Nissan Leaf A/C compressor 92600-3NF0A

[johu]

For the Audi A2 conversion I will be using the left over A/C compressor from the Gen2 Leaf motor stack (probably the same for all Leafs). Here is what I have found out so far

Logic connector: - 1 2 - 3 - (3 pins blanked) 1 = GND, 2 = 12V, 3 = LIN

LIN baudrate is 19200

I have found data to be returned on id 17, 33, 35, and 38

I connected some low voltage to the power input but never saw any of the messages change.
Bit 16 of id 17 goes high as soon as you try to send on any of the read-only ids but also on id 60. Maybe that is the control message? Will need to monitor the other data as well. Will keep updating here.

UPDATE:
listens to messages 32, 34, 59, 60.
When 32.0.0 (byte 0, bit 0) is set to one, message 33 becomes alive. Shows undervoltage flag in 33.2.6, voltage in 33.7. Must be multiplied by 2 to obtain bus voltage.

[Tremelune]

Delighted to see work being done here...I have a Leaf compressor and dreams of AC, and it seems silly to buy more parts for this thing...

[johu]

Alright, some more insight
Byte 2 (not bit 0) of message 17 certainly flags LIN errors. When all is good its value is 0xF8, in case of error 0xF9. So bit 0 of byte 2.
It also signals errors if you send a control message with wrong length. With the help of that I found that it seems to listen to messages 32, 34, 59 and 60. I haven't found an effect of 59 and 60 yet. All control messages need to be 8 bytes long
When message 34 is send, message 35 changes its content from all zeros to 03 7f 00 11 ff ff ff ff - no idea what it means yet

More interesting is message 33. It changes its content when message 32 is sent with only the first bit set. If you set any other bits, it returns to all zeros.
Byte 2, bit 6 is one when there is too little voltage on the high voltage input. Not quite sure what the threshold is. Maybe about 100V, 170V is enough and thats as low as my transformer goes.
Byte 7 is proportional to the bus voltage, namely udc/2. It doesn't become 0 when there is no voltage but settles somewhere around 90V.
Byte 6 also sometimes changes but I don't know what it means yet. Settles at various values and slightly changes when HV is turned on. Maybe current?

Apart from that I haven't gotten it to spin yet, but then it's just sitting on my desk with no gas in it. So maybe that's as far as I can get for now.

[Alibro]

Where I live in Ireland heating is more important than cooling but ac would be very nice.
I have all the bits from my donor car so watching with great interest.

[Robert]

Where I live in Ireland heating is more important than cooling

Reverse the flow of refrigerant and your AC system makes heat

Apart from that I haven't gotten it to spin yet, but then it's just sitting on my desk with no gas in it. So maybe that's as far as I can get for now.

I doubt it's going to run without any refrigerant in it.

How many refrigerant lines does that thing have coming off the assembly? Nissan built it as a heat pump and all the reversing valves and such might be built into the lump.

[Tremelune]

Heated seats go an extraordinarily long way. It may not be enough sub-freezing, but they cut down cabin heating power substantially.

[Alibro]

Heated seats go an extraordinarily long way. It may not be enough sub-freezing, but they cut down cabin heating power substantially.

Agreed. I just bought a Freelander SE that has heated seats and a heated windscreen. I plan to move everything from my test mule to this car when I have it all working.

[Renegate2020]

A very interesting topic. Something to start the air conditioner compressor I would get.

[johu]

If anyone has a Leaf and can listen to the LIN traffic with compressor on and off that would be helpful

[dimonlipko]

I run leaf compressor. It need only one frame to run ID 0x3b 0xb3, 0x05, 0x00, 0x90, 0xff, 0x00, 0x00, 0x00

0 and 1 bit - AC power

I dont revers what compressor answer. I think that must be information about RPM, voltage, current.

[raine]

I run leaf compressor. It need only one frame to run ID 0x3b 0xb3, 0x05, 0x00, 0x90, 0xff, 0x00, 0x00, 0x00

0 and 1 bit - AC power

So you succesfully control the compressor? Could you pls share a sample syntax in code in detail. I am a total newbie with Lin and this would get me a fast start to it.

Thanks.

[delgadb2]

It sounds like you need to send frame ID 0x3b then fill the data frame with
0xb3, 0x05, 0x00, 0x90, 0xff, 0x00, 0x00, 0x00
LIN is funky if youre used to CAN. its a master/slave setup. The more PC way to phrase that and according to recent standards is Commander/Responder.
Anyhow. The Master has a schedule table that sends out the frame IDs periodically. Just the frame ID thats it! then the other devices will fill the data portion of the frame they are programmed to publish. Typically the master will send the frame ID for the command message will respond to itself with the commanded value(compressor set speed) and then the slave devices listen to that response and implement it. this is what prevents collisions. Then the master will publish the Frame ID for the slave to fill with the response message (measured speed/status) there is no back and forth communication.
so, you would send Frame ID 0X3B then respond to it with 0xb3, 0x05, 0x00, 0x90, 0xff, 0x00, 0x00, 0x00 as the data portion of frame 0X3B this is the command message to that the ac compressor is programmed to listen to. I imagine there that data includes an ON/Off request and a speed command. you would then need to send the Frame ID for the compressor status the compressor would see that ID and fill the data bytes with relevant info.

[johu]

ok, now I got it. 0x3b is 59 decimal. So it seems it's hacked then
Test will probably be a few month ahead as I plan this to be the last thing to do on the A2 conversion

[johu]

You can study my untested LIN code here: https://github.com/jsphuebner/stm32-car ... r.cpp#L290
Still haven't understood which exact bit in the 0x3b messages enables or disables the compressor

[raine]

0 and 1 bit - AC power

Wow. Got it spinning with the single frame only. Thanks for sharing. Could you pls explain this 0 and 1 bit reflection to ac power, how to use? Many thanks!

