Lexus GS450H VCU Support Thread

[Jack Bauer]

Due to the Covid-19 restrictions some areas are not accepting postal shipments. This is causing delays in my shipping timetable for Tesla and other boards to customers. Where possible alternative arrangements will be made with private couriers (DHL etc) to effect delivery. If no delivery service is available then the item will be retained until normal service resumes. If you are waiting for an item and feel this may have affected you then please contact ino@evbmw.com to check with me.

[Robbertjanzen]

To make it more clear, i have made a complete wiring diagram for the V2 board in visio.

As i am also missing the original wiring loom, unfortunately i can not check if all connections are correct.

I would really appreciate if everybody gives there remarks so i can modify and finalize the drawing.

Please also find the Visio file here:
https://www.dropbox.com/s/e42971nsftjav ... .vsdx?dl=0

[mdrobnak]

To make it more clear, i have made a complete wiring diagram for the V2 board in visio.

As i am also missing the original wiring loom, unfortunately i can not check if all connections are correct.

I would really appreciate if everybody gives there remarks so i can modify and finalize the drawing.

Please also find the Visio file here:
https://www.dropbox.com/s/e42971nsftjav ... .vsdx?dl=0

This is great! One thing that sticks out to me immediately is the oil pump relay - if you're going to drive it from the VCU, I'm 99% certain it's going to be ground switched by the device, not power switched. Pin 15 should represent ground on the relay coil, not +12V. (Unless the device has a half-bridge in which case I'll be quiet.)

Upon further looking this seems to be all relays.

The RHD / LHD split in the Toyota parts of the doc is confusing to me, I can't see any differences?

-Matt

[xp677]

The problem with ground switching relays is that if you have a freewheel diode mounted within the VCU, it will leak current through the relay coil and can potentially backfeed power into the VCU. This is because the 12V supply to the relay is essentially connected directly to the 12V supply to the VCU, when the ignition is on.

Wiring dependant. I prefer high side switching relays if using logic, low side switching if using physical switches (reduces chance of short circuits from wiring damage).

The LHD/RHD issue is due to a connector names between the LHD and RHD cars. Only relevant if you are re-using the Lexus looms. This could be simplified on the diagram, with a note added to the connector names, or maybe the connector names removed entirely.

My feedback on this drawing:

OPST should not be grounded, this is PWM feedback from the oil pump motor controller, it sends the motor speed. If this isn't to be used, just leave it unconnected.

This system should have a precharge resistor. I understand there aren't many outputs available, to solve this I would trigger the inverter relay and oil pump relay from the same output.

I don't like that there is no way to prevent motion when the car is not in R or D. There should be a connection from the D position of the shifter at least. This could go in where the ignition switch is currently. There is no need for an ignition switch input, just power the VCU from ignition power.

Maybe indicate the 4x serial data lines as twisted pair, or at least note it on the drawing. They should also be shielded at one end only (this is noted on the Toyota part of the drawing, but may not be immediately obvious). The DRN pins are available for shielding as shown in the diagram.

Just my two cents!

Otherwise all looks good. Nice presentation. I've designed a similar unit this year and have gone through all these considerations (and more!) myself.

This VCU could do with some more inputs and outputs in a later version. My equivalent unit has around 40 total, all of them are full.

[xp677]

Another potential way to prevent motion in R or N is to connect those positions to the HSDN pin of the transmission. +12V to this pin will shut down the power stage. No idea what would happen if you did this in motion, probably nothing good. I don't know how this input is interpreted by the inverter's controller, I never traced it. Might just be an input to the microcontroller, which can then make a sensible decision on the shutdown. Or might be more violent.

If you have no interest in the HSDN pin, you can leave it unconnected, I think you can ground it instead. I have it set on my controller to power down the inverter while the car is charging, as I charge through the HV converter and don't want to run the inverter power stage at that time.

[Jack Bauer]

The NCV8401 and 8402 low side switches used don't require freewheel diodes and are short protected.

[Robbertjanzen]

Great feedback all!

