I have a 2003 Expedition Eddie Buaer with approx. 105,000 miles on it. Yesterday we went to pass an Amish buggy, my husband nailed it and the trans kicked down. However, the O/D off light started blinking and has been since. He has a friend who owns an auto shop that scanned it using his SnapOn scanner. It came back with a P0172 Transmission Fluid Temperature Sensor cucuit input low code. It runs and shifts fine. The only thing out of the ordinary is that it is eating gas like crazy now and every once in a while it will shift hard low when coming to a stop. The trans fluid doesn't look or smell burnt. It was a tiny bit low, so we put about a half a quart of Trans fluid in it. Any suggestions would be gratly appreciated.

 

Go get the code read again as that Pxxxx code you posted has nothing to do with the transmission.

 

Sorry. I transposed my numbers. It was P0712.

 

Can I continue to drive it like this? It is our only car right now since our other car died over the weekend.

 

Probably. The only adverse condition I can see in the manual is that you'll get firmer shifts.

 

What do we need to do to repair it?

 

No-one has any DYI fixes for this problem? I would rather we fix it at home then take ti somewhere.

 

I found this on a Ford F-150 forum with the same code and the solution:

Update...
After doing research on-line with the codes I believed that the codes were indicative to the sensor needing to be replaced. I contacted the original mechanic who performed the transmission fluid change and who also detected the codes. I explained to him that the Ford dealer wanted me to pay 1200.00 to tear apart my transmission just too fully diagnose the issue, and NOT fix it. I told him that I believe he was correct when he originally thought it was the sensor and I asked to perform the replacement of the sensor. I took the truck into him and he dropped the transmission pan/fluid and replaced the sensor. After replacing the sensor and putting new fluid back in the transmission, all is working just fine.
So the bottom line here with my issue was NOT a bad transmission like the mechanics at the FORD dealer in SanJuan Capistrano CA. suggested, it was the 40.00 sensor. I ended up paying about $270.00 for the sensor, fluid, and labor from my mechanic. All the codes are gone and the Over drive light is working normally now. I have driven over 1000 miles since the sensor replacement and it is running just fine.

I just hope that some one else who is less fortunate then me, who has this issue does not end up forking out 1800.00 to a Ford dealer that says they need a new transmission and actually only needs the sensor replaced. Fortunately I had the resources to research the issue on-line and saved myself over 1800.00 since you know they (the Ford dealer) would have charged me to put the Transmission back together after they realized that there was nothing wrong with the transmission.

Hope this information is helpful one day for someone…

 

Just an FYI for future reference, when the tranny is cold shift points are higher to aid in quicker warm-ups. So with the Transmission Fluid Temperature Sensor on the fritz, the control module thought the tranny was cold and raised the shift points and kept them raised even after the tranny was warm. This will of course reduce your MPG and make the shifts a bit harder.