Lexus GS450H VCU Support Thread

[johnspark]

Congratulations sfk!

[xp677]

Well, after searching for 2 years, I now have a GS450h! And the good news is it's road legal and driving fine (though I think 1 or more cells in the battery pack could be a bit weak).

So this means I have the opportunity to collect CANBUS data and any other telemetry that would be useful to the development group as it'll be my daily commuter for the next month or so. If there is any specific data you are interested in please instruct me. I'll be going through past threads regarding canbus sniffing to get a suitable setup but chime in to recommend something please.

I plan on resurrecting my build thread at last. Exciting times.

Better data from the AC compressor would be great. I only had a chance to grab a small bit before I got an opportunity to sell the car on!

[steveknox]

Hi,
I've been trying to track down an issue with my setup and I'm getting nowhere. I'm having trouble with my inverter whereby the bus voltage is not being reported.

This issue started yesterday after rearranging my setup which involved plugging everything out and back in again.

Software: Version 7, very lightly modified. Previously working fine, so not a software issue.

Symptoms:
When I apply power (~ 25 v), through my precharge circuit (previously working), the main contactor will not open, and the dc_bus_voltage remains negative in the serial monitor output.
The voltage across the inverter inputs is around 1.3V

The voltage used to be reported (yesterday morning), but is no longer reported, so something has happened. I just don't know what!

When I 'force' close the main contactor by setting the precharge limit to -10 (yes, bad idea but i'm using low voltage), the inverter now works (The motor runs when pressing the accelerator) but the dc_bus_voltage remains negative. The voltage across the terminals is now ~ 25V

My guess is that there's some sort of loose or missing connection causing the voltage to not be reported, but I'm stumped as to which one it could be.

Attached is a screenshot of the mth_data, which is mostly reporting sensible data, and ad mentioned the motors spin fine once the main contactor is closed.

Does anyone have any idea as to which connector / connection I should be looking at, or have any other explanation of why this could be happening?

Thanks in advance,

Steve

[arturk]

Interesting problem. I do not why it happening but I have somewhat similar problem. When I power up my inverter it reports correct "DC Bus" voltage initially, until I spin motors up to around 3000 RPM then reported DC Bus voltage drops to around +100V (my battery pack is 360V) also "Another Temp 2" reports incorrect value at the same time. Otherwise I see no other side effects. It is annoying though. When I power cycle system I get correct values again until I reach "critical" RPM LOL.
Since it is installed in the car already and I have ISA shunt, I programmed my pre-charge circuit to use ISA as workaround.

[xp677]

You can always connect a 12V car battery or similar directly to the inverter inputs and see if it's reported correctly. The motors will spin at 12V as well (though not very fast).

Don't worry so much about the -2V, IIRC I added an offset to my code for my particular inverter, it may be different for different models. It might in your case be better to put a known voltage in and have a play until it lines up.

Also, if you set your mth_mask to all 1's, you can see the full data packet. The mask which I applied as shown in your screenshot was used to hide the "known" data to help me narrow down the purpose of the unidentified bytes.

Those two "another temp" were ones which I didn't find the source for. As far as I know, the unit has the following sensors:

MG1 IGBTs
MG2 IGBTs
Converter inductor
Water block

The latter two can be identified by unplugging them. The first two? For those I'm just going by the fact that the Toyota scan tool reports the MG1 and MG2 temperatures.

[steveknox]

Thanks for the replies guys.
By way of an update, I have resolved some of my issues:
1: The lack of voltage looks to have originally been caused by an intermittent short in my HV setup. I haven't identified the exact location of that short though which is somewhat concerning, and something I'll continue to look into. The behaviour came and went as I plugged and un-plugged the 3-phase cables. Curious.
For now at least here is a circuit being completed, which is allowing precharge to work.

2: The inverter is still reporting the HV bus voltage is still reporting as -2. Using a second inverter, I tested my setup and it reports the voltage correctly. So It's definitely an issue with this inverter, and not my setup. Taking @artuk's idea, I'm now using the ISA shunt to read the voltage. Precharge now works, and I can see accurate voltage being reported by the shunt.

So my setup is working as before (except now I have reverse courtesy of the zeroev gear selector!), but with a few nagging issues, namely the cause of the HV short, and the lack of HV being reported by the inverter. My guess is that the short killed whatever it is that reads the HV.

