i ran the diag test, code : p0603

according to the sticky, this corresponds to "ECM EEPROM Memory Error"

quick google search and EEPROM = Electronically erasable programmable read-only memory

so my question is, do I have to replace the entire ECM?

or can this be fixed at a shop? usually with computers ROM can't be changed...but the "electronically erasable programmable" part must mean something in this case.

 

Before buying a new ECM, I’d try to program it several times. Cycle the bike power and try again. Even disconnect the negative battery terminal for a while and try it again, if that don’t work, have the dealer look at it with their diagnostic tool. You should be able to unplug it and un-bolt it and take it to the dealer.

Else, the EEPROM is “likely” ball soldered to the printed circuit board for cost savings, but maybe not, it used to be common to insert EEPROMs into a socket for easy removal, re-program or replace. I’ve never taken an ECM apart, put being as small as it is, it’s likely soldered directly to the circuit board, which means it’s really hard to replace. Plus even if you could replace it, you’d have to find out what the specs are for this specific EEPROM and then try to find one that meets the exact same specs, which would include physical size, pin out, read voltage, program voltage, addressing and timing, etc., etc. Getting to know how Harley works, my guess that this is an integrated proprietary chip that’s probably virtually impossible to replace. You might be looking at needing a new ECM.

 

Is the code current? Does the bike start?

 

yeah the code is current and the bike runs fine

just played around with it, cleared it and disconnected the battery. error came back immediately.

probably going to take the ecm to the shop tomorrow

thanks for the help

 

Veritas: Assuming you're still a member of this site, did you ever resolve the P0603 code issue? I've had this same code persisting on my 07 Sportster 1200 since last year. Initially, battery went dead, thought I needed a new battery but turns out I had a bad voltage regulator. Mechanic replaced the regulator, battery now charges fine, but the P0603 persists. Bike seems to run fine, but I'd really like to figure out why the code persists and fix the issue. Thx for any help.

 

probably so.
in the auto world where you have thousands of vehicles, the computers are usually rebuilt but with small numbers like hd, probably not so. i would check with a dealer to see if a reman unit is even offered.
most auto stuff is mil spec'd. the components are directly attached. the ecu is probably potted so a look-see for bad board joints will be a bear. the newer components cannot be hand soldered as a lot is going to rear of chip solder pads, less cost and less space needed. as was brought out, hd may house mark the components.
you can have the chip run through diagnostics to see if all the data addresses are good. if the read/write line is snafu'd, it is toast.
the ecu uses memory to crunch data that is constantly changing and using the outcome to control the machine so if a data address cannot be accessed, the error code will flag. the ecu probably can lose some data storage and work but will take longer and eventually have issues. in a round-about way, it is like a computer hard drive.

 

So why were you playing with it in the first place ?

 

That error is no bueno, the Harley ECM stores the configuration inside the microcontroller eeprom, that kind of memory have a limited storage time, usually around 20 years depending on the model and the storage temperature, and on top of that each eeprom page have a limited number of times that it can be erased and reprogrammed, once that number is reached the page becomes read only and cannot be written anymore.