spleify

We were out wheelin over the weekend and went up to 12,800 ft and it was in the 30's up there yet my temp gauge held steady at 68 degrees for almost the entire trail. we were on it for about 5 hours.

Someone mentioned that if you drive under X MPH for X distance it stops reading. Whats up with that? That is the most ridiculous thing I've ever heard.

Alec

I believe that the sensor is in front of the radiator and condenser. It's possible that while still or at very slow speeds, there's not enough airflow over the sensor to counter the ambient heat from the engine compartment. I don't think the sensor would stop reading, it just doesn't know the difference between heat from the sun and heat from the engine.

I've seen this with many vehicles; there are only so many places you could put the sensor and they all have pros and cons. On my GTI, the sensor was in the lower grille area. When you install the fog light kit, the fog light sometimes heats up the sensor.

spleify

Yes it is up front. I see what you are saying but it seems like it would have changed to something other than 68 degrees it was damn cold at the top of that mountain. Then when we cot back on the highway and started moving it started working again after while.

wytmike

This was posted a while back:

Vehicle with the key off for more than 4 hours...The CCN will update the ambient temperature reading immediately.

Vehicle with key off for more than 2 hours but less than 4 hours....The CCN will update the ambient temperature reading immediately after vehicle reaches above 20 mph (with no duration constraint) and will update every 500 ms thereafter.

Vehicle with the key off for less than 2 hours...The CCN will display the last temperature reading (which is stored in memory) just prior to the ignition being turned off. The CCN will not update the value in the display until the car has been driven at 20 MPH or above for 3 consecutive minutes.

If the vehicles speed and drive time doesn't meet the criteria the CCN will
continue to display the stored value until the criteria is met.

Once the criteria is met, then the CCN will update the display every 500 ms based off of the ambient temperature sensor output.

Looks like you didn't get going fast enough. Not the greatest system if you do a lot of stop and go driving.


Hope this helps

Mke

spleify

Yep that sounds like what it was doing.

We probably never got over maybe 8-10 MPH for 5 hours. There was definitely no 20 MPH speeds on these trails.

Thanks for the info.

It is really a stupid setup. Why the heck should the speed I'm going have anything to do with what temperature it is outside??

Ghost63

I have seen a similar effect with mine. When leaving the garage and going out into the cold, it takes a couple of minutes before the temp guage gives an accurate reading.

ronjenx

As stated above, when moving slowly, you will get an erroneous reading. So, it just displays the last good reading until you go faster again.

Alec

Because they figured it's better to give you a past reading than to give you a new reading that's way too hot (engine heat).

Below 20mph, there just isn't enough airflow over the sensor to counter the engine heat.

JeepaRoo

it seems to me to be 40 MPH that gets mine.. at least it was in my 09 and seems true in my '10.. I often go to lunch up the street a few miles from work.. the cops are bad so I go 35 and thats it... at one point its about 5 or 6 minutes of steady driving, no lights or such.. and at 35.. my thermometer will often stay frozen... seems its more coolant temp based than it is time based.. my jeep has been parked for close to 4 hours and the temp didnt change.. if it is windy outside it seems the temp will operate more normally when I first take off.. indicating it may be related to how much the jeep has cooled down since it was last driven....

I know thats how GM's outside temp gauge works.. related to engine temp as to how it acts when first driving...

if I take off in my jeep and go above 40 MPH pretty quickly.. I dont have 3 minutes in delay, the temp will begin resetting itself accurately...
-Christopher