Hello folks,

I seem to be having an hvac problem.

No matter what setting I choose (floor vents, upper vents, both, defrost, etc.) I get air coming out of all the vents, however at VERY low pressure.

The control unit seems to be working properly in that it visually acts like it is changing to the modes I select. The fan also seems to be working properly. I can adjust its speed up or down, but it seems that the air coming out of the vents is very low pressure, almost so low you can't really tell its on (but the fan sounds normal)

I can get hot or cold air, so those cooling and heating systems seem to be working correctly.

I guess the root of the problem is really the air delivery system. Since all the vents are pumping out air, I guess the "air pressure" out of any given vent would be low. Can anyone confirm this?

I checked the codes and heres what I get...note, no HVAC specific codes. (These are all history codes)

SCM U1016,U1064,U1160,U1255
BCM B2723
IPC U1160

What can you guys..the corvette gurus suggest I check for this vent problem? Also, do any of the above codes seem worrysome for this problem (or any problem) I read a previous post that seemed similar and it suggested checking under the battery for a loose vacuum connection. Its dark out now, so I can't do that until tomorrow...but until then, I will take any suggestions.

Thanks

 

Your getting sporatic codes all over the place; serial data line malfunction, left door control module, passkey code, loss of comm with dcm, pcm, etc......

If you still have the stock battery, check the posts and that they are not leaking. The stock battery is notorious for this. Check your battery connections, mainly the positive one and make sure they are tight and look for acid leaking down onto your computer, which is under your battery. If this is the cause I would replace it with an Optima Redtop, unless your still under warranty. In that case, GM will replace, bad batteries have been a common problem Goodluck.

David

 

Take the passenger side front wheel well (the one behind the tire) off and look in there for a corroded tube due to battery acid leakage. If your battery has leaked (mine did and ate thru the tube) you will have to fix the tube and neutralize the acid that is most likely on your PCM and other components. The acid had corroded one of my vaccum tubes causing a leak. I noticed that my car idled a little worse, which was due to the vaccum leak I now had since the tube was open. I just spliced in some tubing from a local home repair store and that fixed mine. Make sure you check your PCM and verify that there is no acid on it or the bundles of wires that feed it.

 

I agree that leaking battery acid seems the most likely source of your problem. I had to replace my battery due to it leaking around the poitive terminal.

I've also had an a/c problem, but it was unrelated to the acid leak. HOwever, my a/c problem produced very specific HVAC module codes in the DIC. So I think that if you had a a/c component malfunction, you would be getting some sort of HVAC code(s). I'll wager a dime or two that you've got a leaking battery that has damaged a vacuum line.

 

BINGO! Man you all are good... I took the battery out and sure enough, the positive terminal was broke and was leaking acid. I'm going to have to get a new battery I guess I'll try go with the Optima, but I'll have to see if I can get it locally. Thats what everyone seems to like.

As far as the acid goes, I still need to get in that inner fenderwell today. I pulled the cover quickly last night, but it was getting dark out, so I didn't get a really good look.

At this point I would assume I have some vacuum line damage due to acid.

What do you think about all the trouble codes I was getting? Do I definintly have some computer problems, or do you think if I clean everything up in there I should be ok? (Of course I'll check for ruined wiring while I'm in there.

Anything I should watch out for while I'm in there?

Thanks