Let's call this case closed, but I guess it's something to be aware of that at least 2 of us now have the issue of the inverter not reporting the HV bus voltage, and having to rely on the shunt for this.

Thanks again!

[Jack Bauer]

I would always use the shunt for voltage measurement given the choice.

[xp677]

Not gonna lie, I have no idea how to use GitHub, so I'm just gonna post this here:

Speed from MG2 rpm:

Code: Select all

//for 255/40/R17 tyre
#define TYRE_WIDTH 255
#define TYRE_RATIO 40
#define WHEEL_SIZE 17 //inches
#define DIFF_RATIO 4.1 //x:1

#define TYRE_CIRCUMFERENCE (WHEEL_SIZE*25.4+TYRE_WIDTH*TYRE_RATIO/50)*3.14159265359/1000 //metres travelled in one wheel revolution
#define DIST_PER_MG2_REV TYRE_CIRCUMFERENCE/3.9/DIFF_RATIO/1000 //km car travels in 1x MG2 revolution
#define LOWGEAR_RATIO 2.05263157895 //how much lower the low gear is compared to high

      veh_speed_kph = mg2_speed * 60 * DIST_PER_MG2_REV;
      if (veh_speed_kph < 0)veh_speed kph *= -1; //for reverse
      if (prnd_gear == GEAR_LOW)veh_speed_kph /= LOWGEAR_RATIO; //low gear

Stick the defines at the top, and the 3 lines of code within the if(mth_good). Also define veh_speed_kph as a short int. For mph, just divide again by 1.60934.

Obviously change the four defines at the top to match your vehicle. The 3.9 is the ratio of the ravigneaux gearset in the "high" gear. For low, you divide it by that ratio. So if you're not using the low gear, remove that bottom line.


Inverter status diag readout thing:

define inv_state as a uint8_t or byte or whatever. Put this in the "if(mth_good)" braces:

Code: Select all

inv_state = mth_data[1];

Change the line

Code: Select all

else if(!htm_sent&&inv_status!=0){for(int i=0;i<80;i++)Serial1.write(htm_data_setup[i]);if(mth_data[1]!=0) inv_status--;}

to:

Code: Select all

else if(!htm_sent&&inv_status!=0){for(int i=0;i<80;i++)Serial1.write(htm_data_setup[i]);if(inv_state!=0) inv_status--;}

to neaten up the code. inv_state and inv_status was getting confusing so I renamed inv_status to inv_boot throughout the file, since it's only used on startup.

Then in your diag output function/whatever, stick in this bad boy:

Code: Select all

void diag_inverter()
{
  Serial.print("Inverter:\t"); Serial.print(digitalRead(pin_inverter_relay) ? "On" : "Off");
  Serial.print("\tStatus: ");
  if (inv_state == 0)Serial.print("Missing/Not ready");
  else if (inv_state & 0b00000001)Serial.print("Boot");
  else if (inv_state & 0b00001100)Serial.print("Ready");
  if (inv_state & 0b10000000)Serial.print(" - Current Sensor MG2-1 Missing");
  if (inv_state & 0b01000000)Serial.print(" - Current Sensor MG2-2 Missing");
  if (inv_state & 0b00100000)Serial.print(" - Current Sensor MG1-1 Missing");
  if (inv_state & 0b00010000)Serial.print(" - Current Sensor MG1-2 Missing");
  Serial.print("\tMTH Valid: ");
  if (mth_checksum > 0)
  {
    Serial.print(mth_good ? "Yes" : "No");
    Serial.print("\tChecksum: ");
    Serial.println(mth_checksum);
  }
  else Serial.print("--");
  
  if (inv_state & 0b00001100)
  {
    Serial.print("\tDC Bus: "); if (dc_bus_voltage >= 0)Serial.print(dc_bus_voltage); else Serial.print("----");
    Serial.print("v\tMG1: "); Serial.print(mg1_speed);
    Serial.print("rpm\tMG2: "); Serial.print(mg2_speed);
    Serial.print("rpm\tMG1 Tq: "); Serial.print(mg1_torque);
    Serial.print("\tMG2 Tq: "); Serial.print(mg2_torque);
    Serial.println();
  }
}

If you don't have a dedicated inverter relay, then don't use that line.