This is great! One thing that sticks out to me immediately is the oil pump relay - if you're going to drive it from the VCU, I'm 99% certain it's going to be ground switched by the device, not power switched. Pin 15 should represent ground on the relay coil, not +12V. (Unless the device has a half-bridge in which case I'll be quiet.)

Upon further looking this seems to be all relays.

The RHD / LHD split in the Toyota parts of the doc is confusing to me, I can't see any differences?

-Matt

I was not sure, but thanks, i have changed it in the new drawing.

The problem with ground switching relays is that if you have a freewheel diode mounted within the VCU, it will leak current through the relay coil and can potentially backfeed power into the VCU. This is because the 12V supply to the relay is essentially connected directly to the 12V supply to the VCU, when the ignition is on.

Wiring dependant. I prefer high side switching relays if using logic, low side switching if using physical switches (reduces chance of short circuits from wiring damage).

The LHD/RHD issue is due to a connector names between the LHD and RHD cars. Only relevant if you are re-using the Lexus looms. This could be simplified on the diagram, with a note added to the connector names, or maybe the connector names removed entirely.

My feedback on this drawing:

OPST should not be grounded, this is PWM feedback from the oil pump motor controller, it sends the motor speed. If this isn't to be used, just leave it unconnected.

This system should have a precharge resistor. I understand there aren't many outputs available, to solve this I would trigger the inverter relay and oil pump relay from the same output.

I don't like that there is no way to prevent motion when the car is not in R or D. There should be a connection from the D position of the shifter at least. This could go in where the ignition switch is currently. There is no need for an ignition switch input, just power the VCU from ignition power.

Maybe indicate the 4x serial data lines as twisted pair, or at least note it on the drawing. They should also be shielded at one end only (this is noted on the Toyota part of the drawing, but may not be immediately obvious). The DRN pins are available for shielding as shown in the diagram.

Just my two cents!

Otherwise all looks good. Nice presentation. I've designed a similar unit this year and have gone through all these considerations (and more!) myself.

This VCU could do with some more inputs and outputs in a later version. My equivalent unit has around 40 total, all of them are full.

Great feedback, Switching the power with ignition switch is a good point, Precharge contactor is added in the drawing.
Unfortunately visio does not really good support twisted pair drawing, but i have add a note.

I have used the R and D feedback on the two inputs

Another potential way to prevent motion in R or N is to connect those positions to the HSDN pin of the transmission. +12V to this pin will shut down the power stage. No idea what would happen if you did this in motion, probably nothing good. I don't know how this input is interpreted by the inverter's controller, I never traced it. Might just be an input to the microcontroller, which can then make a sensible decision on the shutdown. Or might be more violent.

If you have no interest in the HSDN pin, you can leave it unconnected, I think you can ground it instead. I have it set on my controller to power down the inverter while the car is charging, as I charge through the HV converter and don't want to run the inverter power stage at that time.

A good solution is to connect the Park pin to the HSDN pin of the inverter. This disables the power stage when in park.

Also find the latest version in visio:
https://www.dropbox.com/s/e42971nsftjav ... .vsdx?dl=0

[xp677]

Looks good! I'd add a fuse after the ignition switch or at least add a note. For most people, they will be re-using existing ignition power for engine ECU, etc, so a fuse would be available anyway.

10A should be fine? In real life, I'd put SL1 and SL2 on their own fuse, this is probably outside the scope of your diagram.

Also, just noticed your generator/MG1 temp sensor wires have cut under the Lexus diagram instead of going around.

You can simplify the 12v wiring a bit, the sqiggley bit just below the VCU can go away and be joined above the stop light switch.

[Kevin Sharpe]

I think you need a contactor for the negative side of the HV battery. Here's the BEXUS HVJB;

viewtopic.php?f=11&t=96&start=110#p7181

Edit: I think the ISA shunt is also required

[Alexstarex]

Inverters from 450 and 600 Lexus are identical?

[xp677]

No. They are very different.

https://www.osti.gov/servlets/purl/947393

The GS450h inverter is similar to the Camry unit.

