openinverter forum

Hi all,

I have just recently began a project using the Gs450h inverter and drivetrain to hopefully complete a full conversion of a 1997 Jag Xk8 as my 6 month work placement in University. I am at the stage where I have now just received the inverter, transmission, oil pump & controller and entire loom. Luckily we have the Gs450h so we are able to take looms and components were needed.

I have done quite a lot of research over various videos, threads and wiki pages in the last few weeks. I am using the Zombieverter VCU board and have watched countless videos from Damien to get comfortable. I am about ready to start my first spin tests but the one thing I was hoping to confirm is do I need the ISA Shunt for the first stages of bench testing? This is the only component I do not have currently and upon reading through the wiki support page I did notice a line: "Without a proper UDC measurement, the ZombieVerter will fail precharge and never go into run mode."

If I am using two supplies, one +12V and the other around 30~40V for just initial stages to ensure operation and wiring will I still need the Shunt or an equivalent way or providing a UDC value to the VCU.

Would be great to hear from someone with a bit more experience on the topic.

RianGill wrote: ↑Wed Mar 26, 2025 11:29 am ISA Shunt for the first stages of bench testing?

Yes.

And does that just have to be measured across the high voltage + and -. For these initial test at around 30V will a fully functioning precharging setup be needed? I know on the older Gs450h VCU that wasn't the case but with the Zombieverter is that needed or only a UDC value for it to read.

The Shunt needs to measure it.

You can always manually precharge with a resistor. Zombie wont know it has not done the precharge itself, it will skip through it if the voltages UDC and UDC2 are matching.

I do not know at what voltage the Lexus inverter will work.

I have gotten the ISA Shunt since then, (although I didn't realize it doesn't come with connecters - lesson learned), and will be ready to go very soon.
One question - one the Lexus Gs450h transmission the gear selector solenoid, do you also wire this to your +12V switch which indicates to the zombie the direction, pins 54 and 53.

Currently I just have the switches sending 12V to those pins without the transmission side of the wires being connected, seems like a simple answer of yes of course because how would the transmission know, but still wanted to check

RianGill wrote: ↑Wed Apr 09, 2025 2:17 pm one the Lexus Gs450h transmission the gear selector solenoid

What are you on about? There is a gear selector switch on the GS40h. https://openinverter.org/wiki/Lexus_GS450h_Drivetrain

Check the wiki on how to wire the selector and gear solenoids and pressure switches used in the GS450h

It's just a selector switch on the transmission - if you want to use the shifter mechanism as originally designed, then wire it in. If going with something different, such as F-N-R switch on dash etc, then no need. You may still want a mechanical linkage to engage and disengage the parking pawl.

As Tom mentions, the gear solenoids and pressure switches are different, and used for things like high/low. Wire those as per wiki

I understand that is a normal selector, I am looking right at it lol. Just questioning the integration of the solenoid wiring with the zombie wiring, not how a gear selector works.

Unsure yet of how I would like to integrate into the dash and do unique parts with it but i'm sure it will come up soon.

RianGill wrote: ↑Wed Apr 09, 2025 3:09 pm Just questioning the integration of the solenoid wiring with the zombie wiring

Just to be clear you are on about the Gear Shifter, unlock solenoid?

this is something I have been working on implementing. There is this functionality in the testing branch now.

I think I actually just confused myself upon further reading. So yes I am interested in doing some more unique setups going forward but I just now want a basic operational unit.
Instead of all the complicated stuff I was mentioning with the switches I have now realised and am guessing that you just wire "D" to pin 54 and "R" to pin 53, when one of those gears in selected that will send the signal to that pin indicating to the VCU which direction it is going, instead of not having to deal with the nonsense of multiple selectors that I was suggesting.
Does the Shifter plug send a 12V signal? or will a pull up/down resistor be needed in order to correct the signal to the VCU?

Follow the wiring info on the wiki. https://openinverter.org/wiki/Lexus_GS450h_Drivetrain

12V into the transmission mounted shifter position sensor/switch

tom91 wrote: ↑Thu Mar 27, 2025 5:14 pm The Shunt needs to measure it.

You can always manually precharge with a resistor. Zombie wont know it has not done the precharge itself, it will skip through it if the voltages UDC and UDC2 are matching.

I do not know at what voltage the Lexus inverter will work.

Hi again,

Back now finally with ISA connectors, have it wired up (very basic first test) using just a headlight bulb to test communication with shunt and zombieverter. When bench testing (using power supplies), what must be done in order to get by the pre charge fail error with the zombie verter.
Also a few basic questions, I just want to make sure my basic understanding is correct, when using the GS450h system with a zombieverter VCU, am I correct in not having to open the buck/booster converter? currently I have completed all the wiring from the transmission, shunt, vcu, etc, but I have not opened anything with the inverter except for access to the two terminal posts on the side which is where I am putting my HV source.