Other than that, it looks like the VCU code is up to date. I still haven't figured out which temperature sensor is which (I haven't been able to get anything hot enough to get a sensible reading yet!)

[steveknox]

Not gonna lie, I have no idea how to use GitHub, so I'm just gonna post this here:

This is great, thanks.

If you PM me your code, I can test it on my setup and then i'll do a pull request on github to save people the hassle of copy-pasting

[xp677]

There's no benefit to sending the code over. My code predates the VCU, Damien made chances to it to suit the features of his board, and I've branched off to make it specific for my project. My current code is not compatible with the VCU.

The only functional changes are already pasted above in the code tags. People can decide to use it if they wish.

[bobbyj_408]

Question, the VCU should work for an inverter was being used in a RHD gs450h, correct? Do I need any special considerations is I want to control a transmission from a LHD vehicle?

Thanks

[arturk]

I am using components from US version of Lexus GS450h in my Jaguar. The only difference is how to identify outputs for MG1 and MG2.

[bobbyj_408]

I am using components from US version of Lexus GS450h in my Jaguar. The only difference is how to identify outputs for MG1 and MG2.

Thanks, arthurk! Great. I have a lead on a LHD inverter, so I think I'll go for it. Does $600 sound like a reasonable price?

Also, I do need something to power the transmission for bench to testing. Would you happen to know the minimal power requirements to test the motor and the subsystems?

[arturk]

I think $600 is reasonable, from my experience they are hard to find much cheaper than that.
As far as power requirement for bench testing I think you can get motors spinning as low as 24V. I was testing with 48V-120V.

You can check out some of my early YouTube videos:


In this one I am actually using Camry Inverter, however I do not recommend it since I ran into some compatibility issues.

[bobbyj_408]

Oh wow! Sorry, I didn't put 2 and 2 together. I have seen your videos and am really excited about your Jaguar build! Please keep those videos coming.

Great! So I should be able to use two lead acids to get 24v.

Also, I just bought my 450h transmission today . I am really excited to embark on this journey, and hopefully it comes out well.

[bobbyj_408]

Oh, arturk, I am missing the resolver connectors. Any leads on where I could buy the connectors (or part numbers)?

[Jack Bauer]

https://openinverter.org/wiki/Lexus_GS4 ... Connectors

[bobbyj_408]

https://openinverter.org/wiki/Lexus_GS4 ... Connectors

Thank you!

[arturk]

Also, I just bought my 450h transmission today . I am really excited to embark on this journey, and hopefully it comes out well.

Bobby, I have a feeling it is going to be very exciting one
Please consider starting build thread and good luck!

[Gigas]

Oh wow! Sorry, I didn't put 2 and 2 together. I have seen your videos and am really excited about your Jaguar build! Please keep those videos coming.

Great! So I should be able to use two lead acids to get 24v.

Also, I just bought my 450h transmission today . I am really excited to embark on this journey, and hopefully it comes out well.

Looks nice - what year and how much if you don't mind me asking

[bobbyj_408]

Oh wow! Sorry, I didn't put 2 and 2 together. I have seen your videos and am really excited about your Jaguar build! Please keep those videos coming.

Great! So I should be able to use two lead acids to get 24v.

Also, I just bought my 450h transmission today . I am really excited to embark on this journey, and hopefully it comes out well.

Looks nice - what year and how much if you don't mind me asking

The transmission is from a 2007, and I got it for $500. I think I got a good deal . Hopefully I can also find a battery for a good deal.

[Gigas]

What would happen if you put a nissan leaf motor on the input spline instead of locking it out? basically just replacing the ICE engine with an electric one?

[mdrobnak]

What would happen if you put a nissan leaf motor on the input spline instead of locking it out? basically just replacing the ICE engine with an electric one?

There's another thread talking about that here: viewtopic.php?f=14&t=617 - please direct any questions to that thread.

[xp677]

A bit late to the discussion, but FYI you can spin the motors on 12V DC. They do stall at anything above around 100rpm, however for testing the communications, it's fine.

I ran mine from a 50A server power supply, I don't know how much current it uses. A car battery would be fine.

[Gigas]

Does this work on a 2013 or years in-between, as well? Seems everyone buy the 07 version of this transmission