EGR Pressure Transducer System

EGR valve receives ported operating vacuum through an EGR pressure transducer. Refer to VACUUM DIAGRAMS article. Pressure transducer is operated by backpressure, controlling EGR valve opening. Under certain conditions PCM closes vacuum to pressure transducer (closing EGR valve), using a solenoid valve. Vacuum supply is shut off under following conditions:

• Low engine coolant temperature.
• Throttle valve in idle position.
• Engine under high load.
• Low intake manifold pressure.