October 30: LEMON manuals on a temporary server, it is slow and having issues, download the manuals you need! Later in November we will switch back to the fast server.

Possible Causes

EGR valve power supply circuit open.
EGR valve to ECM drive circuit pair (EGR valve pins No. 1 and 4, 6 and 3), open or high resistance.
EGR valve failure (stepper motor open circuit).