what sensor is these please

i thought it was a coolent temp sensor but its a two wire there is only one its a single yellow wire with red stripe that comes out of the hard black plastic wire houseing and clips to a sensor on the back of motor next to a little hose, here is a link to a pic of the sensor thanks for any help casue i cant find it in the book http://i76.photobucket.com/albums/j22/nayber_photos/sensor.jpg

 

ya here is another but you cant see it from this angle if you look at the left side (red arrow) if you where to follow that harness behind the motor where it turns goes into the hard plastic cover is where it is when i took the old sensor out there was coolant in the hole but i droped old senor and cant find it now go figure
http://i76.photobucket.com/albums/j22/nayber_photos/sensor2.jpg
here is the wire which of course is broke
http://i76.photobucket.com/albums/j22/nayber_photos/wire.jpg
the sensor is right next to where this hose connects on motor
http://i76.photobucket.com/albums/j22/nayber_photos/sensor3.jpg

 

does it mount to the block. and if its got coolant in it. then im thinking the temp sensor for the coolant.

 

yes look at new pics the book shows the temp sensor having two wires there is only one coming out of that loom so either i have a wire missing then or its some thing else damn truck thanks

 

after lookin at that diagram looks like it could be the EGR Gas Temp. Sensor but i dont even know what that is so

 

the truck is a work in progress it was not runing when i got it turned out the timming was 180 off i re did timeing and the check engine light when off however it ran for a few mins then died i think the fuel pump was shorting out. but i think that is the sensor i need (erg) what would happen if it was not hooked up ? thanks

 

well i looked up the sensor and its got two wires on it two what the hell well at least the pic i looked at im lost, on that dighram you posted is there a differeance between 2x4 and 4x4 mine is a 4x4

 

On a 5VZ V6 - if it's got one wire only, and that wire is yellow with a red stripe, it's your water temperature sensor / sender.

 

see thats what i thought to but this one is in the rear and lookin at the sensor diagrams it looks like it could be the erg temp sensor but i dont know for sure as i dont have one there to compare to new ones