I've got an interesting issue with my '01 MC SS. Several weeks ago, while I was driving the car, I noticed that the temp guage went dead. I had the heater on at the time, and there was plenty of heat pouring out, so I knew that it wasn't necessarily my coolant system and/or thermostat acting up. This problem persisted for a few days, and then all of a sudden the temp guage came back to life. Not for long, however, as the guage eventually went dead again, and shortly after that, the 'check engine' light appeared. I was waiting to see if the gauage would spring back to life again, and in so doing, noticed another problem: my digital information panel (not sure what its technical name is.... it's located on the ceiling and gives readouts pertaining to temp, gas consumption, etc) would not come on after starting the car, and when it was not on, neither the heater blower nor the rear defrost worked (radio, radio lights, instrument panel lights and everything else still worked fine). After a few minutes, the digital information panel would kick in, and upon doing so, the fan blower and rear defrost functioned normally as well. This problem, however, seems to have gotten progressively worse as it sometimes takes several minutes for the digital information panel to kick in (and hence the blower) or does not come on at all. Sometimes, though, it comes on right at ignition.
It would appear that these problems happened rather close in time to one another, but I'm not 100% convinced that they are related. More than likely they are, but I can't be sure just yet. The car runs fine, and there is no dimming of the instrument panel lights as a recent poster had regarding similar probelms with his temp gauge. I was wondering if anyone had any suggestions here before as to what the possible problems may be. I haven't checked out the error codes just yet, but will probably be doing that soon.
Thanks!

 

I can help with one. I just helped 01BlkSS with his...and I just did mine. We both had the same problem as you. Seems like it's happening to everyone with a 01 MC SS too.

The problem is your temperature sensor and/or your thermostat. That's why your temp gauge went dead and you got a Check Engine light. If you go to Autozone and get a diagnostic test on the car...you'll get a code of P0128. If so, then it's the same issue as myself and 01BlkSS had.

In that case, replace the temperature coolant sensor and the Thermostat. The sensor is right below the thermostat housing.Besides...it's much easier to replace the temperature sensor when the thermostat housing is disconnected.

So, replace both. It'll cost a grand total of $25 if you replace your antifreeze too. Remember...it's Dex-cool...not the typical green stuff. If you do decide to flush your coolant...the drain plug is on the driver's side, at the bottom of the Radiator. You might want to disconnect the air dam so you have more room to work with. The air dam is 5 bolts and they're 10mm. The Drain Plug is a 3/4" socket...but be careful, it's plastic and it does not come all the way out. Just loosen it enough to drain the coolant. Don't strip the plastic plug.

After you replace both the temperature sensor and the thermostat...if the check engine light is still on...and the temp gauge still isn't working...go back to Autozone and have them clear the error code. That should fix everything.

Here's the thread on how we figured out what the issue was:
https://montecarloforum.com/m_22270/tm.htm

As for the digital info panel...I don't think it's related. I'd change the Temperature sensor and thermostat and see if that fixes the issue with the digital info panel.

 

Hmmm, sounds familiar!

I would have to agree with hckygoalie31. I'm thinking that it will probably be the coolant sensor, but I would replace both to be safe. I'm also thinking that maybe sense the computer is getting funny readings from the coolant sensor that it is screwing things up. Maybe after you replace the sensor and have the computer cleared, it will all work again. Keep us updated!

 

seems like a lot of coolant temp sensors are going lately but while your changing the sensor(if you do) change the t-stat at the same time

 

LOL...good call, Wiz. I replaced my temperature sensor without replacing the thermostat first.

What a pain. Almost no room to work with at all unless you pull the Thermostat housing off.

 

I've got this same problem to a T, so I'm going to change the guage & thermostat too. But about the panel and the heat business being related; I noticed that after the info starts reading up on top that's when the heat and defrost kick on too. Or at least the heat won't work unless the panel is reading.

If you hold down the second button from the right for a couple seconds, the panel will kick on.

 

Update: Last week I replaced the T-stat and the sensor: Temp Guage problem fixed. However, still have the same issues with regard to the information panel and heater/blower. I think, however, that the latter issue was unrelated to the former, and now believe that it may be something wrong with the ignigtion. I have found that if the information panel/heater/blower do not come on right away, and I turn the ignigtion on/off a few times, starting and killing the engine each time, eventually they will kick in. However, I have not tried holding down any buttons to see if that would change anything. Why would it? It is interesting, though, that toggling the ignition from on/off several times, without starting/killing the engine will not result in the information panel/blower turning on. Maybe it is a problem with the computer.

Another thing I've just noticed is that the first two speeds (i.e., 1 and 2) of my blower don't work! Only kicks on at 3, 4 and 5. Ever since I've had the car, I've had a problem with the 1 position, but I just thought it was blowing super low... guess maybe it just wasn't on at all. Now, though, with number 2 not working.... hmmm.....

drd

 

Same Problem, with the Temp Gauge, should be all set if I replace the thermo stat and the sensor.

thanks.

 

I replied to this on the other topic, but just to be safe I'll do it here too

Since it's pretty easy and inexpensive to replace both, I would replace both. That way you will know the problem is fixed.