1. Check the Differential Pressure Feedback EGR (DPFE) Sensor voltage Key On Engine Off (KOEO). It should read roughly 1.0v.

2. If the voltage is not between 0.7v and 1.2v, verify the Brown/White (BR/WH) wire is 5v and that the Gray/Red (GY/RD) wire is a goo... Login to read more.