Ks150

I have been fixing a rebuilder 2011 F150 with the 3.5. It was a front end collision and damaged the PCM (powertrain control module). I bought a PCM out of a salvage vehicle. It was all the right numbers and everything. Got the truck all finished up and went to the dealer to have it reprogramed. They got it programed and it started and ran with no problems. The only problem we are having is we can't get the speedometer to read correct. The truck that the PCM came out of had 3.73 gears and the truck its in now has 3.31. We changed the programing in the BCM (Body Control module) to say it has 3.31 gears and correct tires however it didn't help the problem. The dealer said that the PCM has nothing to do with the speedometer reading it all comes from the BCM, however the PCM is the only thing that was changed to effect this. Has anyone had any expeience with putting a used PCM in? The reading on the speedometer is off just right on 9-10% at any speed. Any help is greatly appreciated.

sjavera

I am having this exact same problem after a gear swap. 2011 ecoboost I went from 3.15 to 3.73 with a larger tire and the speedo is off about 10%. The dealer says the same thing ... They set the tire size and gear ratio. Did you figure your issue out? Thanks!

dajohu

Can either of you try different tire settings to get it to read right?

I got larger tires so my speedo was off about 1-2mph@60 so I decided to get it updated when I got my last tune. Well with it "corrected" it is off 3+mph@60 now. If I would have known it was going to do that I would have left it alone lol.

I planned to just fix it by playing with the RPM settings, basically lying about the tire size until it reads as close as I can get it.