coolant sensor problem

[tackman331]

i am working out the gremlins I inherited in a 2000 f350 7.3. 110,000 miles automatic tranny.


With the genisys scan tool the coolant temp is reading -40 degrees although the gauge on the dash shows the sensor working properly. I also shot the engine with a temp gun at operating temp. and it was in the 180 range.

So I think the sensor on the front of the engine tells the gauge on the dash whats going on, Does anyone know what tells the computer what is going on? I think if I find that info I will find out why I get the false reading from the scan tool.

I just did a quick search and found that the pcm doesn't mointor the engine coolant temp on the automatic transmission. Is the good info?

[NoRalPh]

We've known for sometime that the coolant temp reported to scanners is not accurate. Here's what the AE forums say about it.

"They confirmed that the pinout is there and AE sees it but the 7.3 application does not use this pinout so it floats - the result is that we see bogus information. Just ignore it, it's a result of Ford using the same hardware for multiple applications."

[tackman331]

Thats good to know, as this is my first diesel, I'm learning a whole lot of info real fast! lol