I've come to learn the hard way the difference between a manufacture defect
(usually covered under warranty) and a design defect (NOT covered under
warranty and usually ignored unless it is safety related and lawsuits are pending).

Back in March 2002, I bought a Protege5 and soon noticed an odd behavior in the ventilation system. When I switch the vent control to"feet" or "feet/windshield" or "windshield" the AC comes on and blows cold air. To make matters even worse, the AC light does NOT light up and unless you listen closely you will not hear the compressor engage either. Well, excuse me folks, if I want the AC to come ON then I will press the AC button, otherwise where I direct the ventilation should have no relation to the AC. When it's cold and DRY outside, I prefer to have a warm flow of outside air going through and don't want the air pre-cooled (dehumidified) and then re-heated. I thought the behavior was a departure from the standard layout of most cars so I brought it to the attention of my local dealers. All but one brushed off my complaint with the answer that such behavior was "normal" and that there was nothing
to be fixed. They did, however, acknowledge that the AC light not coming ON was undesirable and the "defrost-feet" setting couldn't be explained. One service writer did not think this was "normal" and proceeded to track down the source--the onboard computer (ECU) that controls most of the car's functions. He then went outside onto the lot and randomly sampled other 02 Proteges and found that ALL of them did this ! ! The service manager put in several calls to the technical department at Mazda (Irvine) where he was finally told that "some programmer in I.T. made a mistake" and that they "were working on it and would have a software patch available by September 2002". Well it's May 2003 and nobody seems to know when (or even if) the patch will be released since they're now focusing on moving forward with the the 03's, etc., etc.

This episode has me wondering what other mistakes are under the hood waiting to reveal themselves. Since Mazda relies so heavily on its Protege line, why would they assign such a low priority to such an easy and inexpensive correction ?
Answer---hardly anybody has openly acknowledged the defect, even fewer have complained, and the Ford corporate culture dominates in Irvine.

 

umm this has been discussed many times. And it's not actually a bug, it's designed to be helpful by automatically turning on the A/C, even though it's not the full defrost setting. Of course not many people really like that idea!!!

 

seeing as the work around to this means getting into the controls and de-soldering a microswitch (do a search) I am not sure that the "software" answer you were given is a good one. Looks like the controls are more hardware than software.

 

JJB is right. THe ECU has (read carefully) NOTHING to do with the A/C coming on. It's triggered by microswitches in the HVAC controls. To eliminate the A/C "bug" you have to de-solder them. The car was designed this way, and it's not a bug.

 

I got to thinking that I recalled that there was mention that the A/C compressor was disabled when the car was at WOT and this lead me to think that somehow the car must be able to turn off the A/C when it wants to.

I started poking through the workshop manual and sure enough the A/C control signals are routed through the PCM. It looks like it is the PCM that engages the A/C compressor clutch and also monitors things to turn on the condendor fan when needed.

But, the HVAC system's other components and signals do not appear to be routed through the PCM. This would imply that they are connected directly to their own devices. So, that would mean that the HVAC control is the one that tells the car to have the A/C on (and the PCM just turns it on). This would then confirm that there will be no "software fix" for this issue. You would need to get into the HVAC controls to get around it.

Just a little more information.

 

The current generation Protege is nearing the end of its production run in favor of the new Focus based Mazda3 (or whatever they're going to call it). Partly because of this, Mazda will never, NEVER release any kind of design flaw fix for any reason whatsoever-- Short of a massive lawsuit, which also will never happen.

I'd suggest things like this 'foot setting' defrost crap is ghetto butt-*** irritating and an offensive waste of fuel and resources, but aside from that there are no safety issues associated with it, so Mazda couldn't care less whether we're annoyed by it or not.

Now, if we stacked up the collective thousands of extra pounds of exhaust that are produced by the Protege because of this dumbass foot setting on top of Mazda executives, or perhaps sent them a bill for the millions of extra dollars we collectively have to pay in wasted fuel, maybe then they'd do something about it, but people don't think about pollution in tangible terms, sad to say, nor do they often consider how much fuel really costs people.

********.

 

The 2002 Proteges don't do it.

Who cares anyway?

Waste of resources? Ghetoo-annoying? WTF are you talking about?


The AC lowers my fuel economy by 1-2 mpg at most.

Boo-*******-hoo.


Put down the crackpipe.

 

Yes and no...
My perception of A/C is that it makes the air DRIER (not compressed, at least upon entry into cabin).
It makes the air drier by cooling it, which lowers the dew point causing condensation.
This "dry" air, then is introduced into the cabin (or on the window) and readily absorbs the moisture into this formally "dry" air, which is recirculated, cooled (and dried) and the process repeats...

 

fossil boy- your perception is correct. it lowers the dewpoint of the air which seperates the water out of it, then it blows the dry air up onto the windsheild and strangely onto your feet.
it doesn't compress the air in any way.

 

Wow on all the things people whine and bitch about on their cars.. paint, cold engine noises, etc.. someone whines about something that ACTUALLY has impact on how the car runs (fuel economy) and the best reply you have is boo-*******-hoo?

Rick Hart has the same right we all do to complain about the small annoyances Mazda will get away with... atleast he's putting his energy into something remotely useful and environmentally impactful, where as the rest of us (me included) are upset the cars paint or windshield doesn't look as pretty as we think they should..

The "too bad, so sad" replies on this thread are rediculous..

 

Wow, this has been covered to death even in the short time I've been here...

It can be changed with a soldering iron (so I've read). I agree that you should have full control, but I've learned to live with it, like I learned to live with the power seatbelts in my Fords (and I REALLY HATED those things).

And BTW, since I learned about this, and started exercising more control over the HVAC system, my gas mileage has gone up at least 3mpg.

 

I love that we only have to complain about little stuff like bad paint or whether the AC is on or not. Just think, you could be driving a Rio! Or a Dodge; since the day my parents bought their Caravan they've had paint falling off in chunks, three transmissions, electrical problems forever, and broken engine mounts. They constantly worry about being stuck somewhere when it dies.

 

My point exactly.

My friend worries if his pizza-cutter tires are gonna explode if he goes over 80 mph sending the car into oblivion, and you bitch about the a/c turning on so that defrosting works better.

 

Are you sure it comes on in the "feet" position. I never noticed that but I notice it when feet/defrost and straight defrost are selected. My Ranger was the same way.

The system does slightly compress the air entering the vehicle (similar to the effect of a CAI, the colder air is denser). It also removes a lot of moisture from it. This is because as the air passes the evaporator it is cooled rapidly and the water condenses onto the evap fins (this also serves to trap a lot of the crap attempting to enter the vehicle, gets stuck in the condensation). Having the dry air is very helpful in defrost situations where liquid is condensing inside the windshield, otherwise it has no effect. In those situations where the dry air has no effect you heat the windshield (and the air near it) and help it absorb the outside liquid (very slowly). I honestly feel it is something very stupid to be complaining about, unless it actually is on in the feet only position (then you should feel free to bitch, that is just plain dumb). It keeps a lot of morons out of trouble.

 

The A/C DOES come on in the feet only position.

Sir, bitch away.