Demon II


Introduction / Identification

The Demon2, pictured above, is the newest in our line of Honda/Acura-friendly P28/P30/P72-compatible technology. Flawless realtime emulation, embedded datalogging, auxiliary ports, 16x calibration storage and encryption.   The Demon II is designed to fit inside only USDM ECUs.   If you have a JDM ECU, be sure to let us know when you order so we can supply an original Demon.  The Demon II combines the features of the Ostrich, Hulog, RTP, and adds its own unique feature set.  The Demon II requires software to specifically support many of its features – not all software support is equal.

Ports and Connectivity

The Demon II uses the same FTDI Device drivers as the rest of the products that we sell.  The Demon II has two USB ports – one standard ‘B’ port that is accessible by cutting the ECU case prior to installation and one mini-B port like prior hardware versions.  Plugging a cable from either of these ports to your PC will allow your PC to communicate with the unit.  Please do NOT plug both USB ports in at the same time.

The Demon II supports additional devices through the black 4 pin add-on header.  Some examples of devices that can be used are the TunerView II, TunerView RD1 and BlueTooth serial modules.  ***IMPORTANT***  The original Demon and Demon II **DO NOT** have the same pinout!  It is entirely possible for damage to occur if incorrectly pinned peripherals are plugged in to the Demon II!  Please make sure you have the correct cables to support the hardware you have.  If you have any doubts, please contact us.

If using the 4-pin TTL with devices such as the Demon/Tunerview interface, TunerView RD1, or Bluetooth, be SURE that the pinout is:
Demon2: 1=Gnd , 2=5v supply , 3=Rx in, 4=Tx out

Software Support

As of 5/5/2014 software support is as follows:

Neptune: Full emulation+data+onboard (stable)
ecTune: Emulation+data (stable)
Crome: Emulation+data (some versions)

Please note that each Demon has a serial number – NepTune and eCtune both license a single copy of the software to a single Demon.  The exact procedure for this is different for each software package.

Datalogging Memory

Demon II units have 4Mbyte (32Mbit) memory.  This is enough for several hours of logging at full speed on all channels, with compression turned on.

Switching Between Software

You can now more easily switch among the different applications using our Config Utility for resetting the state of your Demon.

Indicator Lights

Light behavior on the Demon II is the same as the 1.9+ Demon firmware.

The red LED serves as a hardware status indicator and/or busy light.

  • Red light on solid = not receiving power from the ECU: physical connection issue to ECU
  • Red LED will blink when logging packets are being captured

The green LED is more of a data packet and status indicator light.  It typically behaves as follows:

  • Solid green light when the Demon is powered on and all systems are go but no packets are being received
  • Green light is off when the device is busy OR Demon is powered off
  • Fast green blinks mean the Demon is receiving good datalogging packets from the ECU.


  • Red light onwith USB plugged in means the Demon is NOT receiving power from the ECU.
    • You will only see this condition when the Demon is being powered by USB
    • Check 28 pin socket bridge pins and connection
    • Check ECU CN2 – 4 pin port connection.  This is REQUIRED for proper Demon operation
  • Green light off means no power to ECU.  Red on / green off is expected with no power.
  • No lights at all when USB is plugged in generally is a fault condition.
    • Try removing the Demon from the ECU.  If the Red light comes on, check the chipping job and physical connections between the Demon and the ECU