| Pin | Wire Color | Signal Name | Function | | :-- | :--- | :--- | :--- | | C1 | R-B (Red-Black) | L4 | Transfer Case Low Range Switch | | C2 | G-W (Green-White) | OD1 | Overdrive On/Off Switch (Automatic) | | C3 | B (Black) | OD2 | Overdrive Indicator Light | | C4 | Y (Yellow) | KNK | Knock Sensor Signal (if equipped – rare on 1KZ) | | C5 | L (Blue) | CRU | Cruise Control Main Switch | | C6 | G-R (Green-Red) | C-CS | Cruise Control Set/Coast Signal | | C7 | R-W (Red-White) | C-RS | Cruise Control Resume/Accel Signal | | C8 | – | N/C | Not Connected | | C9 | BR (Brown) | MREL | EFI Main Relay Control (ECU grounds to turn on relay) | | C10 | B (Black) | SPD | Speed Sensor (secondary input for cruise) | | C11 | R (Red) | +BM | Backup power for cruise control | | C12 | W-B (White-Black) | E3 | ECU ground for cruise section |
⚠️ Pin arrangement can vary slightly by vehicle and model year. Always verify with a wiring diagram for your specific chassis. 1kz ecu pinout