Nissan Leaf A/C compressor 92600-3NF0A

[abetanco]

Good morning, yes, I'd be happy to. sorry for the late response. Give me a couple of days to organize a response and I'll share the code. Hopefully I can answer any questions you have. The main idea of the code is to continuously (once every 200 ms or so) send a message to the compressor, and make the message look like a LIN signal, even though it is a UART signal. Code coming up soon...

[abetanco]

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

Good morning, yes, I'd be happy to. sorry for the late response. Give me a couple of days to organize a response and I'll share the code. Hopefully I can answer any questions you have. The main idea of the code is to continuously (once every 200 ms or so) send a message to the compressor, and make the message look like a LIN signal, even though it is a UART signal. Code coming up soon...

[joeflickers]

Good morning, yes, I'd be happy to. sorry for the late response. Give me a couple of days to organize a response and I'll share the code. Hopefully I can answer any questions you have. The main idea of the code is to continuously (once every 200 ms or so) send a message to the compressor, and make the message look like a LIN signal, even though it is a UART signal. Code coming up soon...

Excellent.. My compressor is different but from Johus but it's from a gen 2 nissan leaf.. I'll share pictures and possibly assist me in knowing the pinout too

[JeffP93]

This is awesome. I'm just starting my conversion and have everything sorted except for controlling the leaf compressor.

Very interested in the Arduino code you've got working.

[tom91]

Give me a couple of days to organize a response and I'll share the code.

Do you have part numbers for the compressor you have running? I am tempted to look into the 926005SA1B as these are going cheap in the UK

[joeflickers]

Excellent.. My compressor is different but from Johus but it's from a gen 2 nissan leaf.. I'll share pictures and possibly assist me in knowing the pinout
I Have two compressors with part numbers 9192000 AND 9192001

[abetanco]

Hi All,

I think my compressor is a Denso ES27C, but the tag is hard to read.

The code is as follows. Basically, it is a way to make the Arduino send a UART message that looks like a LIN message. Let me know if you have any questions!

****BEGINNING OF CODE****

#define EVAP_VOLTAGE_7_PIN 7

int brklen = 14; // 13 bits + 1 bit for break delimiter
uint8_t sync = 0x55;
uint8_t addr = 0xfb;
uint8_t buf[8] = {0xb3, 0x00, 0x00, 0x90, 0xFF, 0x00, 0x00, 0x00};
uint8_t cksum = 0xb7;
int baud = 19200;
uint16_t brk = (brklen*1000000/baud); // brk in microseconds

void setup() {
pinMode(18, OUTPUT);
pinMode(EVAP_VOLTAGE_7_PIN, INPUT_PULLUP);
Serial.flush();
Serial.begin(baud);
Serial.print(brk);
}

void loop() {

int evap_voltage_7_status = digitalRead(EVAP_VOLTAGE_7_PIN);

while (evap_voltage_7_status == HIGH) {
buf[0] = 0xb3;
buf[1] = 0x0c;
cksum = 0xb3;
} else {
buf[0] = 0xb2;
buf[1] = 0x00;
cksum = 0xc1;
}

pinMode(5, OUTPUT);
digitalWrite(5, HIGH);
digitalWrite(18, LOW);
delayMicroseconds(brk); // For 19,200 Baud, brk should be 677us for brklen of 14us
// or 729us for brklen of 13us.
digitalWrite(18, HIGH);
Serial1.begin(baud);
Serial1.write(sync);
Serial1.write(addr);
Serial1.write(buf[0]);
Serial1.write(buf[1]);
Serial1.write(buf[2]);
Serial1.write(buf[3]);
Serial1.write(buf[4]);
Serial1.write(buf[5]);
Serial1.write(buf[6]);
Serial1.write(buf[7]);
Serial1.write(cksum);
delay(200);
Serial1.end();
Serial.println(buf[1]);
Serial.println("Evaporator On");
}
buf[0] = 0xb2;
buf[1] = 0x00;
cksum = 0xc1;
Serial1.println("Evaporator Off");
}

****END OF CODE****

Let me know if you have trouble with it. I snipped portions of my code out that were specific to my application, so let me know if the above code doesn't work or if you have any questions.

