EGR Valve: Description and Operation

The linear EGR valve is designed to accurately supply EGR to an engine independent of intake manifold vacuum. The valve controls EGR flow from the exhaust to the intake manifold through an orifice with a PCM controlled pintle. During operation, the PCM controls pintle position by monitoring the pintle position feedback signal. The feedback signal can be monitored with a scan tool as ACTUAL EGR P0S. ACTUAL EGR P0S should always be near the commanded EGR position ( DESIRED EGR P0S).

The PCM uses information from the following sensors to control the pintle position:
^ Engine Coolant Temperature (ECT) sensor.
^ Throttle Position (TP) sensor.
^ Mass Air Flow (MAF).

The linear EGR valve is usually activated under the following conditions:
^ Warm engine operation
^ Above idle speed

LEGEND
(1) Cap-Sensor
(2) Sensor-EGR Pintle Position
(3) Pole Piece-Primary
(4) Bobbin and Coil Assembly
(5) Sleeve-Armature
(6) Valve-Pintle
(7) Armature and Base Assembly