pwm Water Pump PWM

[mldc]

Hello,

Our team doing some upgrades this winter.
We have G4+ Thunder and PMU16 from Ecumaster.

I would like to run water pump with pwm settings.
I know that G4+ CAN can't transmit the pwm value, so I'm looking for alternative.

 

Water pump: CWA200

   

PWM settings:

 

 

 

Idea:

1. PMU16 feeds pump +12V when ignition is on.

2. I wire this to G4+ PWM signal Aux5 pin directly (high side) 

3. I wire this pin to G4+ signal ground. (Or should I wire it to chassis ground?)

4. GND is wired to chassis ground.

 

Working order:

I turn the ignition and power goes directly from pmu to water pump. When RPM gets over 200 I feed 3ms of pw to wake up the pump from ecu.

When car idles i send different signal to run the pump from ecu...

 

 

 

Can someone confirm that my theory should work?
Or I'm just wasting You time guys..

 

Huge thanks

[Adamw]

Yes, that will work fine.  The last time I set one up for someone I just had a cell in the PWM table that the engine always passed through during start up that resulted in the 3ms wake up.  

 

10 hours ago, mldc said:

3. I wire this pin to G4+ signal ground. (Or should I wire it to chassis ground?)

Either ground will work since it has a large threshold.

 

[mldc]

Huge thanks.

I own You a beer.

[Adamw]

Also FYI, from memory the DC works back to front - 0%DC gives 100% flow and vice versa.

[Scott33]

I don't think you want to use a high side output for this.  The aux outputs have built in pull up resistors, which AFAICT is enough to pull the pin high.  Then the low side switch is used to pull the pin low.

[mldc]

Hmm...
I also found the manual for of this pump.
There is a requirement that PWM must be 12V and 500mA.
You can check it too.

Maybe it will be useful for other members too.

manual_tinyCWA_manual_version.pdf

[Richard Hill]

That isn't the pump manual, The 500mA current specified is the maximum output of the TinyCWA controller, not the current consumption of the PWM input pin on the pump (which will be much lower).  You can control these pumps with either a high side aux, or if none available you could use a low side (I would add a 10k pull up resistor in the pump connector) 

Also, worth noting these pumps should be installed as low as possible and work best in a "reverse flow" configuration as they cannot suck air, and so will fail to pump if coolant levels are low and mounted in the top hose

HTH, 

Richard. 

[mldc]

Finally I understand the logic.

I will update You with result after wiring and first start.

 

It's really great to have this kind of community

[Davidv]

1 hour ago, Richard Hill said:

That isn't the pump manual, The 500mA current specified is the maximum output of the TinyCWA controller, not the current consumption of the PWM input pin on the pump (which will be much lower).  You can control these pumps with either a high side aux, or if none available you could use a low side (I would add a 10k pull up resistor in the pump connector) 

Also, worth noting these pumps should be installed as low as possible and work best in a "reverse flow" configuration as they cannot suck air, and so will fail to pump if coolant levels are low and mounted in the top hose

HTH, 

Richard. 

Hi Richard, 

Do you mean it's as simple as connect 12v pin, earth pin, and then 3rd wire to to an aux output set to high side direct to ECU?

Sounds  too good to be true! 

I was anticipating needing to make a pump controller or using SSR to trigger that 12v signal pin.

What do you do with the 4th pin on the pump, I was under impression this is essentially a pump speed tacho signal. So you can wire it to a DI. Is this correct? 

[Confused]

I'm running a CWA50 in my car as a chargecooler pump, so the flow varies based on engine RPM and IAT.

Here's my configuration:

 

[Adamw]

 

43 minutes ago, Davidv said:

Do you mean it's as simple as connect 12v pin, earth pin, and then 3rd wire to to an aux output set to high side direct to ECU?

Correct except there are 2 grounds.  And a GP PWM is lowside drive only.  But as I mentioned earlier these work fine connected directly to an aux out, they donot need a pull-up or anything.

You dont need the controller that mldc attached - this would be for someone that wants to control the pump without an ECU.

 

45 minutes ago, Davidv said:

What do you do with the 4th pin on the pump, I was under impression this is essentially a pump speed tacho signal. So you can wire it to a DI. Is this correct? 

What diagram are you looking at? On the pump there should be a 4 pin plug, +12V, a power gnd, a signal ground and a PWM signal.  There is no tach output.

 

2 hours ago, Richard Hill said:

or if none available you could use a low side (I would add a 10k pull up resistor in the pump connector) 

The G4+ PWM outputs cant do highside drive, only low side.  The Aux outputs already have a 1.5Kohm pull-up internally.  

[Richard Hill]

2 hours ago, Adamw said:

The G4+ PWM outputs cant do highside drive, only low side.  The Aux outputs already have a 1.5Kohm pull-up internally.  

Ah yes, Low side only, my mistake.  The reason I would add the 10k pull up in the connector is in case the ECU or Aux got disconnected accidentally, the pump would come on full speed.

[Davidv]

15 hours ago, Adamw said:

 

Correct except there are 2 grounds.  And a GP PWM is lowside drive only.  But as I mentioned earlier these work fine connected directly to an aux out, they donot need a pull-up or anything.

You dont need the controller that mldc attached - this would be for someone that wants to control the pump without an ECU.

Ahhh thanks, excited about this now!

Will put this back higher up the priority list haha. 

Does the signal ground wire need to go to the signal ground wire on ECU? Or both to same place? 

EDIT: Ahhhh no I get it now, feed it 12v constant then PWM on the earth pin back to ECU. 

[Adamw]

7 hours ago, Davidv said:

EDIT: Ahhhh no I get it now, feed it 12v constant then PWM on the earth pin back to ECU.

No, there are 4 terminals.  1 is constant 12V.  2 is the low current PWM signal from ecu. 3 & 4 are both constant ground (it differentiates signal and power ground but fine to connect them both to chassis).

[mldc]

Hello,

Did some testing, results are below.

 

Pump:
Any pump CWA50, CWA200 or CWA400 would work with these settings.
We use CWA200.

Wiring:
1 - wired 12V from the PMU16, 25A channel.
2 - wired Aux high state signal.
3 - wired to ecu signal gnd. 
4 - simple chassis GND.

 

ECU settings:

50% on cranking is for waking up the pump.
After that, You can use higher values then 50%.

If your idle is lower then 1000 RPM, adjust the PWM table axis and values to suit your application.

Results:

Our race car working temperature is 70 C.
 

In my case You can see that pump is working very slowly till 50 C. It's because I need to warm the coolant up as fast as I can.
If You change Aux PWM table values, You could get more linear interpolation.
Last chart shows how output current is ramping up as coolant temp warming up.

p.s: I have wired coolant pressure sensor. On full power pump is making 0.7 bar of water pressure in the system.

 

These settings are good starting point.


Thank You.