Need some help with tuning.

[ls1nova71]

If youre going to use an '05 PCM, then you'll need a 12589462, that should make the 12v A/C request work

[clinebarger]

Originally Posted by ls1nova71

If youre going to use an '05 PCM, then you'll need a 12589462, that should make the 12v A/C request work

Well, I really don't want too waste 2 more credits without knowing a 462 PCM will control the fans with head pressure? Do you have the application for this PCM?

For now, I went ahead & wired in a relay & the A/C works GREAT, 45 degrees out of the center vent, 98 degrees ambient, Head Pressure never got over 250, Low Speed Fans always on, High Speed cycling on & off. Not crazy about not having over pressure protection but, As long as I don't lose a Fan or a Relay.....I should be OK.

[ls1nova71]

Yeah, I hear you on that, and honestly don't know for certain that the fans would also work as I almost always use clutch fans. Sorry I couldn't be of more help.

[Hart_Rod]

Originally Posted by clinebarger

Well, I really don't want too waste 2 more credits without knowing a 462 PCM will control the fans with head pressure? Do you have the application for this PCM?

For now, I went ahead & wired in a relay & the A/C works GREAT, 45 degrees out of the center vent, 98 degrees ambient, Head Pressure never got over 250, Low Speed Fans always on, High Speed cycling on & off. Not crazy about not having over pressure protection but, As long as I don't lose a Fan or a Relay.....I should be OK.

Hopefully I'll have mine running soon and let you know if it works.

[Hart_Rod]

Maybe this will help?

http://www.hptuners.com/forum/showth...press-van-tune

[clinebarger]

Thanks Rob, I will look into that, If I'm reading that right....They are swapping a F-body A/C segment into a Van PCM (Both being a "411" P01 PCM)? Will this work on P59 PCM's would be the question I suppose?

[ls1nova71]

The 411 type PCM (P01) from a van is almost the exact same thing as one from a 99-02 camaro so I'm sure that would work, but from my experience the 411 wont work with the newer P59 blue/green PCM tune. I've personally seen a few bricked PCM's from trying to load newer files into older computers and vice versa. I'll be watching this because I'm curious about the outcome.

On a side note, would it be possible to add a high pressure switch in series with the clutch wire somewhere in a high side line?

[BR3W CITY]

Usually going backwards bricks things, just a generic rule o thumb.
Really good tip when wanting info in one tune (including non HPT) and into another...get Open Office.

You can use a blank spreadsheet and paste-special the data and formatting from the Hpt cells into an external document, then come back and paste into the new tune. You have to be careful that nothing got changed in the translation, but I use this method when making goofy injector scales.

[clinebarger]

Originally Posted by ls1nova71

On a side note, would it be possible to add a high pressure switch in series with the clutch wire somewhere in a high side line?

Not without using a "Piercing Valve" in the liquid line, They eventually leak.
The other option is Crimping a Inline R12 service port on the Discharge hose.....Removing the Hose Assembly is a PITA on this car.

I'm trying too keep "add-on" wiring too a minimum, OCD quirk of mine.

As you can see the only port available is the port for the A/C pressure transducer.

Originally Posted by BR3W CITY

Usually going backwards bricks things, just a generic rule o thumb.
Really good tip when wanting info in one tune (including non HPT) and into another...get Open Office.

You can use a blank spreadsheet and paste-special the data and formatting from the Hpt cells into an external document, then come back and paste into the new tune. You have to be careful that nothing got changed in the translation, but I use this method when making goofy injector scales.

Ok, With the 2005 PCM....The car runs & shifts really weird (Yes I changed the tire height & gear ratio) Changing that back to stock made it shift alot better, But still late & the TCC scheduling is way off.

The question is.......Can I overwrite the 2005 12589463 PCM with the "Tune/Calibration" from the 2004 12586242 PCM??

[BR3W CITY]

Originally Posted by clinebarger

The question is.......Can I overwrite the 2005 12589463 PCM with the "Tune/Calibration" from the 2004 12586242 PCM??

I would just Open Compare File, then open a few of the trans tables and click "differences". That will highlight the cells (or graph area) that are different (in tables that are comparable). Then you can see whats actually functioning differently. Itll highlight green all the areas where differences occur. Then you can view them, and copy the table data from one to the other. Its time consuming, but you'll actually be able to sorta see what the big disparities are. I'm not the most experienced person the planet, but its been my experience that without knowing WHY one worked better than the other, I wouldn't have felt like I solved the problem.

