Denso · petrol · 1998–2026
Toyota ECU 89661-08 xxx — Sienna engine ECU
Sienna: 89661-08120 (2005 3.3), 89661-08440 (2016–2018 3.5). 2021+ hybrids carry Gen3 units.
Models fitted with 89661-08
Prefix-to-application pairing checked against published parts data on 2026-10-14.
Clone the 89661-08 ECU — $350 flat
Mail your original and a donor with the same full part number. VIN, immobilizer data, coding and adaptations are copied across on the bench, typically within 24 hours of arrival. Factory immobilizer stays on.
Toyota / Lexus / Scion engine ECU cloneOn-car software step — remote Techstream, $250
Some cars still want an on-car step after a module swap — an ECU communication ID registration on a smart-key car, a calibration update, or a key registration. Plug a J2534 pass-thru interface into the car and we run the factory Techstream software on it from our bench — no dealer visit. The same session covers programming after any other Toyota or Lexus module replacement.
Book the Toyota / Lexus remote sessionFrequently asked questions
What is Toyota ECU part number 89661-08?
89661-08 is the model code of a Toyota / Lexus / Scion engine control unit in the Sienna engine ECU family (Denso), common on 1998–2026 petrol cars. Sienna: 89661-08120 (2005 3.3), 89661-08440 (2016–2018 3.5). 2021+ hybrids carry Gen3 units. The rest of the number selects the exact calibration.
Which models use a 89661-08 ECU?
In the US: Sienna XL10 through XL40 (1998–2026). Always confirm with the label — the same model year can carry a different family on another engine or build.
Can you clone a 89661-08 ECU?
Yes. Mail your original 89661-08 unit and a donor with the same full part number and we copy your VIN, immobilizer data, coding and adaptations onto the donor for $350 flat, typically within 24 hours of arrival, immobilizer intact. If the car then asks for an on-car step, the remote Techstream session over J2534 is $250.