Suzuki K6a Engine Ecu Pinout May 2026
Because the factory K6A ECUs are becoming rare and are notoriously difficult to tune for high horsepower, many owners switch to standalone ECUs like the Megasquirt/Speeduino or Link G4X.
When wiring a standalone:
| Pin | Signal | Description | |------|---------------------------|-------------------------------------| | B1 | Fuel pump relay control | ECU grounds to turn on fuel pump | | B2 | Check engine light (MIL) | Ground to illuminate CEL | | B3 | Main relay control | ECU grounds main EFI relay | | B4 | Cooling fan relay 1 | Fan low speed | | B5 | Cooling fan relay 2 | Fan high speed (if equipped) | | B6 | A/C compressor clutch relay | Engages AC compressor | | B7 | Wastegate solenoid (turbo) | Boost control duty | | B8 | O2 heater ground | Heater circuit ground | | B9 | Injector common +12V | From main relay (via resistor pack if external) | | B10 | +12V ignition switched | IG power (engine running/cranking) | | B11 | +12V main relay | Same as A13 (redundant) | | B12 | Power ground | Heavy ground for injectors/coils | | B13-24 | (may be unused or model-specific) | EGR temp, oil pressure switch, etc. | suzuki k6a engine ecu pinout
| Pin | Wire Color | Function | Notes | | :--- | :--- | :--- | :--- | | B1 | Green/Red | TPS (Throttle Position) Signal | 0.5V (closed) to 4.5V (WOT) | | B2 | Red | TPS Sensor 5V Reference | +5V regulated | | B3 | Green/Black | MAP Sensor (Manifold Absolute Pressure) | Frequency based or 0-5V | | B4 | Black/Blue | MAP/BARO Sensor Ground | 0V | | B6 | White/Red | IAT (Intake Air Temp) | Resistance (2k Ohm cold) | | B7 | Black/Red | ECT (Engine Coolant Temp) | Resistance (200-300 Ohm hot) | | B10 | Yellow/Red | Camshaft Position Sensor (CMP) | Hall effect (0-5V square) | | B11 | Blue/White | Cam Sensor Power | 12V or 5V depending on year | | B15 | Green/Yellow | IACV (Idle Air Control Valve) - Coil 1 | Stepper motor / PWM | | B16 | Green/Blue | IACV - Coil 2 | Stepper motor / PWM | | B17 | Green/Black | IACV - Coil 3 | Stepper motor / PWM | | B18 | Green/Orange | IACV - Coil 4 | Stepper motor / PWM | | B22 | Pink/Black | O2 Sensor (Lambda) Signal | 0.1V (lean) to 0.9V (rich) | | B25 | Orange | Vehicle Speed Sensor (VSS) | 5V pulse frequency | | B30 | Light Green/Red | Check Engine Light (MIL) | Ground output to illuminate | | B31 | Blue | Diagnostic Switch (DLC Pin for code read) | Ground to enter diagnostic mode | | B35 | Purple | Starter Signal (SW) | 12V while cranking |
Disclaimer: Wire colors vary by chassis (Alto vs Wagon R). Always back-probe to verify before cutting. Because the factory K6A ECUs are becoming rare
| Sensor | Pin | Voltage | | :--- | :--- | :--- | | TPS Signal | A6 | 0.45 - 0.55V | | MAP (NA) | A7 | 3.8 - 4.0V | | MAP (Turbo at idle) | A7 | 1.2 - 1.5V | | ECT (Cold @ 20°C) | A21 | 2.5 - 3.0V | | O2 Sensor | A24 | 0.2 - 0.8V (fluctuating) |
If you are modifying beyond a simple exhaust and boost controller, the factory K6A ECU becomes a problem. It does not like bigger injectors (it sees them as a "leak") and has aggressive fuel cut on overboost. | Pin | Wire Color | Function |
For serious builds (150hp+), most tuners switch to a Link ECU, Haltech Elite 550, or MaxxECU. When doing so, the pinout above becomes your roadmap for repinning the factory harness.