MS3 Pro for NB

MS3 Pro Assembly instructions PCB V4.0 NB revision 2
MS3 Pro Assembly instructions PCB V5.0 NB
MS3 Pro Assembly instructions PCB V5.1 NB

I designed this board for the 99-05 MX5 NB(FL), to be used with the DIY Autotune MS3 Pro module.

Usage is very simple, get the MS3 Pro Module, get this PCB and bolt the module to it.  Install inside the oem case, ultimately ending up with a “MSPNP-PRO”.

Final cost is about the same as DIY built to the same level as the ms3pro but it has several advantages:
The difficulty in troubleshooting a non-standard build. Every problem requires an overview of your assembly first.
The robustness of the ms3pro is far better than a diy box.
Future proof HW setup, change the car and only change the harness.

More pictures

You just plug in the MS3 Pro module and install the board inside the stock ecu case.

For clarity, the pcb is made for a standard MS3 Pro module, thus no modifications are necessary to the MS3 Pro or its firmware.

This board fits all NB versions, US, JDM and Euro market.

There are 2 boards available, the older V3.2 and the newer V4, they are nearly identical except that the V3.5 has a couple of extra circuits.

Board specifications:

  • usb connector
  • pullup resistors for all in- and outputs
  • proto area with gnd, 5V and 12V
  • 3 stage shift light
  • RS232 to TTL (for internal bluetooth module)
  • CAN port
  • map sensor MPX-4250AP
  • 2nd map sensor for baro correction (MPX-4250AP or the MPXH6400A equivalent in SMD footprint)
  • Bluetooth or WiFi
  • 1 EGT circuit
  • optional JBperf TinyIOx module
  • optional accelerometer
  • 3 VR conditioners circuits for ABS to Vss (for traction control and launch control)
  • 2 Hi spec VR conditioners
  • 4 ADC conditioners
  • 2 active low input circuits

All unused in- and outputs can be brought out to the mazda connector in case you have extra functions.
All information is on the front and back silk to make it easier to do modifications. It’s just a matter of adding a resistor or a jumper.


V4 pcb only: $35 + $9 shipment [wp_cart_button name=”MS3 Pro 99-05 baseboard V4 non registered shipping” price=”25.00″ shipping=”5″]


  • basic parts $15 (USB connector, pullup resistors, header pins)
  • oem Mazda connector for 99-00 ($29)
  • oem Mazda connector for 01-05 ($29)
  • alternator circuit ($12)
  • map sensor MPX4250AP ($28)
  • baro sensor (MPX4250AP, 1 resistor, 2 capacitors) ($29)
  • baro sensor SMD (MPXH6400A, 1 resistor , 2 capacitors) ($24)
  • internal Bluetooth module pre-programmed ($24)
  • WiFi module pre-programmed ($29)
  • registered shipping ($8 extra shipping cost)

To order, contact me .


Remark to self:

On MegaSquirt, there’s only 2 different concurrent frequencies allowed across all pwm outputs.  On the Pro Module they are grouped like this:

Group A
High Current Out 1
High Current Out 2
High Current Out 3

Group B
PWM (idle) out 1
PWM out 2
PWM out 3

What this sharing means is that Idle and VVT must use the same frequency.
By moving VVT to an output of group A, this allows for a different frequency.


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