: Understanding Toyota's shorthand is critical for troubleshooting. For instance, BATT is constant power, IGSW is ignition switch power, and E1 is the main ground. A detailed Toyota ECU Pinout Abbreviations Guide is available for identifying signal types.
| 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 | toyota 89661 ecu pinout
You can find power, ground, and 5V reference. But you cannot identify injector drivers, ignition outputs, or O2 heater grounds without the correct pinout document. Injector drivers look like ground until the ECU pulses them. | Pin | Function | Signal Type |