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ECM Flash

90FXRS

90FXRS

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What might cause the ecm to return to a previous setting? Does this make any sense? Flash it and it goes back to the previous setting when you cycle the ignition.
 
Guess I should have put a little more info out there. Bike has an issue with stalling at an idle. Cleaned the iac, as I did with mine, still does it. Good friend works for a dealer and came over. Plugged in the lappy and the vin is not recognized and neither is the speedo. This is with Harley dealer's service laptop.

Flashed the ecm, which I don't think is the stock one. The part number on the back is not listed in parts catalog for the bike. Afterwards when we checked it.......still not seeing the vin or speedo.

Correct me if I'm wrong......if the ecm does not recognize the speedo, when you slow down it has no idea how fast you're going so the injection system might flood the motor.

Ecm replacement for the old guy?
 
a couple of minutes is more than enough, from memory the early efi bikes arent speed dependant, the 07? and up has the speedo linked in. bit of a hard one
 
90FXRS said:
Correct me if I'm wrong......if the ecm does not recognize the speedo, when you slow down it has no idea how fast you're going so the injection system might flood the motor.
Click to expand...

That will not happen. The speed of the bike is irrelevant to injector pulse width. Pulse width & frequency is a function of engine load and RPM. Stalling at idle can be caused by a number of things. For it to be a "bad" ECM would be very remote.
 
Here's the results. Changed the ecm to a new unit, part number 32534-05C. The old powercommander is not compatible with newer ecms. Called them and they weren't sure if they would play together or not. Tried a couple of things and the result is a new ecm and sert. Put it on the dyno......110 horse and 109 torque. Rode the bike for about 75 miles.....never missed a lick. Took it back into the shop and the system is seeing everything as it should. Vin, speedo are recognized and no errors in the system.
 
Check the old ECM part number, your new one is a rev C...so hardware mods were likely added, if old one was 05_ rev. Suppose the dealer might have a service bulletin why the rev change, but it would be safe to assume that was the problem.

The new ECM version (p/n 32534-05C is at least the 4th version (-05, -05A, -05B preceeded it).

CROSS REFERENCE dated January 2004:

p/n 32772-01 Use on ’01 to ’04 Big Twin EFI ECM’s (when obsolete - use 32534-05)
 
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