openinverter forum

this comes at a perfect time for a little PWM Water Pump Shootout ! the PWPS using the Zombieverter VCU

introducing our contestants:

• Nissan Altima Hybrid coolant pump

• Toyota Camry Hybrid coolant pump

• Lexus GS450h Hybrid coolant pump

• Toyota Prius* Hybrid coolant pump

Note: the Toyota Prius 2nd gen did not use a three wire PWM inverter coolant pump, so this is the 3rd Gen Prius one above

first a little Mandatory Stare N Compare of the two wire non PWM controlled 2nd Gen (2004-09) Prius inverter pump part number: G9020-47031 to the four wire PWMed 3rd Gen (2010-15) one part number: G9040-48020


QUESTION: if no PWM was fine for TOYOTA in the 2nd Gen who's to say it may not be a headache free way to cool our EV Conversions? your thoughts?


TAKE AWAY: both pumps are made of plastic

Hey Greg, we get it that you are working within the TOYOTA/Lexus Eco System, so what's up with the Nissan Altima pump?

"The Altima Hybrid was Nissan's first hybrid car, first introduced in February 2007 and discontinued in 2011 for the 2011 model year. In the U.S. it was only available in 10 states that followed California's strict energy laws (California, Oregon, Connecticut, Maine, Maryland, Massachusetts, New Jersey, New York, Rhode Island, and Vermont), and was also available in Canada. Its hybrid-drive system was licensed from Toyota's hybrid technology."

~ Mr. Wiki

Thanks Greg for pulling this out, makes it easier to find for others.

I recommend you build a simple flow rig containing:
1. Pressure input gauge
2. Pressure output gauge
3. Output Flow meter
4. Valve to restrict the output to see the pressure flow impact.

Why is it a problem to control the pump speed? Seems like an advantage to have that feature. I have used multiple Tesla pwm controlled pumps and most recently control pump speed by coolant temperature, generally lower speed at cooler temperatures although for battery cooling at lower temperatures when battery heating is called for the speed is higher (using higher speed at low temps, then slows down and begins to speed up again once temperature reaches a certain threshold).

Dlud wrote: ↑Thu Jul 10, 2025 4:15 pm Why is it a problem to control the pump speed? Seems like an advantage to have that feature. I have used multiple Tesla pwm controlled pumps and most recently control pump speed by coolant temperature, generally lower speed at cooler temperatures although for battery cooling at lower temperatures when battery heating is called for the speed is higher (using higher speed at low temps, then slows down and begins to speed up again once temperature reaches a certain threshold).

Are you controlling it with the Zombie VCU ?

No, arduino using 2k temperature sensors.

Dlud wrote: ↑Thu Jul 10, 2025 4:20 pm No, arduino using 2k temperature sensors.

Nice, copy that, my goal is to see and show what the Zombie can do out of the box and how to do it in terms of PWMing.

https://openinverter.org/wiki/ZombieVerter_IO

CoolantPump - OUTPUT: activates during precharge, usually used for coolant pumps

Its on and off control of a coolant pump not PWM.

tom91 wrote: ↑Thu Jul 10, 2025 4:36 pm https://openinverter.org/wiki/ZombieVerter_IO

CoolantPump - OUTPUT: activates during precharge, usually used for coolant pumps

Its on and off control of a coolant pump not PWM.

see Tom we learned something already (yes I know this was documented way back in the legacy Lexus VCU days)

Gregski wrote: ↑Thu Jul 10, 2025 4:31 pm Nice, copy that, my goal is to see and show what the Zombie can do out of the box and how to do it in terms of PWMing.

Ah...didn't understand the context of your original post

The 2 wire pump may have been still pwm driven, just from the pump controller. Moving the pwm / motor controller in with the motor likely helps lower emi.

Hella sells a solid state relay that may be able to drive the 2 wire pump with zombie doing the pwm for it.

jrbe wrote: ↑Fri Jul 11, 2025 1:53 am able to drive the 2 wire pump with zombie doing the pwm for it.

The zombie DOES not provide a pwm for the pump unless:
1. you use the pwm output and set it up as described here:viewtopic.php?t=6403
2. you modify the code and create a new PWM output function

Already implemented here
https://github.com/Modellfan/Zombie-Sla ... ant_pump.h

modellfan wrote: ↑Sun Jul 13, 2025 8:49 pm Already implemented here
https://github.com/Modellfan/Zombie-Sla ... ant_pump.h

You can request things like this to be added to the main branch if tested. Be good to keep things aligned on this forum so people do not go off and run different branches making support more difficult.

