Wingshot

Hello, I'm looking for some advise on why my coolant temperature sensor keeps going out. To give you an little history. I first notice that my temperature gauge was rising to fast like my truck was overheating but it wasn't. I then replaced my first coolant temperature sensor (Off brand) and all was well for two weeks. I then noticed my temperature gauge again rising over normal levels but it wasn't overheating. This time I bought an ACDelco brand and installed it and after two days it started to fail. Before I try replacing the third one I would like some advise on why my sensors are failing? Bad wire, short? Any help would greatly appreciated.

Cavdog81

Check for any stored Dtc's. You may have a t-stat problem.

Wingshot

Thank you for replying. I tested and I'm throwing no codes at all. I tested the last sensor I took out it was still good. I'll have to do some more testing I guess. Thank you.

hicksvilleshick

Yeah I'd toss a new tstat in for good measure. Cheap and easy. Coolant flush wouldn't hurt neither.

WyrTwister

Just to be sure , check the wiring & electrical connector , going to the tstat .

Do you have or can you get a wiring diagram for this vehicle ?

I am guessing the heat sensor goes to the " computer " ? Check the connectors that attach to the computer .

Also , look for all the ground to engine / body connections . Are they good ?

God bless
Wyr

God bless
Wyr

Wingshot

Thank you all for replying.
I have changed did a coolant change and thermostat about 8 months ago. My temperature gauge was working just fine at that time.

Wyr - I do only have one temperature sensor and I believe it is also is being controlled by my ECM. I have looked at the connection and wiring going to the sensor and everything looks good as far as clean & good wire's. I did also get a lead on checking my main ground wire. I did look at it and found out where it goes. Its located on the bottom side of the motor and can't get to it real good. I'm gong to have to take off my skid plate etc. and see if I can even get to it. My first impression is, it looks like the connection is a little oxidized. I will have to take it off and clean it.

To give everyone an update. After I changed out the third temperature sensor, I check the second one I put in and it checked out good on the volt meter. This last week was very interesting because my temp gauge started to work and read correctly. It took about three days to get normalize readings on my gauge but for the last two days it looks like there was nothing wrong. I don't know what to think now.

Thanks again everyone.

starman8tdc

Update?

Wingshot

I believe the coolant temperature sensor was fine the whole time. It was the stepper motors in the back of my dash.