. TT: Engine Oil Leak between the Lower Oil Pan and Crank Case
TSB0092232023-12-26. Service bulletin. ENGINE AND ENGINE COOLING. Toyota vehicles equipped with an A25A-FKS or A25A-FXS engine may exhibit reduced engine power and/or a MIL ON condition
T-SB-0083-232023-11-27. Service bulletin. ELECTRICAL SYSTEM:INSTRUMENT PANEL:FUEL GAUGE; ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM):SOFTWARE; ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL. TSB: Some 2021 ? 2022 model year Sienna Hybrid vehicles may exhibit a condition in which the fuel gauge reading changes when the vehicle is driven up or down an incline and left at an angle of up to 15° for five minutes or longer. The combination meter assembly ECU logic has been modified to reduce the possibility of this condition. Follow the Repair Procedure in this bulletin to reprogram the combination meter assembly ECU.
TSB-0033-232023-07-31. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL; FUEL SYSTEM, GASOLINE. TSB: Some 2020 ? 2023 model year Highlander Hybrid and 2021 ? 2023 model year RAV4 Hybrid, RAV4 Prime, Sienna Hybrid, and Venza Hybrid vehicles may exhibit a MIL ON condition with one or both of the following Diagnostic Trouble Codes (DTCs) present: ?P24517F ? Evaporative Emission System Switching Valve Actuator Stuck Off. ?P14502A ? Fuel Tank Pressure Sensor Signal Stuck in Range.
T-TT-0694-222023-06-26. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM). 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. 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
TTT0702222023-05-01. Service bulletin. ENGINE AND ENGINE COOLING. TT: Some 2020-2022 vehicles equipped with North American Produced (NAP) A25A-FKS/FXS engines may experience an oil leak from the head/valve cover gasket. This issue is currently under investigation.
TTT0699222022-10-17. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM):SOFTWARE. TT: Some Model Year 2018-2021 vehicles equipped with A25A-FKS/FXS or M20A-FKS/FXS engines may display the following message ?Engine Maintenance Required Visit Your Dealer? on the combination meter.
TSB011120Rev12022-10-17. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM). TSB: When certain vehicle ECUs are replaced, the ECU security key must be written in order for that ECU to communicate on the vehicle network. The Techstream Software Health Check Results screen has been enhanced to help identify if a replacement ECU requires an ECU security key.
T-TT-0694-22 Rev2022-09-15. Service bulletin. ENGINE AND ENGINE COOLING. 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-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-0031-212021-06-21. Service bulletin. ENGINE; ELECTRICAL SYSTEM. TSB: Some 2021 model year Sienna Hybrid LE vehicles may exhibit a condition of inoperative remote functions from the app or key fob, such as remote engine start or door lock/unlock functions. Registering either, or both, the ?Remote Engine Starter Registration Status? and ?Remote Door Lock Function? may be necessary using Techstream to address this condition. Follow the Repair Procedure in this bulletin to address this condition.
T-SB-0111-202020-12-21. Service bulletin. EQUIPMENT:ELECTRICAL; ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM). TSB: When certain vehicle ECUs are replaced, the ECU security key must be written in order for that ECU to communicate on the vehicle network. The Techstream Software Health Check Results screen has been enhanced to help identify if a replacement ECU requires an ECU security key. Follow the procedures in this bulletin to write the ECU security key to the replacement ECU.

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