Temperature Displays 0C

[EricCartman]

Hi All,

I'm trying to help my father figure out what is going on with his 2004 Tahoe. It seems to be displaying 0C on the temperature display.

I did some preliminary searches on google... and I found that in all likely hood the 0C = Open Circuit - meaning one of two things...

1. The temperature sensor is disconnected
2. The temperature sensor is bad.

To throw an additional wrinkle in the mix... the windshield was replaced while the vehicle was sitting.

I'm wondering if perhaps the wiring could have been disconnected in the process of replacing the window. It seems like it could be possible, but I want to make sure that it actually is before I call and ream out the windshield replacement company.

Also - I am trying to locate the senor for the temperature. I believe if I find the correct wiring harness that plugs into the mirror/sensor - if I jumper across the pins with a paperclip it will read 5C = short circuit.

If I can induce the 5C condition... at least I will know the mirror is still connected to the other end of the harness - and that the sensor is bad.

However, I do not know where to find the sensor. Some folks have said it is on the radiator support bar, other say near the tranny.

I'm a little nervious to find something that I *think* is the correct jumper and putting a short across it. Not a fan of smoke and fire in a vehicle.

I believe I found it... but I'm hoping someone could either refer me to a schematic diagram for this system - or could confirm the wire colors/location of the sensor circuit.

I know... I should buy a Hayes/Chilton or some other brand manual for this thing. But, I haven't got around to that yet. Ideally, I would like to have the FSM. Anyone know where I can find an electronic copy of that?

Anyway, any input would be greatly appreciated.

Thanks,
Cartman

 

[EricCartman]

Fixed...

I figured I would follow up with the results I had just in case any body else happens to have this problem in the future and finds this thread...

I started by locating the temperature sensor. It was in front of the radiator, towards the lower left (driver) side of the vehicle.

I had to remove the plastic housing that was on top of the radiator area. It was not too hard... just pull the plastic pins with a flat head screw driver.

Next I unplugged the harness from the sensor, and pulled the sensor from the mounting location.

I measured between the two pins on the sensor - and I got something other than an open circuit... it was changing as I was holding it (it was getting warmer), so I concluded that this part was functioning.

I then measured the impedance between the two wires on the connection... open circuit.

So, I checked the other extreme end of the wiring harness (at the mirror). For S&G's - I unplugged the harness from the back of the mirror. I re-inserted the harness to where I thought it was in all the way. Then, I gave it one more push to make sure it was seated good - then it clicked in. I checked the functionality of the temperature sensor and it was now working!

I'm guessing that the guys that replaced the windshied did not fully seat the connector when reconnecting the mirror.

It pays to check the simple stuff first.

I'll add a few key words to the post so that if someone searches from google (like I started doing), they might be able to find it...

Display 0C
Thermometer not working
Temp gauge not functioning


Cartman

 

[Old Goat]

Good thinking. Congratulations.

 

[01_Tahoe]

This helped a lot, thank you! Having the same problem on my '01.