[clinebarger]

Originally Posted by BR3W CITY

I would just Open Compare File, then open a few of the trans tables and click "differences". That will highlight the cells (or graph area) that are different (in tables that are comparable). Then you can see whats actually functioning differently. Itll highlight green all the areas where differences occur. Then you can view them, and copy the table data from one to the other. Its time consuming, but you'll actually be able to sorta see what the big disparities are. I'm not the most experienced person the planet, but its been my experience that without knowing WHY one worked better than the other, I wouldn't have felt like I solved the problem.

Thanks, That helped A LOT! The Copy & Paste feature saved some time for sure!

There is one value I cannot change, Max Trans Pressure....Well, I was able to up it 6 PSI, 90 PSI to 96 PSI. My old tune is set too 130 PSI.

On a side note.....I don't see how this correlates to real world pressures?? My modified pump & large ratio boost valve can bump 225 PSI easy at WOT.

[Super73]

Look at the attached diagram and tell me if this is how your AC fans are wired? They should be a 3 relay set up is using the f-body analog control.


I just went through this with a buddies car. Provided he was using a vintage air unit, the shop that wired it did not have the 3 relay fan set up, no signal from AC to PCM for idle bump, and I had to run a resistor to bypass the pressure switch safety circuit.

This was a great article which I used to help fix his issues: http://www.lsenginediy.com/upgrading...tioning-guide/

It has various pin out assignments, function and even a resistor mod to bypass the pressure switch (which we did in his 73 Camaro).

[clinebarger]

I do have the 3 Relay set-up.

Now that I have a PCM with the correct Hardware, The Fans are functioning correctly with the Pressure Transducer.

I bumped the A/C off Idle table to the same RPM as the A/C on table, I have a Stall Converter so the higher RPM isn't really an issue.

If I'm understanding you correctly, A resistor will make the PCM read a fake fixed value to enable A/C Clutch Relay & Turn the High Speed Fans on anytime A/C is requested? But....Wouldn't that turn the Fans on even without the A/C request because the false refrigerant pressure signal?

My issue right now is.....My 2005 PCM will not accept a 12vdc A/C request.

[BR3W CITY]

Cline I'm bored of fixing A/C problems. Your next post better be about how we need to tune something thats figuratively cool instead of all this literally cool nonsense.

[Super73]

PCM needs 12v to realize AC is on, or requested on. This is what triggers both fans on LOW speed. Fans are in series through a single relay.
Resistor is only there as a bypass for the pressure switch, in the event you can't tie in to it, or it would be redundant like the vintage air.

Originally Posted by clinebarger

I do have the 3 Relay set-up.

Now that I have a PCM with the correct Hardware, The Fans are functioning correctly with the Pressure Transducer.

I bumped the A/C off Idle table to the same RPM as the A/C on table, I have a Stall Converter so the higher RPM isn't really an issue.

If I'm understanding you correctly, A resistor will make the PCM read a fake fixed value to enable A/C Clutch Relay & Turn the High Speed Fans on anytime A/C is requested? But....Wouldn't that turn the Fans on even without the A/C request because the false refrigerant pressure signal?

My issue right now is.....My 2005 PCM will not accept a 12vdc A/C request.

[clinebarger]

Originally Posted by BR3W CITY

Cline I'm bored of fixing A/C problems. Your next post better be about how we need to tune something thats figuratively cool instead of all this literally cool nonsense.

Well, I did post a Trans Pressure question. It seems the consensus is too leave it at 90PSI?

Thanks for the help Brew!

[Hart_Rod]

Any updates on your AC problem CB? Just curious as I'm running a Gen IV Vintage Air system and have a Speartech EFI harness in my Suburban (05 PCM). The harness was wired with a factory trinary switch. Am I going to have the same problem that you are having? Also, I'm using the factory truck compressor that came with the engine, how much oil should I put I in it when I charge it up? Is there anything else I need to consider before charging the system? Thanks in advance. Rob

Rob

[clinebarger]

Originally Posted by Hart_Rod

Any updates on your AC problem CB? Just curious as I'm running a Gen IV Vintage Air system and have a Speartech EFI harness in my Suburban (05 PCM). The harness was wired with a factory trinary switch. Am I going to have the same problem that you are having? Also, I'm using the factory truck compressor that came with the engine, how much oil should I put I in it when I charge it up? Is there anything else I need to consider before charging the system? Thanks in advance. Rob

Rob

I got the AC working, Wired it like shown in Post #20 to reverse the polarity of the 12vdc AC Request & turn the Compressor Relay on anytime the AC is requested, I do not have any sort of "Over Pressure" protection at the moment.

