Speedometer problem
Thread Starter
Catch22
Joined: Aug 2009
Posts: 19
Likes: 1
From: Massachusetts
Speedometer problem
2005 F150 SCrew with 5.4 - While highway driving I noticed my speedo was a little off compared to my GPS speed. Speedo said I was going 75 while the GPS said 60. I thought that was kind of strange but didn't think too much of it. I got to my location and the truck sat for 1 hour. Once I got back in the truck I noticed the speedo was reading 40 mph while in park. The needle moves smoothly when both accelerating or slowing down - but its always off based on where it started. Once stopped, It does not always go back to 40 mph either. Where it ends up when at rest varies - and it has yet to go back to zero. I don't even know where to start. Any help would be appreciated - I've been told there is no cable so I might be looking at a computer module somewhere
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Thread Starter
Catch22
Joined: Aug 2009
Posts: 19
Likes: 1
From: Massachusetts
Now its way off
My speedometer eventually went to zero while at rest where it worked fine for a week. Today I look down and the Speedometer says I'm going 90 when I'm doing around 25. At rest its reading 65 mph while the truck is either running or no key in the ignition at all. I am going to try and disconnect the battery this weekend and post the results. Is there a speed sensor that feeds the data for the speedometer to display? If so, where is it located?
Senior Member
Joined: Aug 2009
Posts: 363
Likes: 8
good luck with these buy its definatly something electrical by the sound, i would look into a reflash or pulling the ground wire for a bit, when you start truck up again after reconnecting the battery, let it run for fifteen minutes at idol as this allows computer to calibrate itself and run thru self check tests.
