2008 R56 mileage 87,000 miles.

Fault code 28B4 : valvetronic servomotor, sluggish movement.

I replaced new valvetronic and do the reset in Sept, it is drivable but no power... ECU is good and check by ECU Professional. it become worse lately, it always stall at traffic light...

Doing another scan yesterday, 28B4 again, the workshop said valvetronic is broken again...

please help. Anything I need to check it before throw the money into new valvetronic again...

thank you for help.

 

Check this out, there are several solutions
https://www.pelicanparts.com/techart...nic_Faults.htm