But my Fans work great! And respond too AC Head Pressure even without a valid AC request.

I bumped the AC off Idle Tables up a little (550 vs 525).

All in all.....A/C Request is not a big deal & I wouldn't reinvent the wheel just to get it working, I've been driving my car for 3 weeks & have never turned the A/C off



Your situation is a little different than mine....
Install the Vintage Air Binary in the Drier like normal & run your Compressor wire though it......This will give you High & Low pressure protection.
LOW is OFF @ 28PSIG - ON @ 29PSIG
HIGH is OFF @ 454PSIG - ON @ 369PSIG

For the GM Pressure Transducer, It is 10mm/1.25, You will need to add it into the Liquid Line (#6) somewhere, Vintage Air, Old Air etc. don't have a clue what the h-ell your talking about if you call them. But it is very common in industrial/heavy duty applications, Here is an example....http://www.truckerac.com/achofiforgos.html The Transducer will screw right on.

You will need to drain the oil out of the GM/Denso Compressor.
2 oz. in the Compressor.
2 oz. in the Condenser.
2 oz. in the Evaporator.
6 oz. total.
Use ONLY PAG 46! Required for Denso Compressors!!!

If you do not want to drain the Compressor, The Compressor is used & no oil got dumped......There will be "approximately" 2 oz. of oil in the Compressor.
2 oz. in the Condenser.
2 oz. in the Evaporator.
Keep in mind this is guessing & I do not like it!!

If this is a NEW GM/Denso....It will come charged with 8 oz. of PAG 46. Read the paper work to confirm, Drain 2 oz. out & do not distribute oil anywhere else.

[Hart_Rod]

Originally Posted by clinebarger

I got the AC working, Wired it like shown in Post #20 to reverse the polarity of the 12vdc AC Request & turn the Compressor Relay on anytime the AC is requested, I do not have any sort of "Over Pressure" protection at the moment.

But my Fans work great! And respond too AC Head Pressure even without a valid AC request.

I bumped the AC off Idle Tables up a little (550 vs 525).

All in all.....A/C Request is not a big deal & I wouldn't reinvent the wheel just to get it working, I've been driving my car for 3 weeks & have never turned the A/C off

Your situation is a little different than mine....
Install the Vintage Air Binary in the Drier like normal & run your Compressor wire though it......This will give you High & Low pressure protection.
LOW is OFF @ 28PSIG - ON @ 29PSIG
HIGH is OFF @ 454PSIG - ON @ 369PSIG

For the GM Pressure Transducer, It is 10mm/1.25, You will need to add it into the Liquid Line (#6) somewhere, Vintage Air, Old Air etc. don't have a clue what the h-ell your talking about if you call them. But it is very common in industrial/heavy duty applications, Here is an example....http://www.truckerac.com/achofiforgos.html The Transducer will screw right on.


You will need to drain the oil out of the GM/Denso Compressor.
2 oz. in the Compressor.
2 oz. in the Condenser.
2 oz. in the Evaporator.
6 oz. total.
Use ONLY PAG 46! Required for Denso Compressors!!!

If you do not want to drain the Compressor, The Compressor is used & no oil got dumped......There will be "approximately" 2 oz. of oil in the Compressor.
2 oz. in the Condenser.
2 oz. in the Evaporator.
Keep in mind this is guessing & I do not like it!!

If this is a NEW GM/Denso....It will come charged with 8 oz. of PAG 46. Read the paper work to confirm, Drain 2 oz. out & do not distribute oil anywhere else.

Glad you got yours working the way you want.

I installed the pressure/transducer switch in the high pressure line with the fitting you suggested, but I'm confused. It's a 3 wire switch, so I assumed it was a trinary switch similar to the one you can purchase from Vintage air. Is that incorrect? I wired the a/c "on" signal from the Vintage Air unit to a green wire from my Speartech EFI harness that was labeled a/c request. I just assumed the pressure transducer handled everything else.

As far as the compressor, it's virtually brand new as the motor and transmission only have 10 miles on them. However, neither have been started in 10 years.....sooooo...WWCBD?

