Wednesday, June 22, 2022

Guidelines for Crome

These guidelines are only for ECUs tuned with a Crome ROM editor (otherwise see general compatiblity guidelines). When using Crome tuned ECUs (P06, P08, P27, P28, P30, P75 etc.), compatibility with Hondash depends on the following points:
  1. Crome version and configuration
  2. pcb jumpers
  3. correctly wired OBD2A/B to OBD1 conversion harness (if applicable)

Version and configuration

  • "classic" or "standard" version - compatible (Plugins » Enhancements » Quick Datalogger + RTP must not be added to the map (ROM) when flashing a chip, as the plugin overrides the original communication implementation)
  • "gold" version - NOT compatible (due to the RTP being injected into the ROM by default without any option for disabling it)


  • jumper J12 (or J4) must be located on the PCB, usually as a resistor (zero ohm resistor ). If it was removed or cut by you or previous car owner or person tuning your ECU, replace the missing component with a simple wire (see pictures).
    • P28, P30 (non-JDM rectangular ECU): J12 jumper
      hondash J12 jumper 1
      J12 - missing jumper replaced with a wire
      hondash J12 jumper 2
      J12 - factory stock original zero ohm resistor / jumper
    • P30 (JDM square ECU): J4 jumper
      hondash J4 jumper
      J4 - missing jumper replaced with a wire
  • jumper J1 must be connected in order to use an external modified map (ROM) stored on a EEPROM chip.
    However if the pcb jumper J12 (or J4) is connected as described above and you're still not able to get Hondash to communicate (due to used incompatible ROM) and you want to restore compatibility with Hondash at any cost, just remove jumper J1. Main processor should fall back to using an internal stock map (ROM) instead of external one stored on EEPROM chip. Some users also install a switch instead of J1 jumper to switch between internal(stock) and external(modified) maps on the fly.
    Please be advised, if your engine is heavily modified (high lift cams, turbo, etc.) it's not recommended to run it on a stock map outside of low engine load conditions (idle, part throttle), take actions at your own risk.
    If you had to cut the J1 jumper to get Hondash to work, it proves that the flashed ROM is incompatible and you must reflash the chip again using a correct Crome version and configuration!
    hondash J1 jumper
    J1 jumper

OBD2A/B to OBD1 conversion

Direct wiring

  • in case you need to wire the scanner directly due to missing diagnostic connector use the folowing wiring reference