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
Re: PWM Water Pump Shootout
Posted: Thu Jul 10, 2025 2:35 pm
by Gregski
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
Re: PWM Water Pump Shootout
Posted: Thu Jul 10, 2025 2:36 pm
by Gregski
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
Re: PWM Water Pump Shootout
Posted: Thu Jul 10, 2025 2:39 pm
by tom91
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.
Re: PWM Water Pump Shootout
Posted: Thu Jul 10, 2025 4:15 pm
by Dlud
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).
Re: PWM Water Pump Shootout
Posted: Thu Jul 10, 2025 4:18 pm
by Gregski
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 ?
Re: PWM Water Pump Shootout
Posted: Thu Jul 10, 2025 4:20 pm
by Dlud
No, arduino using 2k temperature sensors.
Re: PWM Water Pump Shootout
Posted: Thu Jul 10, 2025 4:31 pm
by Gregski
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.
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)
kid-study.gif (4.71 MiB) Viewed 251 times
Re: PWM Water Pump Shootout
Posted: Thu Jul 10, 2025 6:51 pm
by Dlud
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
Re: PWM Water Pump Shootout
Posted: Fri Jul 11, 2025 1:53 am
by jrbe
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.
Re: PWM Water Pump Shootout
Posted: Fri Jul 11, 2025 7:33 am
by tom91
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