Sorry, I was rushing when I posted this,
I meant to say set the 2 wire PWM setting to : B&G ON-OFF the buzzing from the relay bog goes away.
When it is set to PWM at the top or first setting... there is a loud Buzzing from the relay box.
I will check the other settings and get some more useful information tonight.
It is MS1. I purchased it from Nige a number of years ago.... 4 or more id say.
If the ECU is not capible of taking the PWM valve, so be it. not an issue. it runs fine without it....