The Exhaust Gas Recirculation (EGR) Valve Position (EVP) system uses an electronic EGR valve to control the flow of exhaust gases. The Engine Control Module (ECM) monitors the flow by means of an EVP sensor and regulates the electronic EGR valve accordingly. The valve is operated by a vacuum signal from the EGR Vacuum Regulator (EVR) solenoid which actuates the valve diaphragm.
As the supply vacuum overcomes the spring load, the diaphragm is actuated. This lifts the pintle off its seat and allows exhaust gases to flow. The amount of flow is proportional to the pintle position. The EVP sensor, mounted on the valve, sends an electronic signal representing pintle position to the ECM.
See Figure 1
- Disconnect the EVP sensor connector. With the ignition ON and the engine OFF , measure the voltage between VREF and SIG RTN terminals of EVP sensor harness connector. If the voltage is 4.0-6.0V, the power circuits to the sensor are okay.
- Reconnect the EVP sensor. With the ignition ON and the engine OFF , measure the voltage between EVP sensor terminals EVP and SIG RTN . If the voltage reading is 0.67V or less, the sensor is okay.
REMOVAL & INSTALLATION
- Disconnect the negative battery cable.
- Disconnect the wiring from the sensor.
- Remove the sensor mounting nuts and remove the sensor from the EGR valve.
- Attach the sensor to the EGR valve and tighten the mounting nuts.
- Connect the sensor electrical lead to the sensor.
- Connect the negative battery cable.