[tom91]

I think my compressor is a Denso ES27C,

Can you please take pictures of your compressor and share them?

[abetanco]

These are the images from the eBay listing, since it is hard to take a photo of my compressor in my vehicle.

[abetanco]

It is a ES27C according to the listing, and it is from 2015 according to the listing.

[abetanco]

I think these are used in Nissan Leaf SV and SL editions.

[joeflickers]

Hi All,

I think my compressor is a Denso ES27C, but the tag is hard to read.

The code is as follows. Basically, it is a way to make the Arduino send a UART message that looks like a LIN message. Let me know if you have any questions!

****BEGINNING OF CODE****

#define EVAP_VOLTAGE_7_PIN 7

int brklen = 14; // 13 bits + 1 bit for break delimiter
uint8_t sync = 0x55;
uint8_t addr = 0xfb;
uint8_t buf[8] = {0xb3, 0x00, 0x00, 0x90, 0xFF, 0x00, 0x00, 0x00};
uint8_t cksum = 0xb7;
int baud = 19200;
uint16_t brk = (brklen*1000000/baud); // brk in microseconds

void setup() {
pinMode(18, OUTPUT);
pinMode(EVAP_VOLTAGE_7_PIN, INPUT_PULLUP);
Serial.flush();
Serial.begin(baud);
Serial.print(brk);
}

void loop() {

int evap_voltage_7_status = digitalRead(EVAP_VOLTAGE_7_PIN);

while (evap_voltage_7_status == HIGH) {
buf[0] = 0xb3;
buf[1] = 0x0c;
cksum = 0xb3;
} else {
buf[0] = 0xb2;
buf[1] = 0x00;
cksum = 0xc1;
}

pinMode(5, OUTPUT);
digitalWrite(5, HIGH);
digitalWrite(18, LOW);
delayMicroseconds(brk); // For 19,200 Baud, brk should be 677us for brklen of 14us
// or 729us for brklen of 13us.
digitalWrite(18, HIGH);
Serial1.begin(baud);
Serial1.write(sync);
Serial1.write(addr);
Serial1.write(buf[0]);
Serial1.write(buf[1]);
Serial1.write(buf[2]);
Serial1.write(buf[3]);
Serial1.write(buf[4]);
Serial1.write(buf[5]);
Serial1.write(buf[6]);
Serial1.write(buf[7]);
Serial1.write(cksum);
delay(200);
Serial1.end();
Serial.println(buf[1]);
Serial.println("Evaporator On");
}
buf[0] = 0xb2;
buf[1] = 0x00;
cksum = 0xc1;
Serial1.println("Evaporator Off");
}

****END OF CODE****

Let me know if you have trouble with it. I snipped portions of my code out that were specific to my application, so let me know if the above code doesn't work or if you have any questions.

Thanks for Sharing.. My compressor is different from this

[abetanco]

Thanks for Sharing.. My compressor is different from this

You should still be able to use the LIN code, but you will have to check if someone else on this forum or somewhere else has hacked your compressor. Once you have the correct message to send, you should be able to use my code.

Good luck, and let me know if you have more questions.

[joeflickers]

You should still be able to use the LIN code, but you will have to check if someone else on this forum or somewhere else has hacked your compressor. Once you have the correct message to send, you should be able to use my code.

Good luck, and let me know if you have more questions.

[joeflickers]

You should still be able to use the LIN code, but you will have to check if someone else on this forum or somewhere else has hacked your compressor. Once you have the correct message to send, you should be able to use my code.

Good luck, and let me know if you have more questions.

what is the minimum voltage required of the HV side of the compressor?

[abetanco]

what is the minimum voltage required of the HV side of the compressor?

