The OEM ECU (Engine Control Unit) 89661‑42670 for the 2001‑2005 Toyota RAV4 2.0 VVTI (engine code 1AZ‑FE) is the factory engine computer that controls fuel injection, ignition timing, emissions, and immobiliser functions; when replacing, you often need programming or VIN/security data transfer to match keys/immobiliser, and the part is sold in “locked”, “unlocked”, or “plug‑and‑play” variants. 

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