Pathfinder 4WD V6-3.3L (VG33E) (1996)
EGR Valve: Diagnostic Trouble Code Tests and Associated Procedures
System Description
SYSTEM DESCRIPTION
This system cuts and controls vacuum applied to the EGR valve and EVAP canister to suit engine operating conditions.
EGR And Vacuum
This cut-and-control operation is accomplished through the ECM and the EGR valve & EVAP canister purge control solenoid valve. When the ECM
detects any of the following conditions, current flows through the solenoid valve. This causes the port vacuum to be discharged into the atmosphere.
The EGR valve and EVAP canister remain closed.
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Low engine coolant temperature
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Engine starting
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High-speed engine operation
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Engine idling
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Excessively high engine coolant temperature
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Mass air flow sensor malfunction
COMPONENT DESCRIPTION
EGR Valve
EGR Valve
The EGR valve controls the amount of exhaust gas routed to the intake manifold. Vacuum is applied to the EGR valve in response to throttle valve
opening. The vacuum controls the movement of a taper valve connected to the vacuum diaphragm in the EGR valve.