When I first got Autel MS906BT in Aug 2021, the very first thing I did was killed ECO START STOP.
DONE. SUCCESS.
2nd most important priority was to DEFEAT the 30 minutes limit of HVAC Blower re-circulation function.
I really hate this 30 minutes limit as in Jakarta, smelly diesel blackie smokie bus and truck will kill you....if you have FRESH AIR selected.
DONE.SUCCESS.
But after I played around with Launch like a year ago , it seems I accidentaly disabled DEFEAT of the 30 minute limit of HVAC Blower re-circulation function.
But I managed to change other important parameters using Launch to maximize my HVAC cooling power and my HVAC blower flap stay closed when engine OFF.
Cleaner for my HVAC blower and bugs can't come in.
The best MOD is mechanical MOD, where I by-passed my heater core in the HVAC, that is God sent coldness never an M276 based W212 can ever achieved,
as we are unlucky ...... there is no electric stop-valve for coolant flow into heater core of HVAC. We loose 3-4 celsius easy at the center vent.
M272, M273 and M271.x has this coolant stop valve.
M278 and M157 older version has the coolant stop valve but you can't buy new one anymore. No valve, just plastic pipe.
Anyway, today I re-visited this 30 minutes limit of HVAC Blower re-circulation function.
I do not have my Autel with me 99% of the time. I let my cousin who has a small Indie workshop uses it and I will get him to give it back only when I need it.
This morning I looked at my old archive of Aug 2021 and found the magic setting to defeat the 30 minute limit of HVAC Blower re-circulation function.
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This setting called SPECIAL SETTINGS
The same name in Xentry. I labeled PW = Password Needed.
If you are using Xentry PassThru, you can not enter the sectionI labeled PW unless you have an active password ( subscription ).
If your are a customer of BenzNinja.com , he can do it for you.
Me, I am itchy handed, so me do it me-self.....
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If baby Launch, it fall short in this section compared to Autel MS609BT.
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The SPECIAL SETTING menu in baby LAUNCH is only above, and nothing else and also no explanation.
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AUTEL follows Xentry word for word and full menu like Xentry.
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Distorted image below is HDMI output recorder I use on the Autel, a stand alone recorder which works so well for PC.
Its like this ugly, I think Autel HDMI is not a true proper HDMI standard.
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Thus I want to know using Launch what is the information available in the question mark icon .
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Oh oh...I will die......
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What else did I do to make my aircond do maximum power ?
I killed the torque restriction on my HVAC compressor. My car is powerful enough at idling and not a pu-ssy 4 cylinder.
Look Ma...more AC power
I will update when I log the compressor power sent out to the control valve, let see what difference done by the new algo.
and if the 30 minutes re-circulated air flap is a true success like back in 2021.
I think not Pierre, because the evaporator temperature sensor is still the King Of Command, by logic of operation.
Example : Evap temp sensor is set at 2 Celsius as lowest and can't go any lower.
But you can set to where the span of temperature change at evap temp sensor, which usually is 2C if factory set.
I set at 0.5C. Since our compressor is not the noisy clutch based compressor, the kick-in of compressor is so elegant...no noise or mechanical jolt.
2C is coldest evap temp setting.
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So I play with the range allowed for compressor to turn off, when and if 0.5C hotter than 2C, it must kick in again.
I can further push the radiator fan to be faster, by tellling HVAC I am using y1234F which is less efficient than R134A.
Interesting, my pre-facelift does not have that IHX line, mine is the traditional one. My car was also built for cold climate I presume as I'm in the midwest snowbelt on the Great Lakes, I travel to the desert and back twice a year, I was driving through New Mexico and it was 118 F, I didn't notice istead of turning up the temperature control, my wife had turned the fan down. my condenser froze up shortly after, I turned off the AC and turned up the fan, about ten minutes later at that outside temperature and 15% humidity it started working again, in my home region the humidity hardly ever goes below 40 and it's common to be 80-90%. That's the only time I've ever had issues.
If you want max cool, you can try change some code:
1. National Version: Hot countries
2. Desert countries: you can YES
3. Effect of solar radiator on regulation of vehicle interior temperature: May be change up 150% or down to 100% to make cooler.
4. Deactivation of additional pump at high coolant temp: change to Yes may help your heater core not too hot.
5. Aircon operating in energy saving mode: Turn it off.
6. ClimaStyle Def: change to High
7. Limitation of fan output at standstill: Change to NO.
That some code I try at 2022, and good cool still now, but I don't have Xentry or Autel now so I can't read code for you but I can remember that.
Interesting, my pre-facelift does not have that IHX line, mine is the traditional one. My car was also built for cold climate I presume as I'm in the midwest snowbelt on the Great Lakes, I travel to the desert and back twice a year, I was driving through New Mexico and it was 118 F, I didn't notice istead of turning up the temperature control, my wife had turned the fan down. my condenser froze up shortly after, I turned off the AC and turned up the fan, about ten minutes later at that outside temperature and 15% humidity it started working again, in my home region the humidity hardly ever goes below 40 and it's common to be 80-90%. That's the only time I've ever had issues.
