HSD-4 wire colors
| Function |
Connects to |
HSD-4 wire |
| Input A |
ECU or TCU |
Yellow |
| Output A |
Solenoid |
White |
| Input B |
ECU or TCU |
Orange |
| Output B |
Solenoid |
Pink |
| Input C |
ECU or TCU |
Dark green |
| Output C |
Solenoid |
Light green |
| Input D |
ECU or TCU |
Blue |
| Output D |
Solenoid |
Purple |
| Power |
Switched 12V |
Red |
The red wires should all be grouped together and connected to a single fuse to 12 volt switched power. The fuse should be rated for the total current draw of all outputs being used, up to a maximum of 30 amps.
ECU connections
The inputs need a ground signal to trigger their outputs. Here are what outputs you can use to trigger the HSD-4 high side driver with DIYAutoTune engine or transmission management.
MS3-Pro: High current, PWM, injector, or tach outputs
MSPNP Gen 2: Output 1, output 2, boost, or tach outputs
MicroSquirt (transmission control): Shift solenoid, TCC, or EPC outputs
MicroSquirt (engine control): ALED, WLED, FIDLE, or tach outputs
MS3X: Mid current, tach, or injector outputs
MS1 or MS2: Relay control outputs or FIDLE (MS2 only)
GPIO board: General purpose, PWM, or high current outputs
