| Pin | Wire Color | Function | |-----|------------|----------| | A1 | B-Y | +12V Battery (BATT) | | A2 | B | Ground (E1) | | A3 | R-B | +12V IG SW (IGSW) | | B1 | G-R | Injector #1 | | C1 | W-B | Check Engine Light | | C5 | B-O | OBD-II (ISO 9141 K-Line) |
While specific diagrams vary, many Toyota 89661 series ECUs share standardized pin abbreviations and basic power configurations: toyota 89661 ecu pinout
On older ECUs (pre-2003), connectors are labeled E5 , E6 , E7 . On newer ones, they are A , B , C , D . | Pin | Wire Color | Function |
Below are typical pinout configurations for some well-known Toyota 89661 units: 89661-12250 (Corolla 4A-GE "Bigport"): Common Toyota 89661 Variations
| Pin | Function | Wire Color (typical) | |-----|----------|----------------------| | A1 | Injector #1 | Red or Light Green | | A2 | Injector #2 | Yellow or Light Green | | A3 | Injector #3 | Blue or Light Green | | A4 | Injector #4 | White or Light Green | | A5 | Ignition coil #1 | Black/Red | | A6 | Ignition coil #2 | Black/Red | | A7 | Ignition coil #3 | Black/Red | | A8 | Ignition coil #4 | Black/Red | | A9 | EGR vacuum solenoid | Red/White | | A10 | Fuel pump relay control | Blue/Red or Green/Red | | A11 | Main relay control | Yellow/Black | | A12 | +12V battery backup (constant) | White/Red | | A13 | Ground (ECU power) | Brown/White | | A14 | Ground (ECU power) | Brown/White | | A15 | +12V from main relay (switched) | Black/Yellow | | A16 | +12V from main relay (switched) | Black/Yellow | | A17 | O2 heater (front) | Black/White | | A18 | O2 heater (rear) | Black/White | | A19 | Idle air control (IAC) – open | Red/White | | A20 | Idle air control (IAC) – close | Red/Black | | A21 | VVT solenoid (if equipped) | Yellow/Black | | A22 | Cooling fan relay | Green/Black |
: Common issues like leaking capacitors in older 89661 modules (frequent in 1990s models like the Lexus LS400 or Toyota Celsior) require opening the unit and understanding its internal layout. Common Toyota 89661 Variations