I've searched the net endlessly trying to find someone that has had this issue. Nothing seems to add up to what I have going on, so any help with this would be greatly appreciated. So here's the scoop. I have a 2008 GT with the 4.6 standard trans...I blew my rear end and bought a new rebuild axle with 3.55 gears. After getting my car back I now have no speedo or odometer or cruise control. After a few miles I get a DTE ODO data error, low fuel and eventually a P0720 code. I've already checked the wiring, all fuses, and replaced the OSS on the trans. The axle I bought was off of a newer model so they had to reuse the wheel sensors off of my 2008 axle. Would that cause an issue. I'm stumped at this point so any ideas would be welcome.

 

Since that code has to do with the transmission end (transmission output shaft) maybe you bumped something during the axle exchange.

 

I've looked over everything...wiring etc and even bought and replaced the output shaft sensor. Wiring all looks perfect and the sensor is now brand new. I'm not sure anything else could really be bumped. The only thing they should have touched besides the axle would be the swapping of the wheel sensors. Mine was a 2008 and this new axle is a 2012. The new axle had a different style sensor so the old ones had to be used on the new axle. The axle builder said it was a non issue. I'm at a loss here.

 

The sensors on the axle are for the ABS so that wouldn't have anything to do with your issues.

 

How did the shop account for the change in gear from 3.31 to 3.55, reflashed the PCM? To do that you need a handheld programmer like an SCT X3 or Diablo Sport.

They could have done it with a mechanical compensatory device but those are usually junk in newer cars.

If they flashed it, they need to reflash it because something got corrupted the first time. It happens sometimes.

 

I actually have and sct x3 and thought of that myself. I put in the 3.55 ratio into my custom tune and save it to the pcm, but the issue still resumed. I will try it again tomorrow, maybe for some reason it didn't take the first time around, but wouldn't the speedometer and odometer still at least work, just be a bit off with the original 3.31 programming?

 

Who did you get the tunes from? Maybe have them rewrite them to include the 3.55 by default. It shouldn't cost anything and then you'll know for certain, that it's not the problem.

I sometimes fiddle with the timing settings on my 91P tune (American Muscle Tunes) because during the summer it gets so hot here that if I don't , i get pinging. So i retard the base by 2 degrees and also retard the 2000-4000 and 4000-6000 bands by an additional two. Once it cools off like now, I reprogram the car to run the unedited tunes.

I panicked once when I got a PCM error on startup and the car shut down on me. Reprogrammed it again and it was fine.