Communicating with the Lexus GS450h Inverter/Converter
Re: Communicating with the Lexus GS450h Inverter/Converter
Hi guys
Can i use Haltech ecu or unichip instead of damion's uc (microcontroler) is it possible ??
Can i use Haltech ecu or unichip instead of damion's uc (microcontroler) is it possible ??
- Kevin Sharpe
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Re: Communicating with the Lexus GS450h Inverter/Converter
Anything is 'possible'

To help you scope the challenge can I suggest you download Damien's controller code and try running it on your chosen hardware? This will tell you a lot about their development environment and support for third party software.
This is a personal post and I disclaim all responsibility for any loss or damage which any person may suffer from reliance on the information and material in this post or any opinion, conclusion or recommendation in the information and material.
Re: Communicating with the Lexus GS450h Inverter/Converter
hi guys i found a Forum that (mauswerkz) who converted a bmw with the gs450 gearbox and inverter he shared some of his work and what hed did
it might help us improve damions uc controler
https://forum.e46fanatics.com/showthrea ... 667&page=4
https://www.diyelectriccar.com/forums/s ... 42946.html
i know its too late for finding this guys work after damion finished the super youth but i think it will be usefull in some point
it might help us improve damions uc controler
https://forum.e46fanatics.com/showthrea ... 667&page=4
https://www.diyelectriccar.com/forums/s ... 42946.html
i know its too late for finding this guys work after damion finished the super youth but i think it will be usefull in some point
- Kevin Sharpe
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Re: Communicating with the Lexus GS450h Inverter/Converter
Many of the people on this forum are from DIY Electric Car and will be aware of the historical work on the Toyota/Lexus drive trains. Unfortunately, none of the detailed information was ever shared which is what forced Damien, Tom, and others to reinvent the wheel (same story with the Tesla drive units). It's critical we all learn from past mistakes and share knowledge as open source going forward

This is a personal post and I disclaim all responsibility for any loss or damage which any person may suffer from reliance on the information and material in this post or any opinion, conclusion or recommendation in the information and material.
- arturk
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Re: Communicating with the Lexus GS450h Inverter/Converter
Amoor, Lexus/Toyouta inverters communicate in synchronous way using 4 differential signal lines. None of the controllers you mentioned has this kind of interface built. And then there is still software to be developed. It is really not good application for these controllers because in a way these controllers are almost equivalent of the inverter in ICE world. They manage running of combustion engine and inverter manages running on electric motors. Both have to be controlled by something. In out case you need controller just like one Damien designed.
Another option is to get stock Arduino DUE and just build interfaces around it such as serial communication transceivers and drivers. This would be pretty easy to do since required components are easy to solder. Still, it only makes sense if you are not able to use Damien's board.
1998 Jaguar XJR, GS450h drivetrain, 48kWh/96s BMW battery
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Re: Communicating with the Lexus GS450h Inverter/Converter
This project is what alerted me to the potential of these units, and let me know that it was indeed possible. In the end, I was unable to contact him to discuss any of his code, and instead I purchased a GS450h, and received advice from others who have completed similar projects. As was mentioned, it required reinventing the wheel!Amoor wrote: ↑Mon Dec 09, 2019 1:52 pm hi guys i found a Forum that (mauswerkz) who converted a bmw with the gs450 gearbox and inverter he shared some of his work and what hed did
it might help us improve damions uc controler
https://forum.e46fanatics.com/showthrea ... 667&page=4
https://www.diyelectriccar.com/forums/s ... 42946.html
i know its too late for finding this guys work after damion finished the super youth but i think it will be usefull in some point
No idea, but I built an earlier version of the controller that Damien has released, using a $15 PCB from a fab company in China, with around £30 of components, so, what's the point?
If anyone is interested, I can cut down the schematics for a my early controller, which accepts a complete Due board, and post that, this would reduce the soldering required to just the CAN transceivers and associated components.
Re: Communicating with the Lexus GS450h Inverter/Converter
I would love it if you would do that. I have having multiple options.
Re: Communicating with the Lexus GS450h Inverter/Converter
[/quote][/code]No idea, but I built an earlier version of the controller that Damien has released, using a $15 PCB from a fab company in China, with around £30 of components, so, what's the point?
If anyone is interested, I can cut down the schematics for a my early controller, which accepts a complete Due board, and post that, this would reduce the soldering required to just the CAN transceivers and associated components.
[/quote]
yes please
If anyone is interested, I can cut down the schematics for a my early controller, which accepts a complete Due board, and post that, this would reduce the soldering required to just the CAN transceivers and associated components.
[/quote]
yes please
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Re: Communicating with the Lexus GS450h Inverter/Converter
OK, see attached, this schematic should work fine. I have laid out the board similar to my original controller, it's up to you to finish the layout and route it - that's too much work for me to do right now.
It should autoroute if you play with the component locations a bit.
Created in Eagle 7.6. Rename the files to .sch and .brd
It should autoroute if you play with the component locations a bit.
Created in Eagle 7.6. Rename the files to .sch and .brd
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- mini_master.brd.txt
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- mini_master.sch.txt
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Re: Communicating with the Lexus GS450h Inverter/Converter
I've already changed a few components since my last post. The FDT457N is much larger than needed for many of the tasks, a smaller FET such as the PMV20ENR would be more suitable for the relay driving, and you can likely use something even smaller for the PWM taks. I used the larger FETs all round due to laziness.
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Re: Communicating with the Lexus GS450h Inverter/Converter
What kind of update are you looking for? As far as I'm aware, the work to establish communication with the GS inverter is complete.
Re: Communicating with the Lexus GS450h Inverter/Converter
I just purchased a pump controller. Is the pump control built in to the VCU? Or do I need to build something separately to control it?Jack Bauer wrote: ↑Thu Nov 07, 2019 6:09 pm Got the pump controller fitted and now running from the main controller via pwm at 1khz. Pump speed is straight proportional to pwm duty. Needs a pullup resistor of 1k to 12v. Seems to take around 25amps at 50% speed. Last piece of the puzzle is to lock the input shaft then can start testing in the car.
Re: Communicating with the Lexus GS450h Inverter/Converter
The vcu generates a PWM signal, which goes to the pump controller ecu and will see the pump speed. For the moment most people are running the pump at half speed, but this can be optimized in the future.
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Re: Communicating with the Lexus GS450h Inverter/Converter
Lets use the support thread for these questions to keep all the info together.
Oil pump speed requirements have not yet been investigated. I'm sure half speed is fine for testing.
Oil pump speed requirements have not yet been investigated. I'm sure half speed is fine for testing.
Re: Communicating with the Lexus GS450h Inverter/Converter
I was under the impression the support thread is only for the VCU questions. I have a few questions and really didn't know where to post since there are 3 threads for the GS450h components.
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Re: Communicating with the Lexus GS450h Inverter/Converter
No worries, feel free to ask wherever. Your question before was specifically regarding Damiens VCU connection to the oil pump controller, however.
This thread was intended to cover the serial communication protocol used in the GS450h inverter. The work to decode this has now been completed and published, I don't see a need for this thread any more.
This thread was intended to cover the serial communication protocol used in the GS450h inverter. The work to decode this has now been completed and published, I don't see a need for this thread any more.
- Kevin Sharpe
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Re: Communicating with the Lexus GS450h Inverter/Converter
Ok, i'll lock it... if anyone want's it open again send me a PM

