'03 Accord A/C Problem Codes?

We have a 2003 Accord V-6 w/Nav and auto heat and A/C. Lately, there
has been a problem with the A/C suddenly coming on and blowing very
cold air when it doesn't need to. My experience with auto systems has
always been that the A/C runs most of the time, and the heater is
modulated to maintain the set temperature. I have never seen one that
blasts out cold air at seemingly random times when the car has been
running for a while. I know it will do that when a car is hot, and
you first start it up. It never did this until a couple of months
ago.

I took it to the dealer, and they said the tech tried it out and it
seemed normal to him. They also said there is no computer test for
the A/C per se, and they would have to take the underdash unit out to
check it. I think that is complete hogwash. I can't imagine a 2003
vehicle that can't be diagnosed for system problems without taking
everything apart. Even our 1993 Jeep has pages of diagnostic codes
related to the automatic HVAC system. I don't have the shop manuals
for the Accord. Can someone tell me if the dealer is full of prunes
or not?

Dick

 

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Your suspicions sound right. Why not just get a manual off eBay? Are you
keeping your rad and reservoir above the MIN mark? Your computer can
start doing all kinds of unusual things if the coolant level in the rad
gets low. Just a thought.
'Curly'

 

Thanks Curly. I'll check it this morning. Although just having come
back from the dealer for routine service, they should have topped off
all fluids.

Dick

 

Your interior temp control is probably ultimately effected through the
use of motor-activated blend doors. I don't have a service manual for
the Accord, but the RSX has a heater control valve, which is also
operated by a motor.

The problems you describe sound like blend doors not opening and closing
properly. This may be electrical or mechanical.

The Service Manual will have a large troubleshooting section on the A/C,
as well as copious, well-executed diagrams showing how the system works.
Of course, none of that means anything if the mechanic is too lazy to
open the book...

The dealership should also check for TSBs, in case this is a known
issue.

You are correct. There IS a "chicken dance" that must be performed in
order to extract trouble codes from the A/C control unit. This "dance"
is detailed in the service manual, which your dealership surely has a
copy of.

He not full of prunes, he's full of what you eventually get when you eat
lots of prunes.

By the way, your warranty MAY still be in effect. Check your purchase
agreement. This is something that should be covered, even if you're just
out of warranty.

 

A questionoes this only happen when you have the system turned to
"Defrost"?

And what's "a while"?

 

A while is after the engine gets up to temperature. But I have also
seen it start throwing out cold air shortly after leaving home. It
could be 45 degrees outside and the A/C comes on. Before all this
started, the system would not put out anything at that temp until the
engine was warm, then it would begin heating gently.

The system is set to full automatic for normal heating and air
conditioning. My side is usually set a couple of degrees warmer than
my wife's side, but that shouldn't make any difference.

 

So before that the system acts normally? This is important. ALL details
are important in these cases.

Oh, okay...

If set to full-auto, the A/C will operate while attempting to
defrost/defog the windows. This is done in order to dehumidify the air
so as to facilitate speedier defogging. If the blend doors fail to
function correctly, you will feel the cold air coming out of the vents.

You need to find a more diligent dealer. Honda provides dealers with
piles of information on A/C troubleshooting over and above that
available in the shop manual.

 

Yes, I knew the A/C worked for defogging, but it shouldn't be ice-cold
air. It should be heated. I agree, the blend doors are probably not
working right. Problem with changing dealers is that the next one is
100 miles away. Maybe I can go to a good A/C shop. I know of one.