Hey, have a problem with a bike I’ve been troubleshooting for 2 days now. I’ve searched all over the internet, have the electrical diagnostic manual and run some tests and continue to only come up with this code u1255 under Sp in diagnostic mode.

The bike is a 2007 Fatboy, I have no turn signals, no front brake light, and no start. The fuel pump primes when in the run position. I’ve checked all fuses, they are good. The battery is good. The bike was running a few days ago.

Now this code states it’s a serial data error under the speedometer module diagnostics. My question: Is this code for a bad speedometer or a bad TSM/HFSM?

Any help or direction is greatly appreciated. I’m leaning forward the TSM/HFSM because of the no turn signals.

 

Also, my red key light stays on whenever I turn the off/run switch to run, and no other work has been done to alter anything recently. Internal wiring for bars was done several years ago, but the bike has run fine since!

Once again, thanks for the replies and ride safe!!

 

Does the key icon blink or stay on all the time?

This is from a 2007 Softail owner's manual-

The illuminated key icon in the speedometer face indicates the status of the Harley-Davidson Smart Security System.
Armed: A key icon that blinks approximately every 3 seconds indicates that the system is armed.
Disarmed: After the ignition/headlamp switch is turned to IGNITION and the system disarms, the key icon will remain illuminated for approximately four seconds and then turn off.
Service: A key icon that remains illuminated longer than four seconds indicates that service of the module is required.

Have you replaced the Key Fob battery in the last year?

Replace the key fob battery every year.
Slowly turn a thin blade in the thumbnail slot (1) on the side of the fob to separate the two halves.
Remove the battery (2) and discard.
Install a new battery (Panasonic 2032 or equivalent) with the positive (+) side down.
Align the two halves of the fob and snap together.

 

 

UPDATE:

Ok, so I did my research and troubleshooting and it was in fact a bad TSM. On this bike, there is no security, so the red key light displays and stays lit after the 4 second initial ignition start when there are DTC codes existing, hence the bad TSM. Replaced the TSM with new and all is good.

Ride safe!!

 

Hello, i know it's been an old thread but i hope you're still there cause i'm having the same problem. Mine is 05' iltra classic efi with no fob as well. Suddenly the red key light appear on the speedometer, and check engine light doesn't come up and both speedoemeter n rpm gauge are not working. Did you experience the same symptoms?

 

With mine the bike wouldn't start, and there were other things not working as well, like the turn signals and lights. I used the electrical diagnostics and troubleshooted, determining it was a bad TSM, which controls a lot of the functions on the bike. I would recommend starting that with a good multimeter. Also, make sure you load test your battery, many a time people start assuming other stuff. It's an easy fix, so eliminate the easy things first and make sure you're solid.

Ride safe!!

 

Hello, turns out it was only a loosen LG/V cable which was the serial data cable from the harness into the socket of my speedometer harness. All the tsm etc works well, it's the cable that transfer data from the ecm to instrument cluster that was splited up so speedo didn't receive any data. Thanks for ur reply, stay safe and ride safe always!

 

From your post this all started after the Halo light was unhooked and the spark plug wires where changed. Everything was fine before this stuff was changed.

So its been my experience that you have to retrace your steps back to when all of this started. Also the fact that the bike isn't showing a code rules out some stuff. Not sure what ignition system you have in the bike, but you have to match it with the right spark plug wires or it can cause some issues. I don't know if that year of bike had the Delphi ignition system or not as they were fussy if you used anything but the stock HD plugs for that ignition system.

I know not much of an answer, but it seems that it was something you and your buddy changed.