Not confident with automotive wiring? Have a professional harness builder or tuner do it, or check your work before first power-up. A wiring mistake can damage the ECU, the engine or the car, or start a fire.
Components
| Ref | Kind | Part | Exclude from BOM |
|---|---|---|---|
| MAIN-R | connector | ||
| NEW-BATT | terminal | ||
| OEM-X | connector | ||
| SP-0V | splice | ||
| SP-14V | splice | ||
| SP-GND | splice | ||
| SPEEDUINO-A | connector | ||
| SPEEDUINO-PWR | connector |
Create part
Cut list
Lengths need a layout (0 of 43 routed).
| Wire | From / To | Gauge | Signal |
|---|---|---|---|
| W1 | OEM-X-54 / SP-14V-1 | 0.85 | ECU power (+14V from main relay) |
| W2 | OEM-X-56 / MAIN-R-COIL+ | 0.5 | Ignition switch (terminal 15) |
| W3 | NEW-BATT-1 / MAIN-R-IN | 0.85 | Relay contact input (battery + via main fuse) |
| W4 | MAIN-R-COIL- / SP-GND-1 | 0.5 | Relay coil negative (ECU low-side driver) |
| W5 | MAIN-R-OUT / SPEEDUINO-PWR-12V | 0.85 | Relay contact output (switched +12V bus) |
| W6 | OEM-X-15 / SP-GND-1 | 0.85 | Ground |
| W7 | OEM-X-34 / SP-GND-1 | 0.85 | Ground (output stages) |
| W8 | OEM-X-55 / SP-GND-1 | 0.85 | Ground (ignition) |
| W9 | OEM-X-6 / SP-GND-1 | 0.85 | Ground (injector output stages) |
| W10 | SP-GND-1 / SPEEDUINO-A-10 | 0.85 | Ground |
| W11 | SP-GND-1 / SPEEDUINO-A-9 | 0.85 | Ground |
| W12 | OEM-X-28 / SP-0V-1 | 0.5 | Ground (electronics + sensor shielding) |
| W13 | OEM-X-40 / SP-0V-1 | 0.5 | O2 sensor signal ground |
| W14 | OEM-X-43 / SP-0V-1 | 0.5 | Crank position sensor (-) |
| W15 | OEM-X-44 / SP-0V-1 | 0.5 | Sensor ground (IAT/ECT/TPS) |
| W16 | OEM-X-71 / SP-0V-1 | 0.5 | Knock sensor ground/shield |
| W17 | SP-0V-1 / SPEEDUINO-A-12 | 0.5 | Ground |
| W18 | SP-0V-1 / SPEEDUINO-A-23 | 0.5 | Ground |
| W19 | OEM-X-59 / SPEEDUINO-A-13 | 0.5 | +5V sensor supply |
| W20 | OEM-X-16 / SPEEDUINO-A-25 | 0.5 | Crank position sensor (+) |
| W21 | OEM-X-17 / SPEEDUINO-A-24 | 0.5 | Camshaft position sensor (Hall) |
| W22 | OEM-X-50 / SPEEDUINO-A-7 | 0.5 | Ignition coil cylinder 1 |
| W23 | OEM-X-51 / SPEEDUINO-A-34 | 0.5 | Ignition coil cylinder 2 |
| W24 | OEM-X-52 / SPEEDUINO-A-33 | 0.5 | Ignition coil cylinder 3 |
| W25 | OEM-X-23 / SPEEDUINO-A-8 | 0.5 | Ignition coil cylinder 4 |
| W26 | OEM-X-33 / SPEEDUINO-A-1 | 0.5 | Injector cylinder 1 |
| W27 | OEM-X-32 / SPEEDUINO-A-2 | 0.5 | Injector cylinder 2 |
| W28 | OEM-X-31 / SPEEDUINO-A-3 | 0.5 | Injector cylinder 3 |
| W29 | OEM-X-5 / SPEEDUINO-A-5 | 0.5 | Injector cylinder 4 |
| W30 | OEM-X-3 / SPEEDUINO-A-1 | 0.5 | Injector cylinder 5 |
| W31 | OEM-X-4 / SPEEDUINO-A-2 | 0.5 | Injector cylinder 6 |
| W32 | OEM-X-1 / SPEEDUINO-A-16 | 0.5 | Fuel pump relay control |
| W33 | OEM-X-27 / SPEEDUINO-A-15 | 0.5 | Main relay control |
| W34 | OEM-X-73 / SPEEDUINO-A-22 | 0.5 | Throttle position (TPS) |
| W35 | OEM-X-78 / SPEEDUINO-A-19 | 0.5 | Engine coolant temperature (ECT) |
| W36 | OEM-X-38 / SPEEDUINO-A-36 | 0.5 | O2 sensor heater relay control |
| W37 | OEM-X-2 / SPEEDUINO-A-37 | 0.5 | Idle speed control valve (close winding) |
| W38 | OEM-X-29 / SPEEDUINO-A-35 | 0.5 | Idle speed control valve (open winding) |
| W39 | OEM-X-36 / SPEEDUINO-A-38 | 0.5 | Evap purge solenoid |
| W40 | OEM-X-47 / SPEEDUINO-A-17 | 0.5 | Tachometer output |
| W41 | OEM-X-13 / SPEEDUINO-A-21 | 0.5 | O2 sensor signal |
| W42 | OEM-X-77 / SPEEDUINO-A-20 | 0.5 | Intake air temperature (IAT) |
| W43 | OEM-X-42 / SPEEDUINO-A-14 | 0.5 | Vehicle speed signal |
Bill of materials
No wire parts assigned: 43 wires need a wire part.
| Part number | Manufacturer | Description | Qty | Unit | Unit price | Buy |
|---|---|---|---|---|---|---|
| connector1 line | ||||||
| BMW-E36-DME-CONN | BMW | E36 DME (M3.1/M3.3.1) harness connector | 1 | ea | Mouser ↗Digi-Key ↗Amazon ↗ | |