SECU-3i Engine Management System ECU

SECU-3 Engine Management SystemSECU-3i Engine Management System ECU is latest author’s development. Allows to fully control SI engine and incorporates all necessary devices in one metallic enclosure.

Control of fuel injection, ignition, electric fuel pump, canister purge valve, starter relay, cooling fan, gas doser, automatic choke and other auxiliary devices. Can be used either as full function EMS or simply as ignition controller (e.g. on carburetor).




  • 5 ignition channels (can be expanded up to 6 by means of 5-th injection channel)
  • 5 injection channels (can be expanded up to 8 by means of 5-th ignition channel plus two outputs, used to control of stepper IAC valve)
  • 4 and 5 injection channels can be configured as high-side outputs (for driving of idle cut-off valve, power valve etc)
  • Air conditioner’s clutch control
  • Oxygen sensor’s heating control
  • All outputs have over current, over voltage and over temperature protection
  • USB interface with digital isolation!
  • Embedded Bluetooth module for wireless communication with PC, notebook or smart phone (since 2019 BK3231 chips)
  • On-board power drivers for high resistance injectors
  • Two outputs have optional high-side configurations
  • On-board power driver for ignition coils
  • Stepper motor driver (for IAC actuator, gas doser or automatic choke)
  • Driver for PWM IAC (single or double winding)
  • Universal programmable outputs
  • Embedded 250 kPa MAP (MPX4250AP)
  • Output for low or high voltage tachometer
  • Inputs for connecting of two knock sensors.
  • By default unit configured as following: 5 injection channels, 5 ignition channels, stepper and PWM IAC

SECU-3i Engine Management System diagram

When ordering:

1. Specify, how many cylinders your engine is (1, 2, 3, 4, 5, 6, 8)

2. Specify which ignition configuration you plan to use (HV distributor, wasted spark, full sequential)

3. Specify which injection configuration you plan to use (simultaneous, semi-sequential, full sequential etc)

More photos:

secu-3i_unit_front1SECU-3 Engine Management Systemsecu-3i_tb_pcb_anglesecu-3i_bb_pcb_anglesecu-3i_bb_pcb_topsecu-3i_tb_pcb_top

Some wiring diagram examples (more examples are here):
SECU-3i unit 4x4 wiring example