DIYPNP Stepper Driver Assembly

The N52 and D56 adapter boards both have extra circuitry for the stepper valves found on many Toyota, Mitsubishi, and GM engines. 

Stepper Control

Stepper control with a MicroSquirt module is supported in the latest V3.0.3 MS2/Extra builds. You cannot run a stepper and sequential injection at the same time.

1. Install resistors R1A through R4A at the edge of the board.
2. Install the stepper driver IC, U1A, with the notched end pointing to the left edge of the board.
3. Install capacitors C1A through C3A.

The stepper IAC circuit has ten jumpers on a header on the far left of the adapter board. Here is how to connect these jumpers.

1. PT6 and PT7 connect to the PT6 and PT7 terminals on the main board.

2. PIB connects to the PIB4 terminal on the main board.

3. The 5 volt connection connects to the 5 volt output pin on the main board.

4. You can connect the 12 volt pin to either a 12 volt terminal on the main board or a 12 volt source from the ECU connector.

5. The GND pin must be grounded to a power (not sensor) ground for the IAC to work.

6. Pins 1A and 1B connect to opposite ends of one coil on the IAC valve, and pins 2A and 2B connect to the other coil. If we have an application specific write up available for your vehicle, we will provide specific wiring details for this if possible.