Daewoo MATIZ Service Manual page 308

1F – 210 ENGINE CONTROLS
DIAGNOSTIC TROUBLE CODE (DTC) – P0444 EVAP PURGE CONTROL
Circuit Description
The evaporative emission (EVAP) system includes the
following components :
D Fuel tank.
D EVAP vent solenoid.
D Fuel pipes and hoses.
D Fuel vapor lines.
D Fuel cap.
D EVAP canister.
D Purge lines.
D EVAP canister purge valve.
D EVAP service port.
The evaporative emission system is checked by apply-
ing vacuum to the EVAP system and monitoring for a
vacuum decay. The engine control module(ECM) moni-
tors the vacuum level through the fuel tank pressure
sensor signal. At the appropriate time, the EVAP canis-
ter purge valve and the EVAP vent solenoid are turned
on, allowing the engine to draw a small vacuum on the
entire EVAP system. After the desired vacuum level has
been achieved, the EVAP canister purge valve is turned
OFF, sealing the system. If a sufficient vacuum level
cannot be achieved, a large leak is indicated. This can
be caused by the following conditions :
Missing or faulty fuel cap.
Disconnected or faulty fuel tank pressure sensor.
Disconnected, damaged, pinched, or blocked EVAP
purge line.
Disconnected or faulty EVAP canister purge valve.
Disconnected or faulty EVAP vent solenoid.
CIRCUIT NO SIGNAL
Open ignition feed circuit to the EVAP vent or purge so-
lenoid.
Damaged EVAP canister.
Leaking fuel sensor assembly O-ring.
Leaking fuel tank or fuel filler beck.
Any of the above conditions can set DTC P0444.
The test is failed if the tank vacuum is less than 10 in
H20 for 15 seconds and the manifold vacuum integral is
greater than 49512 (proportional to purge mass from the
tank).
Conditions for Setting the DTC
D Intake Air Temperature(IAT) is between 4°C and
34°C(39°F and 93°F).at engine start up.
D Engine Coolant Temperature(ECT) is between 4°C
and 34°C(39°F and 93°F).at engine start up.
D Barometric pressure (BARO) is greater than 68kPA.
D IAT is not more than 8°C(46°F) greater than the ECT
at start up.
D Fuel level is between 10% and 90%.
D The throttle position (TP) sensor is less than or equal
to 100%.
D No fuel slosh, and the change in fuel level percent is
21 counts on 0.125 sec.
D Manifold vacuum is greater than or equal to 10kPA.
D Fuel level or change in tank pressure is less than or
equal to 24.9 in H2O.
D System voltage is between 11V and 16V.
MAA1F240
DAEWOO M-150 BL2