muddling right along, lets do a mandatory stare and compare of all four pumps now


so although I am sure these can be re clocked ie the outlet tube orientation can be turned to where you desire it to point, you may be better off just starting with the correct pump orientation and not having to muck around with new gaskets etc. if you were to crack one open to twist it into submission

and I aint no metallurgist but clearly three of them appear to have some sort of an aluminum heat sync where as the Prius one is an odd man out being all out of plastic

alright let's get each pump's pinout out of the way

first up in alphabetical model name order, the Nissan Altima

Gregski wrote: ↑Mon Jul 14, 2025 4:02 am alright let's get each pump's pinout out of the way
.....
Nissan Altima Pinout.jpg

Sooo... what do you think is used? I would try 1kHz function first from 25% to 75% duty to see if it needs positive signal or is it pulled up inside the pump. In that case you would get 12V back on the middle wire unconnected and your transistor will be ok just PWMing in NPN mode.

This is how it is for GM
https://leafdriveblog.wordpress.com/201 ... -and-fans/

tom91 wrote: ↑Sun Jul 13, 2025 10:02 pm You can request things like this to be added to the main branch if tested. Be good to keep things aligned on this forum so people do not go off and run different branches making support more difficult.

My use case using Zombie as a Slave VCU is far beyond the normal use case. Espacially regarding the functionality of having a custom Low Voltage Distribution Unit using many of the Pins beeing used by different things in ZombieVCU. I don't see any chance to have my code as a branch. This is why I am pointing to my code, for whoever wants to have it in Zombie Code Base. With Codex, it should be integrated in a couple of minutes.

arber333 wrote: ↑Mon Jul 14, 2025 6:40 am Sooo... what do you think is used? I would try 1kHz function first from 25% to 75% duty to see if it needs positive signal or is it pulled up inside the pump. In that case you would get 12V back on the middle wire unconnected and your transistor will be ok just PWMing in NPN mode.

For Tesla Pump just connect the PWM line to a low side switch. PWMing between floating and low is enough. Have a look at my code. It implements already the valid signals as PWM range.

so I just came up with this wire harness for the OEM EV components PWM controlled water pumps and can't stop patting myself on the back, it can be used by the Lexus GS450h, the Toyota Camry, or the Nissan Altima coolant pumps

so that motivated me to revisit this thread, because I will use the Zombie to control an EV coolant pump, or die trying

alright boys, unless Tom rains on my parade (and he is more than welcome to do so, ha ha) we now have threeee pins to choose from, for at least the physical connection of the single PWM signal wire that our OEM EV coolant pumps require for control

correct me if I am wrong, but these pumps have a 4 pin socket, but only run 3 wires, one for dc negative, one for dc positive, and one for PWM control, if there was a 4th wire it could be PWM feedback signal, for example to report back to the Zombie how has the pump is spinning that sort of deal, but for just water cooling it is not needed we don't care for that type of precision

Gregski wrote: ↑Fri Feb 13, 2026 4:14 pm nless Tom rains on my parade (and he is more than welcome to do so, ha ha) we now have threeee pins to choose from, for at least the physical connection of the single PWM signal wire that our OEM EV coolant pumps require for control

It depends what else you are running on these PWM pins. They all share the same counter/frequency so not useable with CP spoofing or if you run your 1kHz GS450h oil pump control using those PWM pins.

What pwm frequency do these pump want? 100hz?

tom91 wrote: ↑Fri Feb 13, 2026 5:09 pm It depends what else you are running on these PWM pins. They all share the same counter/frequency so not useable with CP spoofing or if you run your 1kHz GS450h oil pump control using those PWM pins.

What pwm frequency do these pump want? 100hz?

thanks Tom, honestly I don't know but Google says: "it generally operates on a PWM signal with a frequency of 100Hz to 500Hz, with many aftermarket replacements and similar Toyota pumps using a nominal 100Hz frequency for control."

and all I know is that I will run the Lexus Oil Pump on what I call the standard Oil Pump PWM Pin # 30

sorry the forum is unbearably slow today, uploading pics is taking forever


meanwhile in this high tech lab cleverly disguised as an ordinary kitchen island, The Greg is still unable to control the Nissan Altima OEM EV inverter pump with the Zombie using PWM, the pump does work at full speed with only it's positive and negative leads connected


the pump is connected to the Zombie on Pin #7, I believe this is the correct connection, since when connected the pump goes from running at full speed to not at all


and here are my Zombie Parameter settings, is this not the correct choice for PWM1Func?


what am I doing wrong? what setting am I missing?

What are you looking to do?

PWM setup I linked before, it is not coolant pump. Coolant pump is an on off function.

tom91 wrote: ↑Fri Jul 11, 2025 7:33 am The zombie DOES not provide a pwm for the pump unless:
1. you use the pwm output and set it up as described here:viewtopic.php?t=6403
2. you modify the code and create a new PWM output function