[slow67]

Will the LS600h inverter respond to the same commands as the GS450h (plug and play)?

[Alexstarex]

No. They are very different.

https://www.osti.gov/servlets/purl/947393

The GS450h inverter is similar to the Camry unit.

THANK

[Robbertjanzen]

The black wire is for PWM control of the oil pump controller.

The brown wire is a feedback signal showing the oil pump rpm. PWM again. You can leave it unconnected.

See the attached diagrams, apologies if they aren't very clear, not sure what happened to them:





I should add, the only ground for this controller is the metal body of the controller itself, there is no ground wire. So the controller either needs to be bolted to something that's grounded, or you can add a ground wire to one of the bolt holes.

Also IIRC, only 3 of the bolt holes are threaded.

Great information. Your second diagram shows an external connection for the temp sensor connector. I missed it in the loom the first time. I just confirmed it is there. Thanks for everything again. Now time to find that connector.

Does anybody know the Pinout of the Oil Pump connector?

[arturk]

Check out schematic on wiki
https://openinverter.org/wiki/Lexus_GS450h_Inverter

[xp677]

The pinout is in the post you quoted!

Black is PWM in from your controller.
Brown is feedback from the oil pump. Do what you want with this or leave it disconnected.
The fat blue wire is 12V power. The metal case is the ground.

Edit: I updated the wiki to include this.

[Robbertjanzen]

The pinout is in the post you quoted!

Black is PWM in from your controller.
Brown is feedback from the oil pump. Do what you want with this or leave it disconnected.
The fat blue wire is 12V power. The metal case is the ground.

Edit: I updated the wiki to include this.

Yes i see the pin numbers, but i do not have the connector, so don't know which Pin is which wire...

[xp677]

Are the pins not numbered on the unit? That's annoying. See here:



You want the 3 pins on the centre row as shown. The fat red wire is actually the Toyota blue wire covered in red heatshrink.

[arturk]

Here is pin numbering on connector

[MattsAwesomeStuff]

Wow, the GS450H wiki page is way more fleshed out than when I last saw it:

https://openinverter.org/wiki/Lexus_GS450h_Inverter

Great stuff guys (oil pump pin numbering is already on there).

[Robbertjanzen]

Are the pins not numbered on the unit? That's annoying. See here:



You want the 3 pins on the centre row as shown. The fat red wire is actually the Toyota blue wire covered in red heatshrink.

Great! thanks!

[Jack Bauer]

Folks, I have a customer contact me stating he only speaks Spanish and is therefore unable to get assistance from the forum for a GS450H VCU. Do we have any Spanish speakers here who might help out?

[xp677]

Wow, the GS450H wiki page is way more fleshed out than when I last saw it:

https://openinverter.org/wiki/Lexus_GS450h_Inverter

Great stuff guys (oil pump pin numbering is already on there).

I've been adding everything that gets asked here. The diagram with the pin numbering got added just the other day.

What I've gathered so far, is that the damn oil pump almost needs its own page. There's more info about the pump than the inverter

[MattsAwesomeStuff]

Folks, I have a customer contact me stating he only speaks Spanish and is therefore unable to get assistance from the forum for a GS450H VCU.

Unable to help, espanol no es bueno.

He would likewise be unable to get assistance from you in person. He somehow managed to navigate and english webshop.

Google-translate is decently powerful for simple questions. Difficult to make sure you are using the most simple terms to describe a problem and a solution though. :/

[arber333]

Folks, I have a customer contact me stating he only speaks Spanish and is therefore unable to get assistance from the forum for a GS450H VCU. Do we have any Spanish speakers here who might help out?

DOH! Are you sure he is legit? Dont waste your time too much. Travel has become extinct, language and space barriers are up and world is suddenly getting bigger. Let him find someone to translate. I see even some Ukraininan and Belarus friends made their way .

I admire Chineese dinasties back in 3000BC, They had the vision and joined their world by THE comic book . Every person could think in its own language, as long as they WROTE the same glyphs.