So i have a 2008 uplander 3.9L and got message "A/C off to protect engine." The fan seemed to be running continually and the temp gauge was not moving. Anyone else had this issue? I read it could be thermostat or engine temp sensor. I went ahead and ordered both parts.

 

You should have someone run your OBD II codes. I do that for people near me for free who post such things on my local area facebook page. Any kind of code you can post here. would help us Dx your issue.

You can even buy a simple one for less then 40 bucks. The unit I use is very close to professional grade, but thats a $300 unit and I doubt you need that much power to Dx your issue.

Some auto parts stores will do it for free too, but some states don't allow. it.. Are your coolant hoses in good shape?, By that I mean they are not too softt or hard.?

 

I have a scanner, but haven't had a chance to pull the code. I will post with code when I get them.

 

Alright, so I pulled the codes. U got a p1174 for the fuel trim cylinder and a p0128 for the coolant temp.

 

"The fan seemed to be running continually and the temp gauge was not moving."

Try the temp sensor first.

 

P1174 usually caused by a faulty heated oxygen sensor located on the exhaust, or a simple vacuum leak.

 

What fixed the problem?? I have the same vehicle and the same problem with one of the same codes. I have 3 codes that popped up P0128 coolant temp below thermostat
P0127 system too rich
and P2070 intake manifold tuning valve stuck open

 

Mister Hartman hasn't been to the forum in over 5 years and probably won't answer you.
That's why it's always better make your own thread, and include ALL your relevant information (vehicle details, troubleshooting you tried, etc.)