I connected my Pierburg CWA200 waterpump to the MS but cant get it to work with PWM output


According to the datasheet it needs 150hz and 50% duty cycle to wake up. But all doesnt work. If i apply 12v to the pwm it will spin at full speed. Just as the datasheet says. But with the PWM nothing.


Or the waterpump pwm circuit is broken or something or my battery is not strong enough. Tommorow my new battery arrives. But this is just a guess those 2 problems

 

not much to add because I don't know the specifics of it...

does the pump have dedicated heavy duty wires for the pump itself and then another feed to the controller... or does this setup use a steady state solenoid with pwm of the full power?

 

The pump has 4 wires. 12v/PWM input/test signal/Ground.

So it needs 12v and ground, and then a PWM signal from a controller

 

is it possible that you can test your pwm output from the ecu?

thinking out loud, do these pumps need a controller in addition to the pwm? it could be that you need to hot-start the pump motor to get it running in advance of the PWM input to slow it down, which would correlate with what your seeing. im not sure how to test that, because you don't want to backfeed into the pwm output. but you should be able to hook up a momentary switch to 12v as well as your pwm to the pump and manually switch the pump on with the switch to see if the pwm controls it after that.

 

Possibly silly question, but are you certain that you've configured (in hardware) the PWM output you're using from the MS to output +12, rather than Ground, which is the default?

 

8.1. Input frequency
The frequency of the PWM signal can be in the following range:
Range: 50 to 1000 Hz
Note: To make sure that the pump awakes under PWM controlling, an uninterrupted high pulse of at least
3ms is necessary at the PWM input. For example: this is automatically achieved at a PWM frequency of 150
Hz and a duty cycle of 50% or above.

EDIT: appropriate .pdf's attached. Fantastic little pumps.

 

IIRC, 12V outputs (except tach) are all open drain, which require pull ups. The high side drivers are 5V (spark outputs)

 

All thx for answering, i got no luck yet getting the waterpump to work so i bought a dedicated waterpump controller from tecomotive. Its plug and pluy for the pierburg waterpump

It is fully independent, so it calculates everything by itself. including a delayed shutdown

 

To reiterate: have you modified the MS such that it is outputting a +12 signal from the PWM output, rather than a switched ground signal?

If not, this is almost certainly the problem.

 

Ah sorry forget to type a response. I dont really know if it is ground switched or +12. Someone else build my MS3x.

I could try to figure it out but it would take me long time to figure it out.

plus side of the tecomotive controller. The unit it much more advanced than the simple PWM output. And i dont have to setup everything because there are presets.

downside is the cost.. :(

 

If you don't know, then it's a switched ground, and that's why it isn't working.

You need to add a pullup, and configure the software accordingly. This is a 20 cent modification.