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 |
|---|---|---|---|
| MICROSQUIRT-A | connector | ||
| OEM-1 | connector | ||
| OEM-3 | connector | ||
| OEM-4 | connector | ||
| SP-0V | splice | ||
| SP-14V | splice | ||
| SP-GND | splice |
Create part
Cut list
Lengths need a layout (0 of 38 routed).
| Wire | From / To | Gauge | Signal |
|---|---|---|---|
| W1 | OEM-4-B / SP-14V-1 | 0.85 | ECU power +12V (main relay) |
| W2 | SP-14V-1 / MICROSQUIRT-A-1 | 0.85 | +12V In |
| W3 | OEM-4-A / SP-GND-1 | 0.85 | Chassis ground |
| W4 | OEM-4-C / SP-GND-1 | 0.85 | Chassis ground |
| W5 | OEM-4-D / SP-GND-1 | 0.85 | Chassis ground |
| W6 | OEM-4-K / SP-GND-1 | 0.85 | Chassis ground |
| W7 | SP-GND-1 / MICROSQUIRT-A-22 | 0.85 | POWER GROUND |
| W8 | SP-GND-1 / MICROSQUIRT-A-23 | 0.85 | POWER GROUND |
| W9 | OEM-3-O / SP-0V-1 | 0.5 | Sensor ground |
| W10 | OEM-4-H / SP-0V-1 | 0.5 | Crank pickup timing ground (CKP gnd) |
| W11 | SP-0V-1 / MICROSQUIRT-A-18 | 0.5 | Sensor Ground |
| W12 | SP-0V-1 / MICROSQUIRT-A-19 | 0.5 | Serial Ground |
| W13 | SP-0V-1 / MICROSQUIRT-A-20 | 0.5 | Sensor Ground |
| W14 | OEM-3-I / MICROSQUIRT-A-28 | 0.5 | +5V sensor reference |
| W15 | OEM-4-E / MICROSQUIRT-A-32 | 0.5 | Crank position (CKP) sensor |
| W16 | OEM-4-G / MICROSQUIRT-A-4 | 0.5 | CAS SGC (cam sync) |
| W17 | OEM-4-F / MICROSQUIRT-A-21 | 0.5 | CAS SGT (cam trigger) |
| W18 | OEM-4-N / MICROSQUIRT-A-11 | 0.5 | Ignition coil trigger (cyl 1&4) |
| W19 | OEM-4-R / MICROSQUIRT-A-12 | 0.5 | Ignition coil trigger (cyl 2&3) |
| W20 | OEM-4-U / MICROSQUIRT-A-9 | 0.5 | Injector 1 (cyl 1) |
| W21 | OEM-4-V / MICROSQUIRT-A-10 | 0.5 | Injector 2 (cyl 2) |
| W22 | OEM-4-W / MICROSQUIRT-A-9 | 0.5 | Injector 3 (cyl 3) |
| W23 | OEM-4-X / MICROSQUIRT-A-10 | 0.5 | Injector 4 (cyl 4) |
| W24 | OEM-3-B / MICROSQUIRT-A-5 | 0.5 | MAF sensor input |
| W25 | OEM-3-F / MICROSQUIRT-A-27 | 0.5 | Throttle position (TPS) |
| W26 | OEM-3-G / MICROSQUIRT-A-25 | 0.5 | Engine coolant temp (CLT) |
| W27 | OEM-1-A / MICROSQUIRT-A-8 | 0.5 | Cooling fan relay (low-side) |
| W28 | OEM-1-B / MICROSQUIRT-A-16 | 0.5 | A/C condenser fan relay |
| W29 | OEM-1-G / MICROSQUIRT-A-17 | 0.5 | A/C clutch relay |
| W30 | OEM-1-U / MICROSQUIRT-A-7 | 0.5 | Fuel pump relay (low-side) |
| W31 | OEM-4-L / MICROSQUIRT-A-35 | 0.5 | Tachometer output |
| W32 | OEM-3-H / MICROSQUIRT-A-24 | 0.5 | EGR boost sensor |
| W33 | OEM-3-N / MICROSQUIRT-A-29 | 0.5 | EGR boost sensor (2nd channel) |
| W34 | OEM-3-C / MICROSQUIRT-A-34 | 0.5 | Front O2 sensor input |
| W35 | OEM-3-K / MICROSQUIRT-A-26 | 0.5 | Intake air temp (IAT) |
| W36 | OEM-1-M / MICROSQUIRT-A-30 | 0.5 | Vehicle speed sensor (VSS) |
| W37 | OEM-1-C / MICROSQUIRT-A-31 | 0.5 | Starter input (12V while cranking) |
| W38 | OEM-1-K / MICROSQUIRT-A-6 | 0.5 | A/C pressure switch (A/C request) |
Bill of materials
No parts in this harness.