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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 control module are shown. Show all

Bulletins, newest first
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.
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
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-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.