Somersetking

Could be blocked DPF, quite frankly these engines are crap for short town like driving, awful design! You might find this topic useful, your car may also go into limp mode when you get this message/light/warning - https://www.vauxhall.co.uk/help-centre/owners/cleaning-my-diesel-particulate-filter.html

Doesn’t need coding to car, I have a 2014 Insignia ecoflex CDTi SRi and mine just asked me to open and close all electric windows on first start up.