TipsyMcStagger

iTrader: (1)

My swap is an LS2 with an E40 PCM. Unlike the older ECM's, the E40 AC request signal is generated by the BCM, which I'm not using. I bought a custom Ardunio module that will provide the necessary serial information to the E40. The Arduino module is effectively a "stand in" for the original BCM. This should allow the E40 to fully control the fan, boost the idle, provide high RPM compressor cutout, etc. In other words, it should be 100% as it was in GM factory application.

With all of that said, I will need to install a GM pressure switch somewhere in the system. In my notes, I have written that the GM pressure switch (part# 92145716)? should be installed in the line running between the drier/accumulator and the condenser. Is this correct? If so, is this the only pressure sensor/switch needed?

I'd like to have lines made this week and I need to make sure I'm making all of the necessary accommodations.

Thanks!

TipsyMcStagger

iTrader: (1)

And now I'll complicate things a bit; although my E40 and engine came out of a 2006 GTO, I had the PCM flashed to a 2006 SSR OS (so I can have cruise control). I have AllData acess for both the 2006 GTO & SSR.

I'm surprised to see that the pressure sensors are different parts numbers. The GTO sensor is 92145716 and the SSR is 22664328. I found an old post - quoted below - which indicates that 22664328 was used '98-'02 and 92145716 was used in '06 and later, but given that the SSR is an '06 and uses 22664328, that doesn't seem to be entirely accurate.

Does anyone know what the differences are between the two sensors? I'm inclined to use the part number that aligns with the OS flash that's on my PCM (SSR OS) but I'm really just guessing.

EDIT: According to Rockauto, GPD 1711438 is interchangeable for both 92145716 & 22664328.




And why stop there with the convoluted questions? I also noticed in AllData that the SSR has an additional sensor not used on the GTO; a "Pressure Cycling Switch" part# 89040362. I can't find this switch anywhere in the schematic.

Any idea what it is and if I need to worry about it?

69 Ghost

No cycling switch because the compressor is a variable as opposed to a fixed.
A pressure sensor is a pressure sensor is a pressure sensor. As long as it works why are you worried about the part number? GM supersedes numbers all the time.

TipsyMcStagger

iTrader: (1)

Ahhh. That makes sense. I guess there's a different type of compressor in the SSR than in the GTO.

That's just the thing; I wasn't sure if a pressure sensor is a pressure sensor. I came across the chart below which illustrates how different sensors have varying voltages vs. detected PSI. But I guess many of these three-wire GM senors are the same with regard to specifications.

Thanks for the feedback. Always appreciated.

69 Ghost

If you changed your OS and you are using the original accessories then you will need to make sure you change your compressor type in the OS.

TipsyMcStagger

iTrader: (1)

I'm using a Sanden SD7B10 compressor, which is fixed displacement. The OE F-Body compressor I was originally planning to use and the the OE GTO compressor are variable displacement.

I'm guessing the OE SSR system used a fixed displacement compressor? If so, will the SSR OS settings be okay as they are for use the fixed displacement Sanden compressor?

Jones'n

Because "BMW Guy" has to overthink everything until his German engineered world can finally be at peace.

TipsyMcStagger

iTrader: (1)

Most people learn by doing. This is my first time "doing" this kind of thing.

I don't feel the need to apologize for my lack of experience. I assume you weren't born knowing all of the answers either.

I appreciate the input from those who are here to help.

rickpaw

I don't know about GM's ECU/OS, but in Dominator ECU, we need to plot the curve for the pressure sensor (volt vs pressure), so knowing the part number and its corresponding voltage/pressure curve helps.

TipsyMcStagger

iTrader: (1)

That was the crux of my initial inquiry; whether the voltage/pressure curve varies between GM part numbers. Thanks for providing the proper nomenclature.

If the SSR came factory with a fixed displacement compressor and had a pressure cycling switch as part of that system, will I have issues running the Sanden fixed displacement compressor with the SSR OS without the pressure cycling switch?

Is there a setting in the OS that can/needs to be adjusted?

69 Ghost

There are pressure sensor settings for fan on/off, etc but basically the system is 0-5 volts and it's scaled at 0-500psi at least that's what I remember when logging the data. The on/off pressures are a little different from a variable and a fixed but it will work fine. What I have found is that the pressure sensor really never turns on the high fans because they are set in the 325-350psi region and if you have dual with a low speed it's enough airflow to do the ac job no matter how hot it is. Secondary to that is if you modify the high fan temps to say 210-215 it will most likely kick those on from the coolant temp first.

Put a cycling switch in if you have a fixed compressor.

TipsyMcStagger

iTrader: (1)

My plan is to use a single Volvo fan with the two speed Volvo relay, controlled by the E40 PCM.

The Sanden SD7B10 I'm using is a fixed displacement compressor. Seemingly, the OE SSR compressor was fixed displacement as well.

Where in the system would I place the cycling switch? I've looked at the SSR wiring diagram and I don't even see the pressure cycling switch depicted.

Thanks very much for the continued discussion.

69 Ghost

You are asking a question that I cannot answer because you have not provided the car that the motor is going into. You have only provided the motor info.

TipsyMcStagger

iTrader: (1)

I'm sorry. It's going into an E36 BMW. 1998 328iS.

The factory BMW compressor was a Denso 10PA17C, which I believe is also a fixed displacement compressor.

The label on the Denso compressor has a Low Side and High Side pressure rating of 1.67 MPa and 3.53 MPa, which equate to approximately 242 PSI & 512 PSI, respectively.

There is a high-pressure switch in the original BMW system (that I'll replace with the GM pressure sensor) but I don't see a cycling switch anywhere.

I have a custom made Arduino module that will send the required serial A/C request signal to the E40, so the goal is for the E40 to have full control of the A/C system and fans.

69 Ghost

Based on my experience with BMW's it probably has a TXV valve. If so it will have a temp probe on the evaporator that controls the cycling. You need to find the wiring for the Beemer and tie into that as needed.

TipsyMcStagger

iTrader: (1)

Okay. Thanks. The car is at the hose shop right now. The two other builds E36 builds I've seen online that used Sanden SD7 & 508 compressors are not using anything other than the GM trianary switch. They are using GM PCM's other than the E40 but they are reportedly functioning properly.

UND_Sioux

Can you tell me where you got that module? I'm having a similar issue. Thanks.

TipsyMcStagger

iTrader: (1)

It was custom made by a member of the BMW forum, username Thaniel.

EDIT: I think he's @Thaniel on LS1Tech as well, but I don't think he's very active here.

69 Ghost

That work was taken over by a member here PeteS160

TipsyMcStagger

iTrader: (1)

Interesting. I didn't know that. Is there a thread about it somewhere? Is Thaniel no longer doing any Arduino work?

I never followed his E46 threads much but I know he was heavily involved in blazing the trail for CAN bus solution in those swaps.