While there isn't a single "official" review for a generic (as "89661" is a prefix used for hundreds of different Engine Control Units), technical feedback from automotive forums and technician platforms like JustAnswer consistently highlights its utility for DIY repairs and engine swaps. Overview of the Toyota 89661 Series
Ignition Feedback signal sent to the ECU to confirm a spark occurred (the ECU will cut fuel if it doesn't see this). #10, #20, #30: Injector drive signals. VC / VCC: 5V reference power for sensors (TPS, MAP). PIM / VG: Manifold pressure or Mass Airflow signal. THW: Water temperature sensor. THA: Intake air temperature sensor. OX / HT: Oxygen sensor signal and heater circuit. 4. How to Read a Toyota Pinout Diagram toyota 89661 ecu pinout
| Pin | Function | Signal Type | Typical Color | |-----|----------|-------------|----------------| | B1 | Engine coolant temp (ECT) | 0-5V analog | Green/Yellow | | B2 | Intake air temp (IAT) | 0-5V analog | Yellow/Black | | B3 | Throttle position sensor (TPS) signal | 0-5V variable | Gray/Red | | B4 | TPS reference voltage (5V) | +5V | Light Green | | B5 | TPS ground | Sensor ground | Brown/White | | B6 | MAP/MAF signal | Frequency or 0-5V | Pink/Black | | B7 | MAP/MAF ground | Sensor ground | White/Black | | B8 | Knock sensor | AC signal | White | | B9 | Camshaft position (CMP) | Digital | Yellow/Blue | | B10 | Crankshaft position (CKP) | AC or digital | Black/White | | B11 | Sensor ground common | 0V reference | Brown | | B12 | +5V sensor supply | +5V | Light Green/Red | | B13 | Oxygen sensor front (signal) | 0-1V | White | | B14 | Oxygen sensor rear (signal) | 0-1V | White/Black | | B15 | VSS (vehicle speed) | Square wave | Violet/White | | B16 | Neutral safety switch (auto) | Ground or 12V | Blue/Yellow | | B17 | Power steering pressure switch | Ground | Red/Black | | B18 | A/C request signal | 12V | Blue/Black | | B19 | A/C amplifier feedback | 0-5V | Yellow/Green | | B20 | Electrical load signal | 12V | Red/Yellow | | B21 | Starter signal (STA) | 12V crank | Black/White | | B22 | Battery voltage sense | 12V | White/Red | While there isn't a single "official" review for