EGR Valve Range / Performance Failure

EGR valve range / performance failure
The method employed to check EGR valve operation involves forcing the valve open and closed during an over-run fuel cut. A reading from the MAP sensor is checked before, during and after the valve operation. The difference in values between the open and closed states of the valve is checked against a map of engine rpm versus the difference value. If this calculated value is below or over the threshold, a failure is judged.