My A/C problems solved
 

Took my 8 in for its first checkup. The a/c was on the to-do list. I had already insulated the frosty pipe.

Initial test was 49 deg. C. coming out. They evacuated 1.8 ltrs of freon and did a nitrogen pressure test. No leaks. They recharged the system and it took 2.4 ltrs.

So bottom line, it came from Mazda with not enough freon. It now blows 41 deg. C. and does not cycle on and off.

i'm sure you mean degs F not C cause otherwise thats one warm A/C unit :)

thanks for the tip though, i think i might need to do the same thing to my car next time i take it in.

You're correct. Thanks.

After reading the frosty pipe thread, I think we *make the assumtion* that the system on a new car is going to be fully charged. In my case it wasn't.

Mine wasn't either. I was getting 55 deg F. Dealer did the AC Amp TSB and found the system to be low on freon. They flushed and recharged the system. Now I get 52 deg F.

I don't know if its worth complaining again. What else could they do to get my temp down?

I brought the AMP TSB to their attention. He told me all they can do is plug my VIN # in and that will determine automatically what I qualify for (or not).

the short answer is, cars built after 9/2003 don't qualify for the AC Amp TSB (i think).

if your car was built after 9/03 or your have had the TSB performed, you can reprogram the A/C. I never had a problem with my A/C, but decided to try reprograming it anyways, and now it is even colder than it was before.

these instructions have been posted before, but to save people from searching...

1. Make sure the car is off AND the HVAC fan is off AND the A/C on/off button is off.
2. Press and hold the front defroster (on the left) AND air source (recirc/fresh air) buttons
3. Continue pressing the buttons in step 2 and turn the key to ACC for 3 seconds
4. Continue pressing the buttons in step 2 and further turn the key to ON (NOT START) for 3 more seconds.
5. Verify the programming update by observing the REAR defroster LED blink 3 times.
6. Release the two buttons from step 2 and start the car.

>...... you can reprogram the A/C.

What do you mean by reprogram the A/C? What will that do??

I just have the A/C regulator being replaced under TSB last week, but it doesn't really feel much difference at all! Maybe I should have ask the dealer to check and see if I've enough freon to begin with.

When you turn on the A/C with the MODE button set to FACE and turn the thermostat to full COLD (max counter-clockwise setting) the RECIRC should automatically engage. In addition, the amplifier should put out colder air (~ 5-10 degrees F colder and not just from the RECIRC setting) and the compressor will not cycle nearly as often (which some of us found annoying).

Note: This programming change is not persistent. If the battery is fully discharged or disconnected the procedure needs to be repeated to re-enable the settings.

>If the battery is fully discharged or disconnected the procedure needs to be repeated to re-enable the settings.

In other words if my battery is never being recharged or disconnected before, there is no need for the above procedure (ie reprogram) done to the A/C

no, you still need to do it, because it is not the factory default programming. why, i have no idea.

In other words the reprogramming is to change the default setting coming from Mazda, am I correct? Then what's the factory default setting??

I tried your reset procedure at lunch, and it prompted the flashing light you described, and ... I think maybe the A/C was more powerful. Not sure, though. It did seem icy cold for the first time in a while.

>if your car was built after 9/03 or your have had the TSB performed, you can reprogram the A/C.

Mine is built before 9/03. Is that mean I cannot re-program it?

Correct - probably not. You will need to get the A/C amplifier replaced. There is a TSB about this problem with earlier cars.

I think they've replaced my A/C regulator. Is the regulator the same thing as amplifier??

According to the bulletin it simply makes recirculate the default setting when the other parameters are met (face, ambient temp...)

BUT, I found it to noticeably improve the AC performance. And, since I was already using recirculate regularly it is NOT simply because it's now the default -- unless somehow the manual recirc selection wasn't really working before. I don't really understand what else the reset did but the performance improvement is unmistakeable. Much more than could be ascribed to a placebo effect. It seems some other folks are starting to get similar results.

My car has a Jan 2004 build date. So, supposedly the "new" amp, but it never had been "programmed" until recently when I found the instructions posted in the tech garage section.

My A/C seemed OK, not super cold, but good enough for our hot Hawaiian sun. So I never paid that much attention to these A/C threads and had no idea you could reprogram it yourself. Thanks Glyphon!

My car is a Mar. '04 build, but with the default setting. I just set the program to this one and it seems a tad colder. Really hard to say though for sure, as my A/C seemed fine to me before. I like fresh air, so the default of recircle is a pro and con. The pro is the when the car is hot, the a/c doesn't initially blow all that hot air at me at start up anymore. The con is I now need to always set it to fresh air again.

I just bought my Shinka (2005) so is there any reason why I shouldn't try this? (Before I F up my car?) heh.

