Thank you to those who gave me the suggestions within my last thread.

Fast Forward 3 months and I still don't have AC... However after months of researching and professional diagnostics I am getting closer to the solution.

The first problem was first the "improper" butt splice the previous owner had made to the Pressure Switch Sensor Connector, I managed to purchase a new connector and properly splice them via heat shrink splices and secured them with electrical tape.


Original Splices previous owner had made.

Here is the *updated* splices I made I matched the previous orientation of the 3 connections in addition to following the FSM connections.

End result as I secured them the new connector with electrical tape.


Update: This did not fix the solution, so I ended up recently taking it to a professional.

The shop is ran by two well reviewed local mechanics in my area, they concluded that my everything within my AC system was in working condition expect that the AC Compressor/ Relay is not receiving any form of power or signal. They concluded that AC Amplifier/ Climate Control Module was not functioning properly and had to be replaced, they also suggested me to replace my IDPM E/R Module next to my Battery.

They quoted me $2800 with Dealership parts and Labor, my IPDM E/R self test seems to activate my low/high radiator fan speeds and compressor so this does not make believe the IPDM e/r is the problem.

So I went on and purchased a second hand used AC Amplifier part number 277601NN2A, however upon removal and installation my AC Amp is a different part number (27760 1NM6D), it did not fix the solution everything seems to work the exact same besides the AC... Does the AC Amplifier have to be the identical part number or is it safe to assume the AC Amplifier isn't the problem?

My next step is taking an extra look at the AC relay which is not apart of the IPDM e/r model but the module in the driver side, AC Pressure switch, or go ahead and buy the IPDM e/r.

Thanks again, really want to get this fixed, as this SoCal Heat has been killing me, any suggestions help.

 

As long as the amp is from the same car as yours (ie. Coupe for Coupe, sedan for sedan, etc.) then you should be fine with the amp.

Did you download the HAC (Heating & Air Conditioning Control System) section of the factory shop manual (FSM) for your car? I ask as there is a self-diagnostic function built-in that might point you in a more specific direction. I will be straight with you, it is not the easiest diagnostic to navigate, but it should offer some light. At this point, it could be something as simple as a sensor that is out (sunload, ambient, etc.).

The AC relay, if memory serves, is integrated into the IPDM/er as is not serviceable. I would replace this as a last resort with a junkyard donor. Takes all of 5min., if that, to swap out.

 

Hey thanks again for the reply,

My 2012 G sedan has the tech package so I was not sure if compatibility would be an issue, I was going through the part numbers and compatibility via my VIN though infinfits part website. I found out that the only part number that shows compatibility is PN: 27760-1NN3A, However upon removal and installation my vehicle had 27760-1NM6D. Can't guarantee this was the Amp from factory since the car is 12 years old and I am not the first owner, so I might assume it hasn't been touched and will find an identical replacement.

I do have the factory manuals downloaded as I have been looking through them vigorously, I have not had the chance to perform all Diagnostics as you said it does look somewhat difficult to follow. I plan to replace the ambient sensors and pressure sensor since they are the simple and minimal costly parts. ]

- How does the splices I made look, mechanic said they look okay and are functioning properly.

- As far as the IPDM e/r, I see mixed statements how the AC is on driver side function box or inside the IPDM e/r, it makes sense to me that it might be incorporated wihtin the IPDM e/r since its self function test activates A/C,

-My IPDM e/r self test seems to properly activate every component, however does this indicate that there isn't a problem with my IPDM? because the mechanic advised me that the problem is somewhere along the AC Climate Switch to the AC relay - AC compressor, this makes me move towards sensors, pressure switch in particular.
I will however purchase a second hand IPDM for extra measures.

 

One more thing - I found out why the pressure sensor connector may have been replaced,

Mechanic advised me that my vehicle may have been in a small front end collision which makes sense why the connector had to be replaced, this may have damaged other comments within that area -

this broke me since the car is supposedly "clean title" oh well have to move on from it.

 

If, during the IPDM/er self test, that you can visually and audibly.confirm that the magnetic clutch on the compressor is cycling (5x per test cycle) then there is nothing wrong with the IPDM/er.

The issue then points to something further upstream. Something, amp /sensor/ whatever is not "telling" the amp to signal the IPDM/er and "kick" the comoressor on.

 

Yes cycling as in the clutch clicks in and out, I can visually see and hear it. The high and low fans are also roaring as well, so there must be something that isn't signaling to control both AC and Fans.

Ive looking at the FSM electrical diagrams, based off the diagnosis symptoms these are the probable causes the AC Compressor may not be functional accordingly despite activation within IPDM e/r self test - "Unified meter and A/C amp. signal input circuit" - "Can communication signal between unified matter A/C amp. and ECM" - "CAN communication signal between ECM and IPDM E/R"

Cooling Fans not functioning despite being activated by IPDM e/r Self Test - "ECM signal input circuit" - "Can communication between signal between ECM and IPDM e/r"

Since both of these are the primary issues I am facing - the probable cause shared by both is "Can communication between signal between ECM and IPDM e/r"

Im going to do further analysis on the diagrams and see if I can pinpoint the disruption

 

This diagram seems to confirm this probability -

 

Anything is possible but CANBUS failures in these cars are highly rare. Unfortunately, diagnosing CANBUS issues is above and beyond my pay grade. Perhaps others will have ideas.

