Evaporative Emission (Evap) Control System; Ev Ap Canister; Evap Canister Purge Valve; Fuel Tank Pressure (Ftp) Sensor - Honda Civic 2002-2003 Service Manual

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Evaporative Emission (EVAP) Control
System
Refer to the System Diagram to see the functional
layout of the system.
EV AP Canister
The EVAP canister temporarily stores fuel vapor from
the fuel tank until it can be purged back into the engine
and burned.
EVAP Canister Purge Valve
When the engine coolanttemperature is below 149°F
(65°C), the ECM turns off the EVAP canister purge valve
which cuts vacuum to the EVAP canister.
Fuel Tank Pressure (FTP) Sensor
The FTP sensor converts fuel tank absolute pressure
into an electrical input to the ECM during the EVAP leak
check.
SENSOR UNIT
ASSEMBLY
TERMINAL
EVAP Two Way Valve and EVAP Bypass Solenoid
Valve
The EVAP two way valve is installed between the fuel
tank and the EVAP canister line.
The EVAP two way valve sends fuel vapor to the EVAP
canister corresponding to the pressure inside the fuel
tank. It also relieves excess vacuum in the tank by
allowing fresh air to be drawn into the tank through the
EVAP canister.
The EVAP bypass solenoid valve opens to bypass the
two way valve during the EVAP leak check.
EVAP BYPASS
SOLENOID VALVE
To FTP SENSOR
~·~r~~~j;;=i3
To EVAP
CANISTER
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AJI,:.'Jt _ _ _
VALVE
DIAPHRAGM
VALVE
(conl'd)
11-35