AEM MEFi-4 Harness

AEM MEFi-4 Harness


MEFI-4 Plug & Play Adapter Harness with Expansion Port

Once you have determined which Series 3 Infinity ECU will best support your MEFI-4 equipped engine, you will need to purchase the Infinity MEFI-4 Plug & Play adapter harness (PN 30-3829). This Harness delivers seamless conversion from dated MEFI platform to state-of-the-art Infinity ECU, with boost control, nitrous control, launch control, engine protection and more built in!

The MEFI-4 Plug & Play Adapter Harness includes an AEMnet connector for communication with other AEMnet enabled devices and an auxiliary connector with a High Performance DTM-Style 12P connector for adding common aftermarket sensors including fuel pressure, air inlet temperature, MAP, oil temperature and ethanol content sensor. The expansion port also includes a sensor ground, 5v reference, 12v power from relay and high side output for activating a relay or solenoid, a low side output for boost control and analog inputs for mode switch and no-lift shift.


The Infinity 308 (PN 30-7113) features two different injector types and two different coil outputs that support three different types of fuel and ignition configurations.

For throttle-body-injected (TBI) and GM multi-port fuel injected V8s the Infinity 308 includes a single direct-drive ignition coil output to work with a distributor and a single coil, and 2 peak & hold injector drivers that can drive up to four high-impedance injectors each. Other port injected and single-coil distributed V8 engines like the Ford Windsor can be controlled using the Infinity 308’s 8 high impedance injector divers and single direct-drive coil output.

For the Chevy LS, the Infinity 308 has 8 high impedance injector drivers and 8 “smart” coil outputs to drive a coil-near-plug ignition system.


The Infinity 358 (PN 30-7114) is designed to control 2V and 4V Ford Modular engines, late-model Dodge Hemi engines and other late-model, individual direct-drive “dumb” coil V8 engines with port injection using 8 high impedance injectors.

Optional Accessories

The Series 3 Infinity ECUs do not include on-board Lambda sensor controller for wideband air/fuel ratio. If you do not have a wideband air/fuel controller we recommend our X-Series Wideband Controllers (Inline or Gauge).

The Infinity Series 3 ECUs include a basic engine history feature. If you require robust data logging capability we recommend our AQ-1 Data Logger, which can be connected to the Infinity through a simple AEMnet CAN bus connection.

200MHz Processor and Real Time Operating System
Late model vehicle ECU’s all run on faster processors. The Infinity ECU is built around a latest-generation 32 bit floating point 200MHz automotive processor and Real Time Operating System (RTOS), which is capable of processing 400 MIPS (millions of instructions per second). By comparison, common competitive systems typically use 20MHz to 50MHz processors. To our knowledge, the Infinity ECU currently has the fastest processing speed of any aftermarket Motorsports ECU available. This allows the Infinity to do more, faster, in a more stable programming environment.

  • The Infinity’s 200MHz processor and RTOS makes the Infinity more responsive, for a better driving experience

  • The Infinity’s 200MHz processor and RTOS allows for more accurate ignition timing, which enables an engine to create more power

  • The Infinity’s faster processor allows it to perform more computational features with no sacrifice in processing performance

  • The Infinity’s RTOS ensures strategic processing with optimized load balancing. This means that tuning one feature will not affect the performance of another feature

  • Fuel Injection control via airflow model-based (VE) tuning

  • Full ignition control

  • Closed loop AFR feedback

  • ECU Set Up Wizard simplifies start up

  • Flex fuel compatible

  • Multiple boost control strategies

  • Nitrous control

  • Map switching

  • Dual knock sensing circuits

  • Engine history

  • Outputs to 3rd party dashes and data loggers

  • Integrated engine protection strategies

  • Sealed enclosure and IP67 rated comms ports

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