When the engine starts cutting out under load, refuses to start when hot, or logs a hard-to-read check engine light, the first place a professional mechanic turns is the .
No start but cranking? Check Pin B1 (crank sensor) resistance should be 1.6–2.1 kΩ. If open, the ECU never fires the injectors. Connector C – Outputs & Communications (16P) | Pin | Wire Color | Function | Notes | |------|-------------|---------------------------|------------------------------| | C1 | Black | TC terminal (check engine light) | Switched ground – illuminates when fault exists | | C2 | White | Tachometer output | 12V square wave (diesel tach) | | C3 | Green | AC idle-up request | 12V when AC compressor on | | C5 | Orange | Diagnostic (SIL) | 9600 baud for Toyota scanner | | C6 | Blue/Red | EGR vacuum switching valve (VSV) | 12V control | | C9 | Yellow | Immobilizer communication (if equipped) | Serial data to transponder amp | | C10 | Brown/Red | Fuel heater relay | 12V below 5°C | | C12 | Pink | Idle-up VSV for power steering | 12V at steering load | 1kz ecu pinout
Always start with the pinout. Never throw parts at a diesel ECU until you verify voltage, ground, and signal at the pins. Part 8: Wire Color Variations (Prado vs. Hiace vs. Surf) Toyota changed wire colors slightly by model: When the engine starts cutting out under load,