Currently the VCU has communication, getting information from the shunt (however it is all random unreadable values, i believe it might be due to the wiring on the shunt, only using crocodile clips for first com test), throttle fully working and direction working. I want to get a reasonably low voltage test working before I up the supply. Currently when applying power to the inverter I still hear no inverter wine, I think I might not be applying the min voltage/current needed, I have tried 30V @ 6amp or 61V @ 4amp, and still no noise from the inverter.

So in summary:
1. How does pre charge fully work for bench testing?
2. When using zombie verter is it really just plug and play or is there additional steps I have been naive too?
3. Min voltage/current needed for inverter testing?

Thank you.

Have a look here it will work the same as here.

viewtopic.php?t=6370

Yup was the exact same problem with the startup when initializing the shunt.
That is all working now, just need a precharge resistor now and then test run the full setup, not sure if the 30V @5amp will be enough to get the inverter operational.

Thank you again

RianGill wrote: ↑Thu May 22, 2025 8:27 am30V @5am

No.

Get atleast 60V worth of battery. The user in the linked topic had issues with his 60V 5A supply not providing peak power requirements and sagging too hard.

I know have 61V of supply but I still have some issues.

So I have my prechrage resistor and and manually switching after precharge is complete. I am still yet to hear any inverter wine, my communication from it seems to be inconsistent, some times when I am testing, on the web interface I get errors and precharge failed, other times the op mode goes straight into run but the inverter seems like it has no communication.

My shunt is picking up on the right values and I have the UDCsw set to around 50V, not sure if there is a common issue people have ran into here or a way to check an inital powering of the inverter.

Any help is appreciated. Thanks

Do the following if you need help:
Post params
Post plots of the values
Post wiring information
Post pictures of setup

Perfect, I will get on that, I think I have a few simple things to look over before I go wasting anyone's time.

Looking through the forums and things like grounding the inverter casing I glossed over: Ground the case to the same controller ground or from the other "HV" PSU?

Will tidy the rest and post the needed parts.
Thanks

Ground is vehicle chassis ground/12V ground. HV ALWAYS floats both the return/negative and the positive

So I have grounded the inverter now properly, just giving an outline of the setup, not ideal at the moment, using two supplies to get up to 60V, but now still nothing from the inverter, and not even a current draw from the supplies. Is there a common issue where this can happen? I have attached my parameters as well for the current stage. My communication with the inverter seems to be inconsist, sometimes I will see errors for precharge and a status and other times like in the photo I have attached it is like there is no coms.

Please feel free to tear apart the photos, the lab I am working in at the moment for a professor has like no supplies and I am being told to "make use of what I have", so if there is a few connectors that are a no go please shout at me.

Thank you

... No thats not the inverter but the Zombie Verter status.

Show you spot values.

Show all your low voltage wiring too please. Did you fully wire it as explained here: https://openinverter.org/wiki/GS450H_with_zombieverter

The wiring for UDC1 into the shunt needs to be inverter side not supply side, but for bench testing it should be fine.

For bench testing set UDCsw to 0, you are manual pre charging.

You need to get the zombieverter reliably into run mode first, this has nothing to do with the inverter comms.

Then you need to establish if you are getting information from the GS450h Inverter, spot values like INVudc and tmphs are good indicators if the comms works.

Ok so I have placed some photos of the low voltage wiring, bit of a mess at the moment but yes I did follow the wiring with the Gs450h and zombie from the start, there is a few parts of it i'm aware are missing, for example - B and B+ from inverter are not connected via a relay at the moment, they are just connected to a constant +12V that also goes into the zombie perm +12V.

I am working with the entire lexus Gs450h loom as we have the entire car, so all cables are stock for the most part including the resolvers. I have connected the inverter casing to the LV ground now as well. I moved the UDC1 to the inverter side (don't know how I expected to measure the voltage rising from where I had it lol).

I have uploaded the spot values as well, this zombie I have is on firmware 2.20.A (picked it up from where someone had it, they just bought it a while ago never started wiring it).

Thank you all

RianGill wrote: ↑Fri Jun 06, 2025 2:06 pm for example - B and B+ from inverter are not connected via a relay at the moment, they are just connected to a constant +12V that also goes into the zombie perm +12V.

That wont work, you need the relay controlled by the zombie. The zombie pulls the relay coil to ground to turn it on at the right time.

Spot values are not useful if you do not have it in run mode or errored out also all your outputs are off.

Try changing the UDCsw to 0 and starting the zombie to see if it now enters run mode without errors.

Ok, I will get a relay sorted and try from there, that was my next guess for getting it working.

Don't know how I forgot to flick it on when I sent those spot values, Once I have the relay in I will re send it all. Would the relay be enough itself to not get it into proper operating mode?