Circuit/System Testing
- With the ignition ON and the EGR valve disconnected, measure the voltage from the 5-volt reference circuit of the EGR valve to a good ground and observe that the DMM measures 4.98-5.02 volts.
- If the voltage is less than 4.98 volts, test for an open in the 5-volt reference circuit or for a faulty ECM.
- With the ignition ON and the EGR valve disconnected, connect a jumper wire between the 5-volt reference circuit of the EGR valve and the signal circuit of the EGR valve and observe with a scan tool that the EGR sensor parameter displays 4.98-5.02 volts.
- If the EGR Sensor parameter is less than 4.98 volts, test the signal circuit for an open or short to ground, high resistance, or for a faulty ECM.
- If the 5-volt reference and the signal circuits, test normal replace the EGR valve.