Standalone Engine Management SEM201 Based on MS3x

$USD 295.0

Out of stock

SKU: sem201 Category:


Standalone engine management system based on Megasquirt MS3x Processor and firmware with enhanced inputs and output ports. It is capable of controlling sequential injection on engines up to 8 cylinders, or semi-sequential up to 16 cylinders, combined with direct fire ignition for engines up to 8 cylinders or wasted spark ignition on engines up to 16 cylinders. Can be connected as fully standalone ECU or as piggyback and share the sensor reading with the stock ECU as it has differential trigger inputs, The 4 bar internal MAP sensor can read up to 44psi of boost, Programmable knocking detector circuit can be used to adjust the ignition timing,  5V ref voltage, and internal switch to pull up resistor. The CAN bus facilitate the communication with SPTRONICS O2 sensor wideband controller and EGT amplifier for more accurate reading. It has dedicated inputs (Crank, CAM, CLT, IAT, MAP, TPS, O2 and knocking) and 9 low side outputs to drive injectors or any solenoid valve. 2 dedicated ignition outputs and 6 ignition outputs shared with inputs. Bluetooth connectivity, SD card loggin, RTC.


  • 2x Deffrential Trigger inputs (Hall, VR and Opto).
  • 9x High impedance low side output  3A each to drive injectors or to be used for auxiliary outputs.
  • 8x Ignition output 1A max (5V or 12V)/ shared with inputs
  • 2x Analog inputs shared with Ignition Output 3 and 4.
  • 2x Digital inputs shared with Ignition outputs 5 and 6.
  • 2x selectable input between analog or digital shared with ignition outputs 7 and 8.
  • 4x dedicated analog input, coolant temperature, Intake air temperature,  O2 sensor, Throttle position.
  • Programmable knocking input ./ shared with analog input.
  • 4 bar built in MAP sensor.
  • Fully compatible with MSextra Software
  • Fuel Table 16×16
  • Ignition Table 16×16
  • Connected to computer through USB.
  • 1.5 meter harness + connectors
  • Supports CAN Bus
  • Bluetooth connectivity.
  • SD card logging.
  • Can be connected as standalone or piggyback
  • Dimensions  95mm x 104mm


Fuel table size 16×16
Fuel table resolution 0.1%
rpm resolution 1 rpm
Accel enrichment Simple (TPS,MAP), Enhanced (wall-wetting)
Spark table size 16×16
Advance resolution (commanded) 0.1 deg
Injector phasing Bank/batch fire,Semi sequential or 4cyl sequential
Injector timing Timed within crank pulses or timed for start, middle, end of injection pulse
Injector trim Mapped trim table per cylinder when running sequential.
Spark trim Not adjustable
Distributor spark Y
Trigger return dizzy Y
Simple wheel decoding Y
Every tooth wheel decoding Y*
Wasted spark Y
Coil on plug Y
Dual dizzy Y
Cam / 2nd tach input Y
Number of spark outputs 6
Rotary trailing Y
HEI7, GMDIS Y (with bypass control)
Oddfire wheel decoder Y
Oddfire dizzy Y
Neon/420A Y
36-1+1 Y
36-2-2-2 Y
Subaru 6/7 Y
IAW Weber-Marelli Y
Mitsubushi 6g72 Y
4/1 CAS Y
4G63 (Miata) Y
99-00 Miata Y
Renix 44-2-2 Y
Twin trigger (aka. dual spark) Y
Suzuki Swift Y
Suzuki Vitara Y (Untested!)
Daihatsu 3 cyl Y (Unproven)
Daihatsu 4cyl Y (Untested!)
Rover K Series 36-1-1 Y
Rover K Series 36-1-1-1-1 Y
Rover K Series 36-2-2 Y (Untested!)
Honda VTR1000 12-3 Y
Chrysler 2.2/2.5 Y
GM 7X native Y
Nissan 360 tooth CAS N/P>
Load methods SD, AN, map/baro (load%), ITB
Load blending Y
Load tables 2
Staged injection Y
Over-run fuel cut Y
Tachometer output Y
Launch Control/flat shift Y
Spark cut rev limit Y
Dwell duty% Y
Dwell battery correction table of %ages
Cranking pulsewidth table of %ages
Alternate cranking injection Y
Specific cranking advance, dwell Y
Fixed timing for setup Y
Test mode Pump, Inj, Coils, Idle
Closed loop idle control Y
Boost control Y (open or closed loop with PID control)
Nitrous control Y (2 stage)
Knock sensor (software) Y
Realtime barometric correction Y
Water Injection N
Table Switching Y
Configurable outputs Y
AFR target tables Y
Dual fuel tables (per bank) Y
Synchronous sensor sampling Y
Built in tooth/trigger loggers Y (tooth, trigger, composite, sync-errror)


Download Tunerstudio

Download USB driver

Download installation manual

About the author


  1. Hi, I am really interested in getting one of your standalone ecus I am debating between SEM 103, 201 and 301, which I plan to use on one of my turbocharged 2rz-fe ( I have two and eventually will be getting a second ecu, depending on how it works), I would like to know if you guys would guide me somehow through installation and ways to make my truck run and race with it , at least if not to tune it completely help me get a basic tune for it, I’ve been reading a lot and I have been looking at your product and I am getting convinced of buying it, I might as well influence on people by recommending cuz I belong to many social media groups.

    1. Hi, We can help and guide you through wiring and the basic setting to get the base map and the engine running, but we can not do the tune online for you.

      1. Hey guys ! In my search for an ECU for one of my current project I got recommend your ones as couple of followers have them .
        I’m just wondering in which ecu would suit what I need .
        It’s a Volvo 945 with a B230 originally turbo , 4cyl 8v 2.300cc
        Goes to have only a turbo GT3582 ,manifold ,600/650 injectors, 3″ intercooler and 3″ exhaust. I want the ECU to remove the MAF and run everything.
        Probably I’m interested in ethanol too but not sure yet .
        Also interested in antilag, launch , flatshift . No big thing , more like a weekend car to do track days and show car.
        I’m also a knoob on electronics , what ECU can you recommend me ?
        Cheers ✌️

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