MIL on.

Code for P0409 (EGR Position sensor)

Code will not clear (KOEO)

(IE it immediatly resets without having to start or run the engine)

As far as I can tell, the supply, earth and signal wires seem to be giving credable voltages.

(Though Autodata is auto non-data on this model!)

The signal one varies if I apply vacume to the egr valve (and I can get a responce in the live data indicating that the valve operates when I do this "proving" the wiring between the Valve and the ECU and, i presume, ECU operation)

So what is the "stratagy" for setting this code and is there any other way of testing the EGR valve other than by replacing it.