A/C blowing hot air

[Terrance05]

Hey I'm new to the forum. I found a lot of helpful information, which helped me find out that my LS needed a new PCV valve from the codes I was receiving. I recently had the PCV valve elbow switched out by a mechanic today. Now that I received the car back, my A/C is blowing hot air even on the low temperature. What could have caused this error? I have not consulted the mechanic about it as of yet due to he was closed when I found out. Just curious if it was something he could have done.

[shorod]

Welcome to the forum!

Thinking through what I remember of the process, about the only logical way he would have been working in the area of the cooling system would be from removing a couple of coolant lines for the throttle body/upper intake, but that really shouldn't explain getting heat only. If he drained the cooling system rather than just clamping off those lines, he might have disturbed some settlement in the system which now has caused the Dual Coolant Control Valve (DCCV) to stick in the open position. Stuck DCCV's are pretty common, and if that's what happened, it's not the fault of the mechanic.

You can search this forum for the instructions on resetting the Dual Automatic Temperature Control (DATC) as well as pulling diagnostic codes from it. That's where I would start, then either you or him carefully inspect under the hood to make sure everything is correctly connected, specifically the wiring to the DCCV which has a connector near the passenger side top of the radiator and another connector on the DCCV itself.

-Rod

[Terrance05]

Just to make sure, is that where you are pressing buttons simultaneously to get codes? I was randomly looking through here about the DCCV and the code P1409 b/c I have that right now as the result of this work as well.

[shorod]

Once you've read the codes, you can press another button to reset everything.

-Rod

[joegr]

What year is this mystery LS? There are some distinct differences between some years, including how to start the diagnostic from the climate control.

[Terrance05]

Re: A/C blowing hot air
What year is this mystery LS? There are some distinct differences between some years, including how to start the diagnostic from the climate control.

It is a 2001. I actually did the self test and now it is working, so it must have just needed to be reset as Rod stated. I will keep an eye on it and see. Now I just need to tackle the P1409 code and I should be all good. Thanks Rod.