[JS1581]

I bought the car last Thursday. It's a 2011 CTS premium coupe AWD 3.6. When I test drove it, everything seemed to work fine. Now, the control panel is going nuts. The temperature up button changes the stereo from am, fm, and xm. When you do turn the heat up to 80 or so where I like it, It goes all the way back down to 60 by itself. Everything else works for the most part except for the temperature control and the stereo which I guess both work off of the same panel I think? It won't read CDs either. The pop-up screen works the backup camera works all of that but the temperature control in the stereo or duking it out with each other so to speak. Could this be a temperature control module and panel, or should I just replace the computer and have it flashed to my VIN? Some feedback would be appreciated ASAP because I take the car back to the dealer to have them look at it Friday. Also I hooked my scanner up, and it's not throwing any codes either.

 

[NorthernSRX]

Does the car have a sunroof?

A lot of weird electronic issues in these cars can be traced to water infiltration from clogged drain tubes: Stop the (soaking carpet) Insanity Forever! - Ultraview...

Congrats on the car. Once you get past this, they're truly great cars.

 

[JS1581]

I know, my 2011 sedan got totaled two weeks ago because someone just decided to turn left out in front of me in a 45 mph intersection. Lucky for me I didn't feel a thing honestly. I knocked his front wheel about fifty yards down the road though lol. Anyway, the car does have a sunroof It doesn't open all the way so I'm not going to test that with the snow and everything at the moment. My buddy actually said to check and see if it was a flood car that came from a flooded region or something 🤔. My mechanic that I go to with stuff that I don't want to tackle told me that from 2008 to 2012 CTS were bad with computer issues as well.

 

[Long]

Sounds like water infiltration although coupe models seem to be immune to the typical sunroof drain plagued issues.

 

[JS1581]

It just seems to be an electrical nightmare so far. But the outside and interior look like they're brand new. It has 50,133 miles. That's what's kind of throwing me off about the issues 🤔.

 

[JS1581]

Sounds like water infiltration although coupe models seem to be immune to the typical sunroof drain plagued issues.

I fixed those issues with my sedan right away. I figured that out when I seen stains on the headliner (which I had to steam out). I'm pretty particular about my vehicles. Cadillacs are what I drive, and my Cadillac is my baby. I try to fine tooth comb everything. I don't even know if the coupes have the panoramic sunroof like my sedan did 🤔? It's a premium, so I would imagine it would have a panoramic if it came with one but not sure. I've just never had a car that if you hit the temperature up button that it'll change the radio station. I think I'll just have to go with a new computer and have it flashed to my VIN. I wouldn't think it would just be the temperature control panel. Could be a temperature control module maybe?

 

[JS1581]

I looked at every fuse and relay in the car as soon as I got it home and got it in the garage. Drilled out the PCV valve right away, so it doesn't consume oil and gets rid of the positive crankcase pressure. I know the CTS pretty well.

 

[Long]

I fixed those issues with my sedan right away. I figured that out when I seen stains on the headliner (which I had to steam out). I'm pretty particular about my vehicles. Cadillacs are what I drive, and my Cadillac is my baby. I try to fine tooth comb everything. I don't even know if the coupes have the panoramic sunroof like my sedan did 🤔? It's a premium, so I would imagine it would have a panoramic if it came with one but not sure. I've just never had a car that if you hit the temperature up button that it'll change the radio station. I think I'll just have to go with a new computer and have it flashed to my VIN. I wouldn't think it would just be the temperature control panel. Could be a temperature control module maybe?

The coupe does not have a panoramic sunroof, it only vents upward slightly.

I looked at every fuse and relay in the car as soon as I got it home and got it in the garage. Drilled out the PCV valve right away, so it doesn't consume oil and gets rid of the positive crankcase pressure. I know the CTS pretty well.

There are mixed opinions on enlargement of the PCV orifice.
I personally have not done this modification.

 

[JS1581]

I was told by a veteran Cadillac mechanic that I should do it. After I did it, it didn't use anywhere near as much oil as it did before. Might use a quart in between just topping it off. Used to use a quart a month topping it off. Added a little pep as well. Releasing that positive crankcase pressure will free up more power as well. My buddy builds drag cars, he told me that was the best thing I could have done for that car If it was using oil like that. Drill the single hole side to 7/64, and the two hole side to 5/64. Spray it out with brake cleaner and compressed air afterwards to make sure there's no gunk and metal shavings left in the valve. Multiple times preferably just to make sure. Less oil consumption, and a little more pep. It's noticable after everything acclimates.