Hi All,
First saw this vehicle some time ago, sorry cannot remember the full fault code set as I'm at home now But P1814 EGR circuit was the one that seemed relevant. The garage I diagnosed it for fitted a new EGR valve and all was well for a couple of weeks. The problems came back again and the owner decided to take the vehicle to the main dealer who relieved him of £1200 and fitted a new engine loom.
Strangely enough the problems are back again. Symptoms are low power below about 2000rpm but above that it perks up ok although perhaps a little down on power. One DTC returns; P1814, descriptions vary according to machine but along the lines of "EGR circuit". The EGR solenoid is being driven and the feedback voltage varies accordingly.
I am having trouble finding an "in-depth" description of what this code means and the conditions for setting it. I did find some information that suggested this is equivalent to a P0400 "insufficient flow detected",but I am not sure how reliable that is.
My concern is "EGR circuit" could mean "electrical circuit" or it could mean "EGR gas flow circuit". The garage did check to see that the EGR pipe is clear as far as is possible and it looked ok. Does the EGR valve need an adaption performed after its replacement? Of course we could just get the customer to stick it back at the dealers door but I would like to get to the bottom of this myself if I can.
Shaun