Nissan Altima L32. Manual - part 242
EVAPORATIVE EMISSION SYSTEM
EC-89
< FUNCTION DIAGNOSIS >
[QR25DE FOR CALIFORNIA]
C
D
E
F
G
H
I
J
K
L
M
A
EC
N
P
O
*1: ECM determines the start signal status by the signals of engine speed and battery voltage.
*2: This signal is sent to the ECM through CAN communication line.
SYSTEM DESCRIPTION
The evaporative emission system is used to reduce hydrocarbons emitted into the atmosphere from the fuel
system. This reduction of hydrocarbons is accomplished by activated charcoals in the EVAP canister.
The fuel vapor in the sealed fuel tank is led into the EVAP canister which contains activated carbon and the
vapor is stored there when the engine is not operating or when refueling to the fuel tank.
The vapor in the EVAP canister is purged by the air through the purge line to the intake manifold when the
engine is operating. EVAP canister purge volume control solenoid valve is controlled by ECM. When the
engine operates, the flow rate of vapor controlled by EVAP canister purge volume control solenoid valve is
proportionally regulated as the air flow increases.
EVAP canister purge volume control solenoid valve also shuts off the vapor purge line during decelerating.
Sensor
Input signal to ECM
ECM function
Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)
Engine speed*
1
EVAP canister
purge flow control
EVAP canister purge vol-
ume control solenoid valve
Mass air flow sensor
Amount of intake air
Engine coolant temperature sensor
Engine coolant temperature
Battery
Battery voltage*
1
Throttle position sensor
Throttle position
Accelerator pedal position sensor
Accelerator pedal position
Air fuel ratio (A/F) sensor 1
Density of oxygen in exhaust gas
(Mixture ratio feedback signal)
Fuel tank temperature sensor
Fuel temperature in fuel tank
EVAP control system pressure sensor
Pressure in purge line
Combination meter
Vehicle speed*
2