This is a personal post and I disclaim all responsibility for any loss or damage which any person may suffer from reliance on the information and material in this post or any opinion, conclusion or recommendation in the information and material.
Re: Communicating with the Lexus GS450h Inverter/Converter
I saw a post early on in this thread where Damien said all diodes in this build are backwards and need to be flipped. I have the v2 controller, and have looked at the v2 pcb pdf. It is not clear to me which side the anode and cathode oh diode “D3” should face. Is the anode supposed to be closest to “C40”?
All I need is a tree and a come along
- Teknomadix
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Re: Communicating with the Lexus GS450h Inverter/Converter
Remember this common mnemonic: ACID, that stands for "anode current into device"
Now. Look at the PCB. You will see that the anode of 'D3' faces the cathode of the adjacent elec. capacitor 'C40' the Cathode of 'D3' is tied to a via, that follows a trace on the underside of the board and onward to join with Connector B, Pin 1 "12V Supply In". D3 is there to act as an electrical 'check-valve' to allow power to flow in from the 12V supply line, but not backwards out of it.
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Re: Communicating with the Lexus GS450h Inverter/Converter
Please use the thread here for discussions on the VCU:
viewtopic.php?f=14&t=396
This thread is for discussion of the Toyota/Lexus HVECU <-> MGECU serial protocol.
viewtopic.php?f=14&t=396
This thread is for discussion of the Toyota/Lexus HVECU <-> MGECU serial protocol.
- mdrobnak
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Re: Communicating with the Lexus GS450h Inverter/Converter
I see you said this is 'complete' but did we ever figure out how to get regenerative braking set up? I saw a reference in another thread to bytes in the packet (htm array position 63/64) which don't seem to be modified by the code posted on Github. I'm more curious as to where they located that info?
So, one thing, looks like we have an off-by-one issue. Array positions 63/64 are going to be 64/65 in the spreadsheet, as that starts at *1*, and arrays always start at 0.
So, from this:
Is it a simple off-by-one issue?
What is the correct scaling to use?
Thanks,
-matt
So, one thing, looks like we have an off-by-one issue. Array positions 63/64 are going to be 64/65 in the spreadsheet, as that starts at *1*, and arrays always start at 0.
So, from this:
Is it a simple off-by-one issue?
What is the correct scaling to use?
Thanks,
-matt
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Re: Communicating with the Lexus GS450h Inverter/Converter
From the VCU thread, arturk mentioned the same thing, I believe he is having a look through some of the old logs pulled from a GS to see what they do with that.
I grabbed a random frame from a log of an idling GS, here it is:
In this example, the value is 2F0B, or 12043. Probably not much help as to get a good regen value you'd need to pull it from a GS that is regenning.
Just a thought that this data may need to be sent during init, so you'd want to add the data to the init/setup array as well (or have it update the array when sending init).
I grabbed a random frame from a log of an idling GS, here it is:
In this example, the value is 2F0B, or 12043. Probably not much help as to get a good regen value you'd need to pull it from a GS that is regenning.
Just a thought that this data may need to be sent during init, so you'd want to add the data to the init/setup array as well (or have it update the array when sending init).
- catphish
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Re: Communicating with the Lexus GS450h Inverter/Converter
I have a question about this. I'd have expected these pairs of control lines to be RS422 or similar, rather than CAN levels.
Do we have any scope traces of these raw signals, or any other confirmation of what levels these proprietary transceivers use?
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Re: Communicating with the Lexus GS450h Inverter/Converter
I was suspicious about exactly the same thing and posted a question about it here https://openinverter.org/forum/vie ... #p52724 . If a scope capture is available it would be pretty easy to tell the difference.. I did have a look at the same chips on a Prius board but couldn't get it to send data but based on a comparison of pinouts I concluded that the chip did appear to use the standard CAN pinout rather than the standard RS485 pinout so CAN bus seemed more likely. Would still be interested in seeing captured waveforms though.