How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Ted G. Your Own Question
Ted G.
Ted G., ASE Certified Technician
Category: Car
Satisfied Customers: 6155
Experience:  20 years auto repair experience, ASE Master Tech, Mechanical Failure consultant, Expert Witness
Type Your Car Question Here...
Ted G. is online now
A new question is answered every 9 seconds

GMC Terrain: I own a 2011 GMC Terrain with 16, 045 miles on

This answer was rated:

I own a 2011 GMC Terrain with 16, 045 miles on it.
My A/C unit per the dealer "is functioning perfectly". The problem I've noticed is that the unit is really weak. During warmer days, 95-100 degrees, the unit blows cool air not cold and it takes at least 40 minutes to cool down the entire cabin.

I've also noticed that the unit will sometimes blow really cold air during select moments then revert back to the cool air.
I read some posts that indicated that it may be attributed to the temp sensor at the condenser, can someone give me some insight on this?

Thank you,
Can you give me your VIN please?
Customer: replied 4 years ago.

My VIN # XXXXX: 2CTFLUE58B6397520

Sorry, this question kind of got lost in the system. I had thought there was a bulletin on your vehicle for AC issues but it deals with smell and not performance. The newer AC systems do not cool as well and usually have to be on recirc to really cool, but there are no noted issues with that vehicle related to poor cooling.
Customer: replied 4 years ago.

Hello Ted, just so I'm clear.


Reading your response are you indicating that you've never experienced a GMC customer complaining about the efficiency of their A/C?


Also, when you say my question was lost in the system, what exactly does that mean as I've been waiting for an answer since Tuesday of last week?

Not on that particular vehicle, no. Our system is suppsed to prioritize questions that we still need to work on. And highlight questions that have responses from our customers but for some reason yours dropped off my priority screen, probably just a glitch, and it seems to be fixed now. Sorry for the delay.
Customer: replied 4 years ago.

Ted, I did my own research and discovered TSB # XXXXX "Unwanted and erratic temperature changes in HVAC operation in air distribution. "

How did I find this and you were unable to?

Because I looked at bulletins and forgot to look at the PI's (preliminary information). That was my fault. There are actually 2 PI's that relate to your vehicle, that one which has to do with repairing a possible chafed wire, and PI 0611A Poor A/C Performance, A/C Intermittently Blows Warm Air, Lack of or Reduced Air Flow . I suspect that the second one is related to what you're experiencing because it involves reprogramming the computer. I thought that there was a reprogram for that which is why I asked for your VIN in the first place (then I forgot to check the PI's-old guy, too many brain cells gone). Since you said it works well sometimes that would indicate the mechanical section is working well, but the module is not performing properly.
Customer: replied 4 years ago.

Ok, so how do I approach the dealer with this or should I go to a certified shop?

Well, you should be under 3/36 warranty so I would ask the dealer to research the 2 PI's and at least perform the programming update. Some shops can also due that update but many,many have not learned how yet, and they would have to charge you anyway. The one you referenced is also fairly easy to do and will be visually failed if they go in there, since they missed the PI's (like I did) they should really do both for you without complaining too much.
Ted G. and 11 other Car Specialists are ready to help you