Mariner 2WD L4-2.3L VIN Z (2005)
EGR Valve: Description and Operation
EXHAUST GAS RECIRCULATION (EGR) VALVE
Typical EGR Valve
Test Graph
The EGR valve in the DPFE system is a conventional, vacuum-actuated. The valve increases or decreases the flow of exhaust gas recirculation. As
vacuum applied to the EGR valve diaphragm overcomes the spring force, the valve begins to open. As the vacuum signal weakens, at 5.4 kPa (1.6
in-Hg) or less, the spring force closes the valve. The EGR valve is fully open at about 15 kPa (4.5 in-Hg).
Since EGR flow requirement varies greatly, providing repair specifications on flow rate is impractical. The on-board diagnostic (OBD) system monitors
the EGR valve function and triggers a diagnostic trouble code (DTC) if the test criteria is not met. The EGR valve flow rate is not measured directly as
part of the diagnostic procedures.
