TSB T-TT-0784-25 — Toyota Service bulletin
T-TT-0784-25 is a service bulletin on file with NHTSA for the Toyota Prius, 2019–2025 model years, filed and re-filed as 2 documents. A TSB is factory repair guidance, not a recall — the repair is not automatically free.
What the bulletin says. Some ECUs can set a DTC that is common with other ECUs. This can lead to accidental use of the wrong repair manual when diagnosing these type of DTCs.
NHTSA's own summary of the document, quoted from the public manufacturer-communications file.
Vehicles and model years T-TT-0784-25 names
Every document filed under T-TT-0784-25
Manufacturers re-issue a bulletin as the repair changes, and file separate copies for technicians and for owners. All of them carry the same number.
| Document ID | Filed | Type |
|---|---|---|
| T-TT-0784-25 Rev1 | June 17, 2025 | Service bulletin |
| T-TT-0784-25 | June 13, 2025 | Service bulletin |
What T-TT-0784-25 covers
Engine — the component vocabulary NHTSA files this communication under.
Questions buyers ask
What is TSB T-TT-0784-25?
T-TT-0784-25 is a service bulletin filed with NHTSA by Toyota, covering the Toyota Prius across the 2019–2025 model years. NHTSA's summary reads: Some ECUs can set a DTC that is common with other ECUs. This can lead to accidental use of the wrong repair manual when diagnosing these type of DTCs.
Which vehicles does T-TT-0784-25 cover?
NHTSA's file names Toyota Prius (2019–2025). A bulletin number can be re-issued against more vehicles later, so check the model-year list on this page against your own.
Is TSB T-TT-0784-25 a recall, and is the repair free?
No. T-TT-0784-25 is repair guidance the manufacturer sent its dealers, not a safety defect finding. You pay for the work unless the vehicle is still under warranty. Recall repairs, by contrast, are always free.
How do I get the full text of T-TT-0784-25?
Take the document ID to a dealer's service desk, or search NHTSA's manufacturer-communications records. This page carries every document ID filed under T-TT-0784-25, its date, and NHTSA's own summary from the public file.
Every number on this page is a count of records in the federal complaint, recall, and investigation files published by NHTSA's Office of Defects Investigation. This page lists only what NHTSA's manufacturer-communications file records under T-TT-0784-25. Check any specific vehicle's open recalls by VIN at nhtsa.gov/recalls.