SM3+ ECU! 

Our leading SM3 a full replacement for the original EFI System  with a very strong feature set, state of the art electronics designed to withstand some of the toughest conditions and still provide enough I/O to precisely control and tune your engine over a high speed on-board bluetooth or USB connection!

Our SM3 is smart, it will automatic revert to master USB connection as soon as the USB cable is plugged in! Without USB connection it will switch to Bluetooth(if installed).

It's based around the MegaSquirt3 firmware but with refind electronics and a custom software .INI-file for our SM3, making it much more user/install friendly!

We believe and stand 200% behind our product, that we offer 3years factory return warranty!

General SM3+


IP65 OEM-look Aluminium Casing

Temperature range

AECQ100 Automotive graded

Reverse battery protection

Yes, internal

Operating voltage


Operating current (ECU)

< 0.5A or 2-4A with LSU4.9 sensor(s) connected

Weight (g)



1x Automotive connector


USB or Bleutooth

Outputs SM3+

Injector outputs

6 protected outputs 3A, low side (Low&High Impedance supported)

Ignition outputs

6 outputs 12A(peak) (passive&active coils supported)

Aux outputs

13 protected outputs 2A, low side


2 short circuit protected


Yes onboard

Input SM3+


15  10 Analog inputs 10Bits 0-5V, 5 Digital inputs or additional inputs over CAN

EGT inputs

1 K-Type thermocouple

Knock sensor inputs


Oxygen inputs

2  wideband 0-5V or narrowband

Trigger inputs

2 both inputs Hall ,VR or optical compatible



Flex Fuel


Sensors Inputs SM3+

Temperature sensors

IAT, CLT, Oil temperature,EGT, etc

Pressure sensors

MAP, Onboard realtime BARO, Oil pressure, Fuel pressure, AC pressure sensor,EBP,etc

Oxygen sensors

LSU 4.9 (Onboard controller) and/or  (TinyO2) (CANbus) 3rd party controllers


Vehicle speed sensor (VSS)

Fueling Outputs SM3+


6 (Full-sequential) or 12 (batched fire)

Battery compensation

User defined

Fueling strategies

VE based speed density, Alpha-N, ITB

Air charge temp.

Based on IAT and CLT

VE table

4 tables 16×16 (Load x RPM), resolution of 0.1

Individual cylinder trim


Staged injection


Additional correction

EGT correction (per cylinder), BARO, TPS vs MAP, TPS vs RPM, Warmup, Nitrous, LC, ALS, ASE, Fuel pressure, Knock sensor

Lambda based real time correction

Lambda/AFR target table

Acc. / Deceleration enrichment


Ignition Outputs SM3+

Ignition outputs

6 for passive and active coils (Full-sequential) or 12 in wasted spark

Supported trigger Patterns


Ignition angle table

4 tables 16×16 (Load x RPM), resolution of 0.1 Deg

Per cylinder trim


Dwell time battery compensation

User defined

Odd fire compatibility

Application dependent

Additional correction

CLT, IAT, TPS vs MAP, Nitrous, Idle, Knock sensor, LC, Pit limiter, ALS, Flat shift, Timers, Acc. enrichment

Knock Sensing Features SM3+



Resonant frequency range



Ignition event driven (per cylinder), knock window, user defined gain


Ignition retard and/or fuel enrichment (per cylinder), dashboard indication

Idle Control Output SM3+

Control type

PWM solenoids (2,3 wires)

Control strategy

Open / Close loop cranking and warm-up duty

VE correction



AC clutch, coolant fan, analog input, ignition angle based

Boost Control Features SM3+

Boost ref and target tables

2 sets 8×8 (TPS vs RPM)

Control strategies

Open / Closed loop (PID based)



Traction Control Features SM3+

TC strategy

VSS % slip,Perfect run(RPM), Switch input

Torque reduction

Spark retard or cut, Fuel cut, Boost cut

Sensitivity control

Software or switch input

Variable Valve Timing Features SM3+

Supported systems

VVTi, MiVec, VANOS, Double Vanos,VarioCam etc

Number of camshafts


Control strategy

PID based closed loop, CAM angle target tables 8×8

Flex Fueling Features SM3+

Ethanol content measurement


Fuel temperature measurement


Tables blending

VE, IGN, Lambda/AFR, Boost, Cranking fuel, ASE, Warmup

Fuel temperature PW correction


Racing Features SM3+



Shift light

Per gear shift light up to 6 gears

Launch control

Yes,variable,2 or 3 step

Flat Shift

Yes VSS and/or Switch

Pit limiter


Rolling anti lag


Sequential Shift Cut

Yes, Input or Auto-shift by RPM, Solenoid output

Engine Protection Features SM3+

Fail safe values for critical sensors


Dashboard indication of failures

Yes, user defined

Over temperature engine protection

Yes, user defined

Low oil pressure protection

Yes, user defined

Fuel pressure protection

Yes, user defined

High exhaust temperature

Alarm, per cylinder fuel trim, boost limit

CANbus Feature SM3+

CAN standard

250, 500, 1000 kBps 11 or 29 bits

Supported CAN Dashes


Supported CAN streams

Multiple User definable

Other Features SM3+ 

Unused injection outputs can be used as AUX output


Unused ignition outputs can be used as AUX output


Output functions

Fuel pump, coolant fan, Programmable outputs, nitrous control, PWM 3D table outputs, AC clutch, main relay, speedometer, tachometer etc


Fuel, Ignition, Boost, 2 closed loop programmable outputs



Built in trigger scope

Tooth,trigger,composite, sync diagnostic

Data Logging

Onboard 1Gb with RTC (real time clock, battery maintained)

Included products:

  • "Wire-in" connector + 90 crimp terminals
  • User Manual
  • Stickers & goodies
  • 1.5m Pre-crimped USB cable

All ECU’s are build to order and fully tested before shipping out within 48hours.

USB Driver
SM3 ECU r1 User Manual (Obsoleted)
SM3 ECU r1.2 User Manual(Obsoleted)
*ECU Beta custom ini file
SM3+ ECU r1.3 User Manual(Obsoleted)
SM3+ ECU r1.4 User Manual(Obsoleted)
SM3+ ECU r1.5 User Manual(Obsoleted)
SM3 Pinout Schematic
SM3+ ECU r1.5b User Manual

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  • Product Code: SM3+ ECU
  • Reward Points: 5
  • Availability: 4
  • 659.99€
  • 639.99€

  • Ex Tax: 528.92€
  • Price in reward points: 665

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