You had an UN-problem , the humidity is too low, your HVAC is as though as too much power for it.
Before I went deep into the physics aspect of HVAC, I too was focused on temperature only.
For guys like me in the humid tropics, the key is humidity....so I learned.
Latent heat is from Latin meaning hidden heat.
Heat energy which can not be measured temperature wise when water vapor condenses to liquid water or liquid water evaporate to become water vapor.
What we know and measure and see at thermometer it is sensible heat, we can sense this heat.
I think our car HVAC is easy a 12,000 BTU / Hour unit.
If you use fresh air setting at 118F and cool it down to 36F at the evaporator temperature sensor, it only need 0.24 BTU per 1F temperature up/down per pound of air.
If our W212 cabin is say 2,000 liters of air space , that is about 1.22kg weight of air x 2 cubic meters = 2.44kg or 5.37 lbs
You need 118F - 36F = 82F of cooling
Thus 82F x 5.37 lbs x 0.24 BTU = 440 BTU / Hour simplified
When you use recylced air setting, its even less BTU needed.
You have 15% humidity, that is like zero for my case and your HVAC is under-worked, not over-worked if it were 85% humidity.
Latent heat of evaporation is energy intensive. I mean when humidity is high, the HVAC "cooling" power is eaten up by the need to convert water vapor to liquid water
at 970 BTU per pound of water. This one we can not measure the temperature but we can calculate. https://c03.apogee.net/mvc/home/hes/...%20per%20pound.
By right, the evaporator ( you wrote typo as condenser) should not freeze up, when and if the evaporator temp sensor B10/6 is okey and the B82 vehicle interior and humidity/temp sensor is okey too.
B82 is available after Dec 2009 production, as per Code 580 aircond type.
Your air-cond is Code 580 or 581 ?
Code 581 has more sensors, but still the B82 vehicle interior and humidity/temp sensor is for after Dec 2009 production date.
However, low refrigerant fill/level , can also cause evaporator to freeze.
When was the last time your HVAC system went for a good RRR ?
I am sure your evaporator is also very clean...knowing your attention to details.
What blower speed was it when evaporator froze ?
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Do bear in mind, there is no such thing as COLD, COLD is the absence of energy...simplified.
Our HVAC takes away heat to make COLD, that is all it does. It can not inject COLD.
I should have changed the title to : AC deep setting for hot HUMID country with "exhaust gas smelly" traffic jam
But can't edit title, right ?
If you want max cool, you can try change some code:
1. National Version: Hot countries
2. Desert countries: you can YES
3. Effect of solar radiator on regulation of vehicle interior temperature: May be change up 150% or down to 100% to make cooler.
4. Deactivation of additional pump at high coolant temp: change to Yes may help your heater core not too hot.
5. Aircon operating in energy saving mode: Turn it off.
6. ClimaStyle Def: change to High
7. Limitation of fan output at standstill: Change to NO.
That some code I try at 2022, and good cool still now, but I don't have Xentry or Autel now so I can't read code for you but I can remember that.
Thank you
I done almost all above and much more
I said almost is because some settings you advice to change has no benefit for my use case.
If you want max cool, you can try change some code:
1. National Version: Hot countries
2. Desert countries: you can YES
3. Effect of solar radiator on regulation of vehicle interior temperature: May be change up 150% or down to 100% to make cooler.
4. Deactivation of additional pump at high coolant temp: change to Yes may help your heater core not too hot.
5. Aircon operating in energy saving mode: Turn it off.
6. ClimaStyle Def: change to High
7. Limitation of fan output at standstill: Change to NO.
That some code I try at 2022, and good cool still now, but I don't have Xentry or Autel now so I can't read code for you but I can remember that.
I have cleaned the evaporator once, in Cleveland the A/C runs more iin defrost mode than cooling. the fan was turned to zero bars on the control so airflow was minimal, re circulation was not on, but A/C was on and set to 67 F. Also A/C has been checked for function twice over my ownership to make sure it was ok
If you want max cool, you can try change some code:
1. National Version: Hot countries
2. Desert countries: you can YES
3. Effect of solar radiator on regulation of vehicle interior temperature: May be change up 150% or down to 100% to make cooler.
4. Deactivation of additional pump at high coolant temp: change to Yes may help your heater core not too hot.
5. Aircon operating in energy saving mode: Turn it off.
6. ClimaStyle Def: change to High
7. Limitation of fan output at standstill: Change to NO.
That some code I try at 2022, and good cool still now, but I don't have Xentry or Autel now so I can't read code for you but I can remember that.
That is a great list of A/C tweaks.
> About #4 Aux pump:
On non-turbo 276-NA the Bank2 needs all the cooling it can get !! Some ppl run the aux coolant pump non-stop to help cool the head/block. Bank2 always gets heat damaged before Bank1.
Engine cooling should well be kept a priority over the occupants else valves, bores and pistons go South!!
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