Testing stepper motor with 12 V battery

[feithv8s]

I have taken the stepper motor of my V8S out for testing as setting idle is quite bad.
The stepper motor has two coils, I think to give more or less valve opening.
Two coils with each two connections: resistance acc. the bible is OK.

My question: is it possible to see the stepper motor actually working when taken out and just connecting 2 pins to a 12V battery?
I tried, heard a very very soft click, but did not see the valve moving.

What signals are coming from the ECU?

Regards,
André Feith
V8S

[steve-v8s]

No, you can’t drive a stepping motor directly from a DC supply. There are two coils that have to be driven with the correct phase signals to make it “step”. Best way is to connect it to the car and turn the ignition on. You should see it reset to the default position. Other than that you need a stepping motor driver circuit.

[shpub]

Not only that stepper motors generally don't like batteries stuffed up them as it can lead the coils to go bang. If the stepper is at fualt the ECU usually reports a fault code. Failing that, it may be you need to set up the base idle. Covered in the bible.