(Corolla, Camry, RAV4). Use only as a starting point— verify every pin .
Because "89661" covers thousands of different ECUs spanning from the 1980s to the present day, A 89661 ECU from a 1994 Supra 2JZ-GTE looks and wires completely differently than a 89661 ECU from a 2005 Camry 2AZ-FE. 2. Common Connector Generations
Below is a concise, general overview for the Toyota 89661 ECU connector family (commonly used in many Toyota models for engine/ECM and immobilizer-related connections). Connector pinouts can vary by model year, engine type, and region—use this only as a starting reference and verify against the vehicle’s factory service manual or wiring diagrams for the specific VIN.
Switched 12V power supply from the EFI main relay.
Sensor ground return path. Never ground these to the chassis; they must loop back directly to the sensors to prevent electrical noise. toyota 89661 ecu pinout
Ignition Switch signal. Tells the ECU that the key has been turned to the "ON" position.
For older OBD1 units, shorting the TE1 and E1 pins causes the check engine light ( W pin) to flash error codes. For OBD2 units, wire the SIL (SDL) pin to Pin 7 of an OBD2 diagnostic port to communicate with a handheld scanner. Precautions When Handling Toyota ECUs
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Look for the on the ECU case label:
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1JZ-GTE VVTi, 2JZ-GTE VVTi, 3S-GE Beams, 1ZZ-FE, 2AZ-FE.
Pins are significantly smaller to accommodate complex variable valve timing and early electronic throttle controls (ETCS-i).
If you need to power up an 89661 ECU on a workbench to pull codes or flash a chip, you only need to connect a few vital pins. (Corolla, Camry, RAV4)
Example: 89661-2F210 (2002 Camry 2.4L) ^^^^^^ This suffix is critical
Camshaft position sensor signals used to determine cylinder sequencing. VTA / VTA2: Throttle Position Sensor (TPS) signal voltage.
Ultimate Toyota 89661 ECU Pinout Guide: Wire Your Engine Right