[dimonlipko]

Dont remember, but in my code i have 3 power:
b[0] = 0xb9; b[1] = 0x05; //1kwt
b[0] = 0xb9; b[1] = 0x12; //2kwt
b[0] = 0xb9; b[1] = 0x16; //3kwt

I see in leaf diagnostic information by ac compressor. It send to car voltage, rpm, internal temp, interlock state, and power. Maybe in futere i decode this date in lin.

[et0]

Hi all, just putting it on here in case anyone else researches the same thing:

Denso 92600-5SA1A

I think this is the compressor from the later "heat pump" version. It has the same type of connector, but I don't have success sending it the LIN message mentioned in the thread above.

If anyone has some experience with this one please jump in!

IMG_4048.jpg (53 KiB) Viewed 13076 times

[dimonlipko]

Hi all, just putting it on here in case anyone else researches the same thing:

Denso 92600-5SA1A

I think this is the compressor from the later "heat pump" version. It has the same type of connector, but I don't have success sending it the LIN message mentioned in the thread above.

If anyone has some experience with this one please jump in!

IMG_4048.jpg

You need to find leaf with same compressor, and make lin bus log.

[abetanco]

Hello, I have the same model AC Compressor and a UART to LIN transceiver based on NXP's TJA1021 LIN Transceiver. I was planning on using the code you posted, and implementing it on my Arduino Mega, to test my compressor. Thank you for sharing it. What LIN Transceiver did you use, and did you use any special software to read and send messages, or was this accomplished solely with the microcontroller and serial monitor?

I also noticed that Microchip Technologies sells a LIN Analyzer with software, but I'm not sure that's necessary. Have you used this one, or a similar one?

Any other specifics on equipment you may have used would be helpful to me.

Thank you!

[abetanco]

Hello again, I was able to get my compressor to spin using Frame ID 0x3B followed by 0xB3 0x05 0x00 0x90 0xFF 0x00 0x00 0x00. I used a Microchip Technologies Lin Analyzer connected to an old laptop, then sent the message continuously. I noticed the compressor only spines using the ENHANCED checksum (not classic), which I believe is from LIN Specification Package 2.x.

I plan to use a small microcontroller with a LIN transceiver (MCP2025) to send UART messages at the right bit lengths to control the compressor in my EV conversion, which has been complete and driving since December last year, but very hot here in Florida (USA).

Given the above, would anyone be able to give me some advice on the following?

1. If UART signals are generated at the correct lengths and looped continuously, controlled on or off by a button, can they be passed through a LIN Transceiver (such as the one mentioned above) and understood by the compressor? I plan to try this, but would appreciate any advice anyone has.

2. Would someone explain a little about how you were able to listen/sniff/snoop/decode the LIN messages to arrive at the Frame ID and data bits above? Did you use an aftermarket LIN Analyzer (like the one I used) and a PC program, or did you make your own with the STM32 microcontroller? Any tips would be appreciated.

Thank you all for figuring this out, I'd like to learn how you did it.

[manny]

1. Probably. or change the message depending on a input signal on/off

2. use a LIN transceiver and connect the output to a logic analyser like a saleae logic (clone)

[abetanco]

1. Probably. or change the message depending on a input signal on/off

2. use a LIN transceiver and connect the output to a logic analyser like a saleae logic (clone)

Thank you! I will try this out and let you know what I find.

[abetanco]

Hello all, I was able to write some code for my Arduino Mega to use UART to mimic LIN, and the compressor ran directly from the microcontroller. Although I tried to directly use frame address 0x3B, the compressor didn't seem to run. Once I added the two parity bits (Bits 6 and 7 of the frame signal, each with value of 1), the "Protected Identifier" (frame address of 6 bits plus parity of 2 bits) becomes 0xFB. This is documented in LIN Specification 2.2A. Using the protected idenitifier of 0xFB allowed the compressor to run from the Arduino Mega. I think my LIN Analyzer software was automatically doing this, and I didn't figure it out until I reread the LIN Specification 2.2A. If anyone wants to see my simple code for the Arduino Mega, I'd be happy to post it.

Thank you again to all on this thread for hacking this compressor! I couldn't have done it without you.

[abetanco]

1. Probably. or change the message depending on a input signal on/off

2. use a LIN transceiver and connect the output to a logic analyser like a saleae logic (clone)

Thank you for the Saleae logic idea, it worked great. I was able to confirm the frame address I was sending (previously I only had my oscilloscope, and it does not have a logic analyzer built-in). Both your comments were helpful to me, so thanks again.

[joeflickers]

Hello all, I was able to write some code for my Arduino Mega to use UART to mimic LIN, and the compressor ran directly from the microcontroller. Although I tried to directly use frame address 0x3B, the compressor didn't seem to run. Once I added the two parity bits (Bits 6 and 7 of the frame signal, each with value of 1), the "Protected Identifier" (frame address of 6 bits plus parity of 2 bits) becomes 0xFB. This is documented in LIN Specification 2.2A. Using the protected idenitifier of 0xFB allowed the compressor to run from the Arduino Mega. I think my LIN Analyzer software was automatically doing this, and I didn't figure it out until I reread the LIN Specification 2.2A. If anyone wants to see my simple code for the Arduino Mega, I'd be happy to post it.

Thank you again to all on this thread for hacking this compressor! I couldn't have done it without you.

hi,are you able to share the Arduino sketch,I also have the dream to have AC running using the leaf compressor,i have 3 compressors sitting down in my garage,im also wondering how you run and monitor the compressor pressure,how do you accomplish this?thanks