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This part does not have vehicle specific fitment. Please contact us if you need fitment assistance.

AEM EMS 4 Engine Management System

AEM EMS 4 Engine Management System-A1
AEM EMS 4 Engine Management System-A2
Images may be for reference only

AEM EMS 4 Engine Management System

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Price: $844.38 ($236.43 off)
$607.95 & Free Shipping

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Monday-Friday: 9am-4pm MST


AEM's EMS-4 Universal Standalone Programmable Engine Management System is the ideal standalone Engine Management System for modified Powersports and four-cylinder race car applications. The EMS-4 was created using AEM's powerful Series 2 hardware and includes all of its advanced features without the unneeded ancillary components.

If you have modified your four-cylinder Powersports application beyond the factory ECU's ability to control engine operation, or have a 4-cylinder race vehicle that does not require some of the advanced hardware features of an AEM Series 2 Plug & Play System, AEM's EMS-4 provides complete engine control for the maximum power and reliability.

AEM's EMS-4 provides complete engine control for small engines with up to 4 cylinders. The unit includes a 36-pin connetor that is specifically designed to operate in harsh environments. It is completely sealed and weather/shock proof, allowing it to be mounted anywhere. The EMS-4 works with MAG or HALL crank inputs and can directly drive smart coils or an external ignitor such as AEM's 4-Channel Coil Driver

  • 4 Saturated Injector Outputs (8 ohm minimum, High Impedance Only)
  • 4 Coil Triggers 0-5V Falling Edge Fire (Do not connect to coil primary)

  • Timing Sensor Inputs:
  • 1 VR (Mag) Cam Input
  • 1 VR (Mag) Crank Input
  • 1 Hall VSS Input
  • 1 Hall Crank Input
  • 1 Hall Cam Input

  • Inputs/Outputs:
  • 4 GPIO - 1.5A Low Side Output / 0-5V Analog Input / Switch Input
  • 4 GPIO - 1.5A Low Side Output / 0-5V Analog Input / PWM Output
  • 1 O2 Sensor Input 0-5V Analog
  • 1 Knock Sensor Input Programmable
  • 1 Throttle Position Sensor Input 0-5V
  • 1 Manifold Pressure Sensor Input 0-5V
  • 1 Coolant Temperature Sensor Input 0-5V
  • 1 Inlet Air Temperature Sensor Input 0-5V
  • 1 Sensor Ground
  • 1 5 Volt Reference

  • Communication:
  • USB comms
  • Communication cables included
  • Fully enabled editing/logging software included
  • CAN bus equipped with Programmable Send / Receive
  • CAN data stream output

  • DATA Acquisition
  • 8MB Internal data logging
  • 125 Hz Maximum internal logging rate (per channel)
  • PC logging
  • Data analysis using AEMLog

  • Functions and Features:
  • User adjustable knock sensor center frequency
  • Individual cylinder ignition trims
  • Individual cylinder fuel trims
  • High/Low speed fuel pump support
  • All channels/maps/tuning options unlocked
  • Boost control
  • Groundspeed based boost target
  • Nitrous injection
  • Staged injection
  • Ground speed limiting
  • Rate of Acceleration Control
  • Overrun boost enhancement (anti-lag)
  • Gear change ignition cut (shift-without-lift)
  • Password protected calibrations
  • Fuel & Ignition rev limiters
  • "In cockpit" global fuel trim capability
  • Gear dependent shift light
  • Evap/Purge function
  • Software definable "virtual" switch inputs
  • EGT Based fuel trims (additional hardware needed)
  • No Maximum boost limit

  • Physical Dimensions:
  • Length: 120 mm
  • Width: 114 mm
  • Height: 35 mm
  • Finish: Black

  • Not legal for sale or use in California on any pollution controlled motor vehicles. See for state by state emissions requirements.

    WARNING: This product may contain chemicals known to the State of California to cause cancer or birth defects.


    Brand: AEM Electronics
    Part Number: 30-6905
    UPC: 840879021665
    CARB Approved: No

    Vehicle Fitment

    This part does not have vehicle specific fitment

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