Fault code P0404 egr cicuit range or perfomance keeps on apearing. I started to graph the vehicle, with my solus, to see what is happening. In a drive cycle, the continuos dtc conter registerd a fault, at the excact same time the egr position in mm droped to zero, where it is at idle. the egr position droped to 1.54 volts, which is also where it is at idle. and also the duty cycle egr vaccum regulator % droped to zero, which also where it is at idle. All this happend on the graphs at the same time. The performance of the van was fine. Every thing stayed on zero untill i turned the van off and restarted it then all the graphs were moving. I ran the same test, but pulled the plug off the egr valve, and everything happend the same, but the egr position in volts dropped right down to zero, once i plugged it back on, everything went back to normal, unlike when the fault isn't made by me pulling the plug off. when the problem occurrs its like the egr seems to be in standby at 1.54 volts untill engine turned of and restarted. I did the same test but pulled the vaccum hose off. all egr parameters dropped, volts to 1.54 but didn't come back once put back on. had to switch engine off and back on again.
I have checked the voltag by back probbing pin 1 and it is 5 volts and pin 2 ground is ok.
I am new to the diagnostics and would appritiate soom help