Thanks for the info - Rob

EDIT: Perhaps I need to ask more questions and give more info: (keep in mind that I have not started the truck yet....)

1) Is my compressor analog or cycling (its from a 2005/6 Tahoe)
2) I used part number 95018104, is that a pressure switch or pressure transducer?
3) It has 3 wires that go to it, what functions does/should it provide?
4) My EFI harness has a plug that fits into the compressor, has one for the 95018104 switch/transducer that I installed into the liquid line, and an AC request wire that I connected to the Vintage Air a/c request signal wire. So, should I have a high and low protection? Should the fan(s) come on when I turn the a/c on or when head pressure goes high?
5) Did I just totally blow up your thread and do you want me to start another one??????

To throw more fuel on the fire, I found this thread on LS1Tech: http://ls1tech.com/forums/conversion...ector-ecu.html

[clinebarger]

This thread was dead anyway.....Doesn't bother me at all Rob.

It is NOT a Trinary, The Transducer sends a 0-5vdc signal too the PCM & is read as Actual/Real Time A/C Head Pressure, The PCM will control the Fans per Pressure & disable them above a certain speed, You can change all these settings with HPT's.

A '05 GMT800 P59 is "Serial Cycling" from the factory, Meaning the HVAC Control head not only sends a Serial A/C Request, But can also send A/C Clutch Cycling Requests over the Serial Data Line as well (Low Pressure Cycling) because the Low Pressure Switch is wired to the Control Head not the PCM. High Pressure Cut-Out is based on Transducer Readings.

The thread you linked too mentions Van PCM's, They are Analog Cycling, The Control Head sends a 12vdc A/C Request, A simple High Pressure cut out switch is wired inline & interrupts the Request if pressure is too high. The Low Pressure Switch is wired to the PCM directly.

Analog.....Was used on 4th gen F-Bodies, No Low Pressure Switches as the Compressors are a Variable Design, PCM can turn the Compressor off is Transducer/AC Head Pressure is too high.

Serial.....Corvettes, CTS-V etc.


All the above "Settings/Type Fitted" cannot be actually changed with HPT's, It's Hardware......Tuning Software has no effect.

The ONLY PCM I know of that accepts a 12vdc A/C Request & Control the Fans via Transducer input is "0411" PCM's from '99-'02 F-Bodies But those won't work with our DBW set-up.

Unless John Spears has figured out how too do this with a GMT800 P59 PCM, The 12vdc you have on the A/C Request wire will not prompt the PCM too ground your Compressor Clutch Relay (Did John flash your PCM?)

Back to the Van P59's, They do accept a 12vdc A/C Request, And will ground the A/C Clutch Relay (With the Low Pressure Input grounded), But WILL NOT operate the Fans per Transducer Input!

'03 & '04 GMT800 P59's do not accept a 12vdc A/C Request nor will they Operate the Fans per Pressure.

'05, '06, & '07 Classic GMT P59's do not accept a 12vdc Request, But WILL operate the Fans per Pressure.

[clinebarger]

Rob, Have you tested the A/C Request? While watching A/C Request PID on your scanner, Turn the Vintage Air on & see if it changes from "No" to "Yes". Check for 12vdc on the Request Wire if still "No".

If we can't get a valid Request, No need in leaving it wired the way it is now.

Recap if the Request doesn't work out.....

Vintage Air Compressor Clutch wire too the VA Binary, Binary too the Compressor. Will provide High & Low Pressure protection.

The Transducer & PCM will provide Fan Control as needed.

Up the Base Idle as needed, This can get weird with a stock stall converter upon decal to a stop. The PCM's seem to "learn" & act right after a few miles. I'm sure a good tune could correct this.

Your Compressor should have around 2 oz in it, This is just an average based on my experience servicing GMT800 Trucks.
If I decided to go this route, I'd be concerned about using Too Much Oil! And would add 3 to 3 1/2 ounces, The Denso Compressor is VERY good design & can cope with a little less oil, Where too much oil will affect A/C performance.....More so with aftermarket units.

I would (If it were mine) Drain & Flush the Compressor. Use High Volatility/Flammable/No Residue A/C Flush, The good stuff, Kills baby Seals & such. While turning the Compressor....Flush all the residual oil out.

Add 6 ounces of PAG 46 too the Compressor, After installed, Spin it at least 20 times. Deep Vacuum for at least 12 hours.

