Evaporative Emission (Evap) Controls - Honda CR-V 1997 Service Manual

Evaporative Emission (EVAP) Controls
Description:
The evaporative emission controls are designed to minimize the amount of fuel vapor escaping to the atmosphere. The
system consists of the following components:
A. Evaporative Emission (EVAP) Control Canister
An EVAP control canister is used for the temporary storage of fuel vapor until the fuel vapor can be purged from the
EVAP control canister into the engine and burned.
B. Vapor Purge Control System
EVAP control canister purging is accomplished by drawing fresh air through the EVAP control canister and into a port
on the intake manifold. The purging vacuum is controlled by the EVAP purge control solenoid valve.
EVAP PURGE CONTROL SOLENOID VALVE DUTY CONTROLLED AFTER
STARTING ENGINE
ENGINE COOLANT TEMPERATURE ABOVE 154°F 168°C)
C. Fuel Tank Vapor Control System
When fuel vapor pressure in the fuel tank is higher than the set value of the EVAP two way valve, the valve opens and
regulates the flow of fuel vapor to the EVAP control canister.
'97 model:
EVAP
TWOWAV
VALVE
EVAP
PURGE
CONTROL
SOLENOID
VALVE
From
No. 15
BLK! ... ALTERNATOR
. - - - - - - V E L
- - - - - - - - - < ...
SP SENSOR (7.5 AI
rr=======;~C;===J1 rr==~!JI!I
(in the under-dash
EVAP fuse/relay box)
CONTROL
CANISTER
~
FRESH AIR
-=-----,: ------------
FUEL
TANK
EVAPVALVE
FUEL TANK
FUEL
FILL
CAP
L
_ _ _ _
RED/ _ _ _ _ --¢
VEL
PCM VARIOUS
SENSOR
BLK
~
INTAKE MANIFOLD
Icont'd)
11-203