Installing an American ECU on a European or Aussie bike

[kaldek]

If you lose all the keys to an Australian or European bike, you are faced with an expensive prospect to get the bike running again, as the ECU is coded to transponders in the keys (via H.I.S.S). It is possible these days to have your old ECU reprogrammed via some folks on eBay, but what if you find an American ECU somewhere much cheaper?

Unfortunately Honda expected that nefarious folks might try this when stealing motorcycles, so they modified the wiring harness. American ECUs won't work on European or Aussie wiring harnesses - or will they?

I mapped all the pins on both my Aussie wiring harness and American wiring harness that I happen to have lying around. It turns out that the only difference between the two harnesses is that American systems use two power feeds into the ECU rather than one. Both feeds are the black/white wire, which is the +12V signal from the engine stop relay. Anyone familiar with the 6th-gen wiring will know this is the circuit used to power pretty much the entire FI system (PAIR solenoid, EVAP solenoid, airbox flapper solenoid, injectors, coils, fuel pump relay).

So in order to get your USA ECU to work on a Euro bike, you need to remove a pin and wire from somewhere else on your ECU connector plug, and move it to the pin where the additional power feed is needed. This pin is on the grey connector, pin #16. Once you have inserted your relocated pin into this hole it will clip into place, and you can then splice the wire into the black/white wire from the engine stop relay. The wire you relocate can be any of the following pins from the grey connector, as they are not used on the USA model ECU:

• Pin #1 - Blue wire
  
• Pin #12 - White/Red wire
  
• Pin #14 - Pink Wire
  
• Pin #32 - Orange/Blue wire
  

Note that this process is specific to 2006 and newer models. Older units may "just work" or may also require relocation of a pin.

WARNING: You cannot put an ECU from a 2002-2005 bike on a 2006+ model bike without also replacing the wiring harness, as the ECU hardware and connectors are totally different.

[dogman]

You are the Guru my friend.

So does it still run rich on cold start?

[kaldek]

You are the Guru my friend.

So does it still run rich on cold start?

Yeah, but testing continues. I'm waiting on the diagnostic tool from HealTech so I can see what the ECU thinks is going on. I'm also going to do valve clearance checks and some other mechanical checks to make sure the problem is not being caused by some form of issue affecting engine vacuum.