The front AC works fine but the rear quit working a couple of weeks ago. I started working again a few days ago but now its dead again. I found instructions for the EATC self test and i get code 1251. What do I need to do now ?

 

Here's what I came up with, B1251 A/C in-car temperature sensor open circuit.

 

I guess the first place to check is at the sensor itself, if its got a break in it you'll get that code. I suppose a bad sensor would keep the A/C from running since the EATC wouldn't know what the air temperature is.

 

Where can I find the sensor ?

 

What year vehicle do you have?

 

2007 Expedition

 

It's just to the right of the steering column. It has a 2-wire plug with a Green/Blue and a Gray/Blue wire going to it.