I did some testing today and the switch off point is 5750 rpm. I am on the hunt to find this over the next few days.

 

good luck if u need any assistance let me know!

i am 88580014.

Thanks again

 

I may have found another minor issues with Evoscan and the logging of the A/C output. I have the output relay listed as MUT 49, but I believe it has been a mis-type since early versions. For my car logging MUT 49 has always come up as nothing. I changed to MUT 4A, as per the input switch, and it seems to log correctly if a little erratic at times. Has anyone else found this?

 

i can try it.

is it as simple as placing **** into my MUT 4A tables?

what do i need to add to evoscan?

Thanks

edit...

just looked in evoscan 2.5 i have it as 4A for the air conditioning switch.

 

good luck finding it guys

this would make a good "mod"

 

It is not the switch, we need to log the output to the relay which turns the A/C compressor on and off.

I did some testing today and I cannot find anything that I can reliably log as the A/C output. Has anyone ever 100% verified a MUT address to log the A/C output?

 

as per my v6testing thread.

try logging MUT9A. i am pretty sure its one of the bits in there.

and yes I am also 99% sure its the compressor on/off signal rather than switch on/off

 

Thanks mate, I will check it out tomorrow.

You know.... with 80700010 support for V6 it would make things alot easier ;-)

 

yup its on my todo

 

Woohoo, I earned my treat! :-) I just read the V6 thread from beginning to end only to see the bit about the A/C is on the last page.

FYI, I wire alot of ecu's and the A/C system will generally receive a "request" to turn on the compressor from the switch on the dash. The ECU then turns on the compressor based on conditions. So if you turn on the A/C the logged switch input should always be on, but you will see the output turn on and off to suit conditions. I think we are most interested in finding the output more than anything.

How do you setup Evoscan to log certain bits once you know from the disassembly which bit you are interested in?

 

Saw this and immediately thought of the Zeitronix Throttle Controlled Air Conditioner (TCAC)


TCAC is a great solution to keep the interior of your car cool without loosing precious power at full throttle, so your car will always feel strong, with and with out the load of Air Conditioner Compressor.

TCAC automatically turns off the AC Compressor every time the throttle is pressed over 60% and keeps it off for an additional 6 seconds after the throttle position comes back bellow 60%. Long enough to let you change gear and accelerate again, also allowing RPM to drop to the lower level before the AC clutch engages again when you begin cruising. You can also see it working when the air conditioning light indicator goes off.

TCAC is professionally designed and manufactured using the latest solid state technology, without electromechanical parts like relays, which are less reliable than semiconductors. Moreover, we use the highest quality components and very reliable soldermasked printed circuit boards in order to make a long lasting and reliable product; still at a great price. Our products are professionally assembled in the United States and rigorously tested to assure the highest quality.

A small size makes TCAC easy to mount near the ECU or the AC switch.




http://www.zeitronix.com/tcac/tcac.htm




Seems like a real easy install as well.... http://www.zeitronix.com/installatio...stallation.htm

 

matt - yeah but I think the 'input' is from the climate control rather than the A/C switch itself...

ummm bitlogging - i can't remember, you can do it - I asked Hamish to add it but I have forgotten howto do it..

 

I was a bit confused by how he labelled the bit logging as bit 4, bit 8, bit 128, etc.... I will figure it out.

Either way, the input needs to come in constantly so that the ecu can pre-empt the turning on by upping the idle control. Usually the idle mapping will be initialised a small amount of time before the a/c output is activated to prevent the motor loading up then having to react. You would generally expect to see a timer to prevent the a/c being on while cranking... something we see with around 3 seconds delay before the compressor turns on. There will be an RPM cutout to prevent damage to the compressor, and we see that at 5750rpm. Then there will be TPS and/or Load conditions to meet. Exceeding these will turn off the compressor for a certain time.

The question now will be if the climate control shares signals with the TPS, RPM, etc... and does the control, or whether the ecu does the control.

 

In the circuit diagrams there is something called the AC ECU which also has most of the inputs and some outputs into the ECU. The AC switch is an input into both the AC ECU and the ECU, from what I can tell (pin 45). Most of the other pins on the main ECU are for controlling the relays to turn on fans, compressor, etc.

I can post screenshots of the pages in the manual, if needed.

Here are my quick notes after looking at it yesterday:

pin 8 activates ac compressor relay, which powers ac compressor

pin 32/34 activate hi/low relays for condensor fan motor

pin 45 - dual pressure switch that inputs into AC ECU and ECU

pin 24 comes from AC ECU


AC ECU has inputs for outside/inside air selection damper control (pin 2/3), ac switch, defogger (pin 1), blower switch setting (off, lo, ml, mh, hi)(pin 8)

 

i still think the AC ECU basically askes the ECUECU to yes/no the A/C compressor.

the AC ECU would use various conditions to determine whether the compressor needs to be on/off then once it decides it needs to be on, it notifies/askes the ECUECU to turn it on.

ie - just because the A/C switch is on doesn't mean the A/C is actually on...