Did you check for any codes on the car? A good scanner should be able to pull codes for all systems. Any CANBUS errors will list as U1000 or U1001.

Also, the self diagnostic in the amp has the ability to diagnose CANBUS connections internally which display as 50, 51, or 52.

I know if it were me I would jerry-rig the damn compressor and try to get some cold air... this heat wave is killing me so I can only imagine the hell you are dealing with.

 

Yeah man electrical stuff is a pain in the *** I would rather have to deal with paying for a new compressor than this, I haven't found not one forum post or video on A/C amplifiers causing AC issues, its usually the gas gauge scenario.

The A/C Amp seems to act as a communicator from preface climate switches to active these components, everything but the AC works however so it makes believe this isn't a A/C amp issue due its isolation. Im still going to replace it regardless.

I unfortunately don't have an advanced reader to reach these codes.

I was trying to access the Self Diagnosis within the Amp but could not figure it out, I read: turn on ignition (engine) then wait 5 seconds and press OFF switch (which I assuming is the climate off switch?) within 10 seconds.

I tried this and held for 5 seconds and could not manage to access this preface, any ideas on how to do it? I know this process may vary depending if you have the PLASMACLUSTER SYSTEM or not (tech package).
Yeah man I want to try and jump the A/C pressure sensor connector just to feel a bit of cold air.

 

The way I understand it, with radio OFF you start the engine then immediate press and hold the OFF button (climate control panel) for 5 seconds. Once you enter the self-diagnosis the screen will show the graphic shown in the FSM.

From there you navigate with the dial and buttons as indicated.

Can't recommend you "jump" the damn thing but what you do is on you... it is your car...

But something in the electronics is holding you up.

 

Holy **** man! I was able to feel cold ac and see my compressor spin now!

I managed to access the diagnostic feature with the volume **** and setting button I went to climate controls and it instantly kicked the AC and Fans on, cold air felt so good!

It gave me 41 and 51 I have to investigate further, wonder what it can be?

I'll just drive with this diag mode on for now and sacrifice my music lol

Thanks for all the help you've given me man!

 

So the "Confirmation/Adjustment" menu (the 40-click volume thing) actually engaged the compressor? I wonder if there is a "mystery setting" that needs to be toggled for the system to operate normally. I will have to investigate.

EDITED TO ADD: apparently the "CLIMATE CONTROL" menu in the "Confirmation/Adjustment" diagnosis system is a alternative method to engage the AC Amplifier diagnostic system (thats a mouthful). In other words, one can initiate the other. ¯\_(ツ)_/¯

41 is a test of the different blend doors... seems normal.
51 indicates temperature sensors are checked... seems ok.

Take a pic, if you can, of the "Climate Control" menu in the diagnostic that you are referring to. There might be a "mystery setting" that needs to be toggled to get the system "permanently online."

In the interim, enjoy the cold air. A permanent fix can't be far off now. One thing is for sure OP, you have way more patience than I. I'd have taken a sledge hammer to the damn thing by now, lol.

 

This is the display it took me to, as soon as I did the compressor and fans (AC) kicked in. I need to read the FSM to use the driver side climate dial to follow through the diagnosis proccess, I will play with it more tomorrow.

It has to do something with the sensors - pressure switch - ambient - pressure with connector - I plan to replace both, thank god I didn't follow through with that $2800 quote haha

btw this was my first time feeling the cold ac from this car since I got it... 6 months.

 

Update: Seems like I might have found the culprit, and it just might have ended up being a $20 fix...

I ran the Climate control Diagnostics and took record of all sensor temps within the car (keep in mind this is a USA model so this reads in Fahrenheit.
I went followed the process via the FSM for my vehicle.

Measured in Morning Southern California = 74 Fahrenheit.

7. (press defroster once) Ambient Sensor -21
8. (press defroster twice) Check In Vehicle Sensor 87
9. (press defroster a third) Check Intake Sensor 67 (cold start)
10. 51

Based of the findings, the ambient sensor significantly differs from the rest of the sensors, reading at -21.

FSM states, "Low Temperature Protection Control Unified meter and A/C amp. turns compressor ON or OFF as judged by a signal detected by ambient sensor and intake sensor"

Another Mention - I checked any errors recorded by vehicle and recorded these - Bluetooth module connection error 1

Can comm circuit 39

Av comm circuit 39

Switches connection error 2

Sonar connection error 1
Which might have contributed to somewhat of this disturbance.

I will replace ambient sensor and see if it fixes the issue.

 

At least you are making some positive progress and kudos for your persistence.

It would be a blessing if the culprit is the sensor.

Please keep us updated.

As for the COM/ connection errors.. I would just delete the log and see if they recur.

Word of warning: whatever you do, DO NOT select the option to "INITIALIZE SETTINGS." This will erase the AV control unit and render it useless.