A/C request fix works for me hope it helps others.
06-05-2014, 06:13 PM
#21
I'm going with the express PCM and calibration because it allows me to use my existing DBC setup and my existing wiring from my 0411 setup. The reason for the switch is to be able to have flex fuel capabilities as well as a 3 bar speed density operating system for my turbo setup.
06-05-2014, 06:16 PM
#22
Not quite. The OS's are different the 04 Vette, 04 GTO, are different. The 05 CTSV and Express van's can have the same OS. The pressure sensor or switch along with the fan setup are controlled by the OS. All OS's have settings to change them. The real difference between the PCM's is if they have the IAC driver or not. Be careful if you decide to upgrade. The 243, 463, and 802 have the IAC drivers but the 242, 462, and 801's do not. If you are running a DBW setup then it does not matter. Other than that they are basically the same other than speed and memory. Note you can go to a newer PCM from the 99-02 as a plug and play but you have to change the O2 sensor wiring if you go the other way.....
Here is the reason why I prefer the newer OS's and PCM's over the 411 which is by far the most popular...
http://www.superchevy.com/how-to/0704gm-factory-pcms/
Here is the reason why I prefer the newer OS's and PCM's over the 411 which is by far the most popular...
http://www.superchevy.com/how-to/0704gm-factory-pcms/
06-05-2014, 09:32 PM
#23
Guys,
There is no reason to make A/C so complicated.
Why bypass the pressure switch when you can grab the fitting for less than 15 bucks and have it installed in the A/C line that you will have to have made anyway?
WE CAN DO HARD WIRED A/C REQUEST EVEN ON THE DBW BLUE/GREEN PCM
This requires that we will need to do the wiring and the tuning.
My point being, that the pressure switch opens up a ton of options for your Fans and Idle. Not just idle bump or forcing one fan on. Im talking Idle controls versus pressure and fan staging.
Bill
There is no reason to make A/C so complicated.
Why bypass the pressure switch when you can grab the fitting for less than 15 bucks and have it installed in the A/C line that you will have to have made anyway?
WE CAN DO HARD WIRED A/C REQUEST EVEN ON THE DBW BLUE/GREEN PCM
This requires that we will need to do the wiring and the tuning.
My point being, that the pressure switch opens up a ton of options for your Fans and Idle. Not just idle bump or forcing one fan on. Im talking Idle controls versus pressure and fan staging.
Bill
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06-06-2014, 11:04 AM
#24
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Whats nice about PCM fan control and pressure is the fans can be controlled via the pressure, and at cruise they can be shut off, kicked on is pressure demands it etc etc. Having the fitting added for the pressure switch is pretty easy and can be done by most any shop that can make lines.
06-06-2014, 11:52 AM
#25
Whats nice about PCM fan control and pressure is the fans can be controlled via the pressure, and at cruise they can be shut off, kicked on is pressure demands it etc etc. Having the fitting added for the pressure switch is pretty easy and can be done by most any shop that can make lines.
06-06-2014, 02:52 PM
#26
It is a combination of wiring and programming. To my knowledge we are the only company offering This opting for the DBW applications. So for now, we must perform the wiring and the programming.
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www.bp-automotive.com
1-888-467-4491
Standalone LS Swap Harnesses IN STOCK!
LSX, LTX Stand alone swap harnesses. S10 LSX conversion PLUG AND PLAY harnesses, 24x conversion PLUG AND PLAY harnesses. LT1 to LSX PLUG AND PLAY Harnesses.
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06-18-2014, 10:39 AM
#27
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05-14-2024, 05:30 AM
#28
On The Tree
So I'm going to add my findings to this.
I've wired up mine as per the OP posted diagram, but it's not working. I believe This is because in the tune I have the "Type Fitted" set to "analog" instead of "Analog Cycling" so I will try this and see if that resolves the issue.
I've checked in HPTuners and the resistor section works as intended, my issue is that the PCM will detect when the A/C clutch is activated by manually sending 12v to it, but the Red#43 pin won't send the ground to the relay when the 12v request is sent.
For those asking why someone would do this instead of "just buying the $15 fitting", I have not been able to find a single place that sells the correct part needed to install this, i.e. a male fitting for coupling the LS1 a/c pressure sensor to the thread, and then crimping to the #6 high hose.
The only ones available for ATCO#6 line are the 1/4" R12 thread for the binary switch.
I couldn't even find a 1/4" trinary switch to manually wire for cutoff for high and low pressure.
Mine was a completely custom system so I had to make all the lines from the parts available, and although it doesn't help being in Australia, even ordering from US I couldn't find them.
My plan if the tune setting doesn't work is to cut the Red#43 relay grounding wire and just replace the 12v request switch I have for the cold a/c with a DPDT switch and also send the ground to the relay to manually trigger the clutch relay.
This will at least kick the compressor in and the PCM will raise idle and use the RPM and TPS settings to control the compressor.
I've wired up mine as per the OP posted diagram, but it's not working. I believe This is because in the tune I have the "Type Fitted" set to "analog" instead of "Analog Cycling" so I will try this and see if that resolves the issue.
I've checked in HPTuners and the resistor section works as intended, my issue is that the PCM will detect when the A/C clutch is activated by manually sending 12v to it, but the Red#43 pin won't send the ground to the relay when the 12v request is sent.
For those asking why someone would do this instead of "just buying the $15 fitting", I have not been able to find a single place that sells the correct part needed to install this, i.e. a male fitting for coupling the LS1 a/c pressure sensor to the thread, and then crimping to the #6 high hose.
The only ones available for ATCO#6 line are the 1/4" R12 thread for the binary switch.
I couldn't even find a 1/4" trinary switch to manually wire for cutoff for high and low pressure.
Mine was a completely custom system so I had to make all the lines from the parts available, and although it doesn't help being in Australia, even ordering from US I couldn't find them.
My plan if the tune setting doesn't work is to cut the Red#43 relay grounding wire and just replace the 12v request switch I have for the cold a/c with a DPDT switch and also send the ground to the relay to manually trigger the clutch relay.
This will at least kick the compressor in and the PCM will raise idle and use the RPM and TPS settings to control the compressor.
