Fault code DF312 "SPEED SIGNAL"
Car came in with partical filter warning & had blown off the front pressure sensor pipe.
Removed & cleaned the filter, done a forced regeneration & all cleared.
500 miles later same fault, so fitted a new partical filter,regen & all good.
500 miles later same again
Each visit had code DF312 which would not clear unless a forced regeneration was carried out,
soot content was 67 & 0 after regen.
History had 8 regen attempts.
Cant find any info on the fault code, seems to me the car needs some speed info to complete the regen prosess, & that unit is not working.
Where is it, what does it look like.
I have now got 3 cars all the same.