Great work! I don't know, unfortunately, but I vaguely recall finding online that some similar compressors have an operating range of between 200 to 400 V DC. You could try checking out the service manuals, specifically the HA (Heater and Air Conditioning System) and HAC (Heater and Air Conditioning System Control) portions:
https://www.nicoclub.com/nissan-service-manuals

Otherwise, Mark Lines has some teardown reports that may be available free online.

[joeflickers]

.. A question.. Do you measure the system pressure for on-off control?

[abetanco]

Got it working.. A question.. Do you measure the system pressure for on-off control?

Wow! Congratulations! I remember the feeling when I first got it running.

Here is my experience. I turn the condenser fan on and off with a four-position (off, plus three evaporator fan speeds) switch. When the switch is on, the compressor and condenser fan also turn on, if wired properly.

There is a second switch, which I'll refer to as a potentiometer switch. The temperature in the cabin is controlled by this hi-low potentiometer switch. This potentiometer switch will turn on and off automatically, depending on its setting (how far along the knob is on the potentiometer) and on the evaporator temperature (not the cabin temperature). This is accomplished via a thermistor that is placed within the evaporator coils, which in turn is wired into the microchip within this switch. The thermistor is tied to this pre-programmed potentiometer switch that may be specific for the evaporator that I purchased from a supplier in Florida, though these switches may also be universal (I'm not sure). The company I purchased from has excellent customer service, affordable prices, and I would be happy to recommend them to you if you don't already have your own evaporator. There is also an excellent Youtube video online showing installation of an AC system in a classic car, and although the Youtuber didn't use an electric compressor, most of the information was relevant and invaluable to me.

As for the pressure, my understanding is that most compressors, if not all, have a pressure safety valve that will exhaust if the system is over pressure. I learned this from reading the two Heating and Cooling sections of the Nissan Leaf shop manual (available online for several years of the Leaf - let me know if you need the link). One section covers mostly electronics, the other section covers mostly the components, but there is a lot of overlap between the two sections. This manual tells you the safe operating pressures for the compressor. Also, apparently, Nissan offered some models with a CAN-controlled (I think) compressor, and other models with a LIN-controlled compressor. It appears you and I both have the LIN-controlled compressor. There is a lot more information I'm forgetting because it's been a while since I looked into this - once I got the AC running, I forgot about it since it has been working fine.

The ideal system pressure at which you should charge your system depends on ambient temperature and is also hose-dependent and system-dependent. By system, I mean the evaporator, dryer, condenser, hoses, etc.). If you purchase an after-market AC system (i.e., all the components minus the compressor, which you already have), it should come with a temperature-pressure chart for how you should charge your system. You will also need to make sure your compressor is clean, and that you use special compressor oil for electric compressors - using the wrong oil can create a short circuit and can be extremely dangerous, causing your compressor to explode, or worse. I had to completely take apart my compressor and clean it, after purchasing it, as it was full of old oil (this oil is hygroscopic and can foul within minutes of application, if not evacuated immediately). Also note that the compressor oil is toxic, so be careful and make sure you read all the warnings associated with it. I would also read through the Nissan Leaf shop manual sections, especially those referenced above.

Please let me know if you need any more help, or have any more questions. I knew almost nothing about AC systems before this installation, and within four months I had the AC system installed, so I'm certain you will be able to do it in short order as well.

Please also note that there is a lot of information I left out - I only give you the basics above, and I am by no means an expert, and thus my writeup is for informational purposes only. You undertake this project at your own risk. I am happy to share more with you, but since it has been a while since I did this, there is a lot I forgot. Please be safe when you do this work.

[joeflickers]

Wow! Congratulations! I remember the feeling when I first got it running.

Here is my experience. I turn the condenser fan on and off with a four-position (off, plus three evaporator fan speeds) switch. When the switch is on, the compressor and condenser fan also turn on, if wired properly.

