Spedometer Problem

[byf41]

I have a 2003 FXDL I bought new . Occasionally the speedometer will read exactly twice the actual speed . As soon as you key It off and re start It will read normally . The dealer looked at It a few times under warranty years ago and replaced the sensor but problem Is still there occasionally and seems to be getting more frequent . Connections at sensor terminal are clean and tight . Suggestions welcome .

[rigidthumper]

I remembered we had that issue on 99-01 speedos if the engine was started immediately after key on,  before the speedo reset was complete- I thought that problem went away by 2003, but maybe not. By waiting 2 seconds after key on, never saw that again.

[les]

You mention that the speed sensor has been replaced years ago.  How long was the speedo solid/fixed after they did that?

[byf41]

It was never fixed and has happened occasionally since new . Last week It did It twice . Hadnt happened for months so I just thought I would Inquire . I like rigidthumpers explination , I will try to make a conscious effort to wait before lighting It off and see what happens . I thought It may have been due to where the reluctor wheel happens to stop , maybe on a gap or certain area of the wheel ?

[Pirsch Fire Wagon]

Ensure the Data Wire from the ECM to the Spedo and pins are acceptable. models one or the other is defective, loose, or not making a good connection which eliminated the problem

I have found in the earlier (pre-07 and especially pre OB5 ECMs] have the issue.

And almost always fix's the issue.

I have also found the easiest way to identify is using DT-II or Centurion Pro the Speedometer will return "Module Not Found" occasionally for the Spedo.

[mtrhead269]

Just run one of the many GPS speedo options

[byf41]

Well I made sure to wait several seconds before start up and It did It again the other day so I guess that theory didn't work out . Where would I find the ecm on my 03 FXDL and which wire are we talking about that may cause the Issue ? I have a service manual but couldn't find that Information .

[jty]

ECM sends the speed to the speedometer over a digital protocol, among all the other information, thus not likely to be a wiring problem between ecm and speedo. I would suggest the issue is in either speedo or ecm.