Start with 28 ounces of 134a, You will probably end up with 2-2.25 pounds to get maximum chill.

[Hart_Rod]

Originally Posted by clinebarger

Rob, Have you tested the A/C Request? While watching A/C Request PID on your scanner, Turn the Vintage Air on & see if it changes from "No" to "Yes". Check for 12vdc on the Request Wire if still "No".

If we can't get a valid Request, No need in leaving it wired the way it is now.

Recap if the Request doesn't work out.....

Vintage Air Compressor Clutch wire too the VA Binary, Binary too the Compressor. Will provide High & Low Pressure protection.

The Transducer & PCM will provide Fan Control as needed.

Up the Base Idle as needed, This can get weird with a stock stall converter upon decal to a stop. The PCM's seem to "learn" & act right after a few miles. I'm sure a good tune could correct this.

Your Compressor should have around 2 oz in it, This is just an average based on my experience servicing GMT800 Trucks.
If I decided to go this route, I'd be concerned about using Too Much Oil! And would add 3 to 3 1/2 ounces, The Denso Compressor is VERY good design & can cope with a little less oil, Where too much oil will affect A/C performance.....More so with aftermarket units.

I would (If it were mine) Drain & Flush the Compressor. Use High Volatility/Flammable/No Residue A/C Flush, The good stuff, Kills baby Seals & such. While turning the Compressor....Flush all the residual oil out.

Add 6 ounces of PAG 46 too the Compressor, After installed, Spin it at least 20 times. Deep Vacuum for at least 12 hours.

Start with 28 ounces of 134a, You will probably end up with 2-2.25 pounds to get maximum chill.

Will check this later this evening. In the meantime, found this thread on HPTuners: http://www.hptuners.com/forum/showth...system+options

[Hart_Rod]

OK, I checked HPTuners and no a/c request when I turned the AC on via the Vintage air switch, . However, I did verify that the compressor clutch is receiving power when I turn the system on.

My setup:
OPERATING SYSTEM:
12587811

AC HARDWARE SETTINGS:
Recirculation fitted: #2 fan
Type Fitted: Serial

Does this look correct? It's what was in the factory tune when I first read the computer. I think at this point, I may need to wait until the truck running before I can check out the operation of the entire system.

[clinebarger]

Not sure how your harness is wired, But obviously not like factory.....

I'm going to guess they branched the A/C Request wire to feed the PCM (Green(C2) Pin 17) & the Compressor Clutch? You can OHM Pin 17 to the Clutch power wire to confirm my suspicions.

I made a mistake in my earlier post, A '05 GMT800 is Serial, Serial Cycling would have a Low Pressure Switch wired to the PCM.

Set it to Analog & retest.....If no go, Set it too Analog Cycling. If we can just get a Valid Request....Everything else will fall into place.

You need too redo your A/C pressure vs Fan Enable settings, The way they are now is for Dual 15" Fans that come stock on '05 & up GMT800's.....They move a ton of air even at half speed. I doubt your aftermarket fans pull close to the same CFM.

Here is how mine are set......

[Hart_Rod]

Originally Posted by clinebarger

Not sure how your harness is wired, But obviously not like factory.....

I'm going to guess they branched the A/C Request wire to feed the PCM (Green(C2) Pin 17) & the Compressor Clutch? You can OHM Pin 17 to the Clutch power wire to confirm my suspicions.

I made a mistake in my earlier post, A '05 GMT800 is Serial, Serial Cycling would have a Low Pressure Switch wired to the PCM.

Set it to Analog & retest.....If no go, Set it too Analog Cycling. If we can just get a Valid Request....Everything else will fall into place.

You need too redo your A/C pressure vs Fan Enable settings, The way they are now is for Dual 15" Fans that come stock on '05 & up GMT800's.....They move a ton of air even at half speed. I doubt your aftermarket fans pull close to the same CFM.

Here is how mine are set......

Chris, I changed the fans/pressure settings as you suggested and then tried the Analog/Analog cycling and no go on the AC request signal. I'm starting to think that the green "ac request" wire in the EFI harness is just a pass through that Speartech put in the harness. I do know it will light up a test light at the compressor plug when I trigger the clutch via the Vintage Air controls. I'll try to ohm it out tomorrow. What readings should I expect, "0"? Thanks again for the help.

Rob