2001 dodge ram 1500, 5.2L V8. I have just changed the plenum gasket and completed a general tune up. When i got everything hooked up again and started the truck the CEL was illuminated and the temperature gauge rose up consistently until it was in the red. The code that is showing is p-0118, coolant temp circuit high input. I have checked and there is nothing plugging the lines, removed the air from the system, and have replaced the coolant temp sensor as it was broken. Any ideas on where to look next?

 

I had a bad connector on mine. Might check that.

 

Thanks for the feedback! I will have to check the sensor and connection tomorrow morning after I remove the alternator. Thinking it may be plugged in to loose, or not at all. When i wrote this post I had my temp sensors confused after a long day lol. Thinking I may have forgotten to plug the coolant temp sensor back in when I re-installed the intake manifold.

 

Check and see what the pcm has as a temp with a scanner. See if they match up with what your gauge is saying. Could be a bad sensor. Happened to me when I installed my air gap.

 

It was the connector. When i tried to take it off of the sensor, it broke apart into about 4 pieces. Just went to the local wreckers, grabbed a couple new connecters, wired it in and problem solved. No more CEL and high coolant temp warnings. Thanks for all of the input.

 

Glad to hear it. I dont know whats up with these connectors.

 

Yeah I don't know. The connector was really seized onto the sensor itself. I had to take a pair of needle nose and work the connection loose. Might have damaged the sensor a slight bit, but it is working for now so I might have to replace it later on down the road when I have some more money to put into the truck.

 

Might be that the stuff is pushing 15 years+ old? hahahahhah

Good job resolving it for the time being. Nice to actually get to junkyard to pull such things, right?!?!?

 

My coolant gauge was not working after a tune up and it was indeed the connector as well. Got the coolant temp high voltage code