I've tried to reprogram my A/C per suggestion above but that doesn't seems to work for me at all (the light didn't even flash after I've tried the steps). The built date on my car is 8/'03 and I've the A/C regulator replaced already.

i thought it was supposed to work with the updated a/c amp for the early production cars, but i guess it doesn't. sorry :(

RotaryZZ, are you saying regulator and amplifier being one in the same. I have an 07/03 build that had the amplifier replaced (little black box beside the gas pedal) a couple months ago and it does exactly what the programming instructions says it will do once programmed. If I try to do the steps to program it, the light will not flash since it is already programmed.

Do the 2005 model year cars cycle their A/C constantly every 10 seconds or so like my early 2004 build does? I took it in for service only to have them tell me it was fully charged and operating normally. When inside the car you can feel the temperature of the air coming out of the vents change each time you hear the audible click of the A/C cycle. Is this really normal?

Yes they do. I was a little annoyed by this at first, but now I just open my windows or turn up the radio. :rolleyes:

Does anyone know what the spec temperature that's supposed to come out of the system? The techs should have some idea of the temp vs ambient. I keep reading people with temps like 45~49 deg F. I had the TSB done and it lowered my average temp from 55 to 52 F.

I want to complain to the dealer but need to know if I'm out of spec.

i never felt my a/c cycle (nor heard it) on my 2004 rx-8, even before i reprogrammed it. now, its just colder.

Most of the Automotive AC thermometers I have seen show an "acceptable" area down in the low to mid 40's.

>...... RotaryZZ, are you saying regulator and amplifier being one in the same. ........

Well, I thought they're the same thing, aren't they?

I'm not 100% sure if the performance of the A/C has improved after the new regulator/amplifier. Regardless, the A/C can't quite handle once the heat outside has gone up to 95F+ or so. Maybe I should have asked the dealer to check on the freon level next time.

certainly couldn't hurt to have them check it, since that seems to have been the cause of a few members a/c woes.

I am so glad I reprogammed mine the other day! Yesterday it was 99 outside and I had my fan on 2, a/c on max, and I was literally cold inside my car. So nice.

Glad to hear one RX-8 is actually cooling frosty. I have been to the dealer and 52 degrees is the coldest they colud get it.
If there is the #1 dis-satisfation on my RX-8 is the AC...at times at the stop light it will cycle and blow a spurt of hot air, the dealership still cant figure that one out.

try reprogramming your a/c. also, have them check to see that it has the specified amount of freon in it. seems a some people have found that their systems were a little low.

I just tried this on my 6 week old Shinka (05) and unless I'm hallucinating, the air is significantly colder now... weird!

What does that re-program DO exactly, just curious - because if it was "supposed" to be that way, wouldn't the car come that way stock?

Yeah; and isn't it weird that you can toggle between two sets of firmware like that? Why would Mazda have a second set of settings hidden away in the car? But if you go back through this thread, you'll see a description of how it changes. IIRC, it now goes into recirc mode and stops cycling as much.

The programming can be lost when the battery, A/C power or ECU is disconnected (car servicing, etc.).

yup, that was noted in the post following the instructions on the first page of the thread, but since its very easy, and takes a total of about 10 seconds to perform, its not that big of a deal...one just has to remember to do it after the battery has been disconnected :)

Not sure if Mazda has a temp spec, but, when you take the reading, where you take the reading, the fan speed are all going to affect the reading.

ie, if you take a 5 minute ride with the fan on 3 and recirc vs a 15 minute ride with the same settings. Theoretically, the longer you run the system, the colder the parts get so less heat to deal with, lower readings. Most of the a/c enhancing products tell you to run for 15-20 minutes for final stabilized readings.

Bumping an old thread instead of creating a new one.

My car was built 9/22/03 but it wont take these steps (no defrost blinking light after steps complete). Is there something I'm missing or are cars built in 9/03 considered "before" and not capable of this updated programming.

I don't recall seeing this.
When I get a chance, I'll try it on my '04.

I'm guessing the last 6 of your VIN is between 000001-118171? If so and the programming doesn't work as described, your car still has the original A/C amplifier. I just replaced mine (about an hour ago!) with a later-04 unit I picked up for $50. The programming works now.

111*** So yea that must be it! Thanks for the clarification. Was it worth swapping the A/C amplifier? Noticeable difference?

I think it made a difference in the overall temperature. It seems to blow colder, but the compressor still cycles on and off every 10-20 seconds. So the warm-cold-warm issue was improved, but not solved, since the "warm" is when the compressor cycles off for a couple seconds. Next step I'm going to take it in and have the whole system flushed.

It was acceptable driving today in ~95° heat, but we'll see what happens when it hits 120° this weekend (no, I'm not making that up, weather.com says it will hit 120 on Sunday and Monday!)