Fault code 89 keeps coming on
2017 Vauxhall Corsa 1.3dti

This fault code keeps coming the van has been serviced regularly it's had a new battery new fuel filter and a new alternator but problem still happens. Last week it wouldn't start for three days all the lights came on when turning on the ignition and the radio worked but nothing else happened didn't even turn over on day four it started straight away with nothing being done to it very annoying.
Please help !!!