There is a second switch, which I'll refer to as a potentiometer switch. The temperature in the cabin is controlled by this hi-low potentiometer switch. This potentiometer switch will turn on and off automatically, depending on its setting (how far along the knob is on the potentiometer) and on the evaporator temperature (not the cabin temperature). This is accomplished via a thermistor that is placed within the evaporator coils, which in turn is wired into the microchip within this switch. The thermistor is tied to this pre-programmed potentiometer switch that may be specific for the evaporator that I purchased from a supplier in Florida, though these switches may also be universal (I'm not sure). The company I purchased from has excellent customer service, affordable prices, and I would be happy to recommend them to you if you don't already have your own evaporator. There is also an excellent Youtube video online showing installation of an AC system in a classic car, and although the Youtuber didn't use an electric compressor, most of the information was relevant and invaluable to me.

As for the pressure, my understanding is that most compressors, if not all, have a pressure safety valve that will exhaust if the system is over pressure. I learned this from reading the two Heating and Cooling sections of the Nissan Leaf shop manual (available online for several years of the Leaf - let me know if you need the link). One section covers mostly electronics, the other section covers mostly the components, but there is a lot of overlap between the two sections. This manual tells you the safe operating pressures for the compressor. Also, apparently, Nissan offered some models with a CAN-controlled (I think) compressor, and other models with a LIN-controlled compressor. It appears you and I both have the LIN-controlled compressor. There is a lot more information I'm forgetting because it's been a while since I looked into this - once I got the AC running, I forgot about it since it has been working fine.

The ideal system pressure at which you should charge your system depends on ambient temperature and is also hose-dependent and system-dependent. By system, I mean the evaporator, dryer, condenser, hoses, etc.). If you purchase an after-market AC system (i.e., all the components minus the compressor, which you already have), it should come with a temperature-pressure chart for how you should charge your system. You will also need to make sure your compressor is clean, and that you use special compressor oil for electric compressors - using the wrong oil can create a short circuit and can be extremely dangerous, causing your compressor to explode, or worse. I had to completely take apart my compressor and clean it, after purchasing it, as it was full of old oil (this oil is hygroscopic and can foul within minutes of application, if not evacuated immediately). Also note that the compressor oil is toxic, so be careful and make sure you read all the warnings associated with it. I would also read through the Nissan Leaf shop manual sections, especially those referenced above.

Please let me know if you need any more help, or have any more questions. I knew almost nothing about AC systems before this installation, and within four months I had the AC system installed, so I'm certain you will be able to do it in short order as well.

Please also note that there is a lot of information I left out - I only give you the basics above, and I am by no means an expert, and thus my writeup is for informational purposes only. You undertake this project at your own risk. I am happy to share more with you, but since it has been a while since I did this, there is a lot I forgot. Please be safe when you do this work.

Excellent feedback, I can almost visualize your setup even without pictures or wiring diagram,i got to play around with my Toyota AURIS AC, setup in my car yesterday an i couldt believe how easy it is, it only has one highpressure sensor after the the conpressor ,the transducer is a simple 0-5v sensor,shorting the sensor to ground made the AC clutch di-engage and pulling it to 5v made it and disegege and the intercooler rad-fan kicked in full speed,good value were between 2.3-3.1v ,guess ill borrow a gen2 leaf from a freind and study it for proper pressure reconmended by nissan.

[joeflickers]

I Won't be continuing to use my earlier compressor from a GEN-1 but 92600-3NF0A as it just arrived, thee low voltage connector is well documented by Johu but i couldn't identify the polarity of the HV from this chat, I one can kindly share ,thanks

[johu]

As always a meter in diode mode will tell you. If it displays 0.7V or so you have found reversed polarity. Or just connect your lab supply, see in which direction it shorts out.

[joeflickers]

As always a meter in diode mode will tell you. If it displays 0.7V or so you have found reversed polarity. Or just connect your lab supply, see in which direction it shorts out.

aah,thanks,ive also found out that the compressor is exact part number but my low voltage pinout is on pins 2,4 and 5.guess the exact same test will help me get the polarity

[abetanco]

Nice work, please keep us updated.

Also, the Nissan Leaf shop manual shows the polarity, though it was difficult for me to find. Let me know if you need more help on this.