Suzuki XL7 2007 Service Manual page 220

1A-115 Engine General Information and Diagnosis:
Component Testing
1. Ignition OFF, disconnect the harness connector at
the EVAP purge solenoid. Test for 15-20 ohms of
resistance between the terminals of the EVAP purge
solenoid.
➢ If the resistance is not within the specified range,
replace the EVAP purge solenoid.
2. Test for infinite resistance between each terminal of
the EVAP purge solenoid and the EVAP purge
solenoid housing.
➢ If less than infinite resistance, replace the EVAP
purge solenoid.
Repair Instructions
Perform the "Diagnostic Repair Verification - Vehicle
Diagnostic Information: " after completing the diagnostic
procedure.
• "Evaporative Emission Canister Purge Solenoid Valve
Replacement: "
• "Control Module References: " for ECM replacement,
setup, and programming
DTC P0446
Diagnostic Instructions
• Perform the "Diagnostic System Check - Vehicle
Diagnostic Information: " prior to using this diagnostic
procedure.
• "Strategy Based Diagnosis: "
• "Diagnostic Procedure Instructions - Vehicle
Diagnostic Information: "
DTC Descriptor
DTC P0446: Evaporative Emissions (EVAP) Vent
System Performance
Circuit/System Description
A restricted or blocked evaporative emission (EVAP)
vent path is detected by the control module commanding
the purge valve ON (open) and the vent valve ON
(closed) allowing a vacuum to be applied to the EVAP
system. Once a calibrated vacuum level has been
reached, the control module commands the purge valve
OFF (closed) and the vent valve OFF (open) while
monitoring the fuel tank pressure (FTP) sensor for a
decrease in vacuum.
The following table illustrates the relationship between
the ON and OFF states, and the OPEN or CLOSED
states of the EVAP canister purge and vent valves.
Control Module EVAP Canister
Command Purge Valve
ON
OFF Closed
EVAP Canister
Vent Valve
Open Closed
Open
Conditions for Running the DTC
• Before the ECM can report DTC P0446 failed, DTCs
P0451, P0452, and P0453 must run and pass.
• DTCs P0100, P0101, P0102, P0103, P0111, P0112,
P0113, P0116, P0117, P0118, P0119, P0121, P0122,
P0123, P0125, P0128, P0221, P0222, P0223, P0443,
P0449, P0451, P0452, P0453, P0458, P0459, P0496,
P0498, P0499, P0560, P0562, P0563, P0722, P0723,
P2122, P2123, P2127, P2128 and P2138 are not set.
• The ignition voltage is more than 10.5 volts.
• The fuel system is operating in Closed Loop.
• The engine run time is more than 10 minutes or the
fuel trim is stable.
• The engine is idling.
• The FTP is between -18.7 and +7.5 mm Hg (-10.0 and
+4.0 in. H2O).
• The ambient air temperature (AAT) is between −7 and
32°C (19-90°F).
• The ECT and the AAT are within 10°C (18°F) of each
other at engine start-up.
• The fuel level is between 12-88 percent.
• The vehicle speed sensor (VSS) is less than 2 km/h (3
mph).
• The above conditions exist for more than 5 seconds.
• DTC P0446 will attempt to run up to 10 times or until
the test completes successfully once per ignition
cycle.
Conditions for Setting the DTC
• The FTP is less than -6.0 mm Hg (-3.2 in. H2O).
• The condition is present for more than 4 seconds or a
cumulative of 50 seconds.
Action Taken When the DTC Sets
DTC P0446 is a Type B DTC.
Conditions for Clearing the DTC
DTC P0446 is a Type B DTC.
Diagnostic Aids
An intermittent condition could be caused by a damaged
EVAP vent housing, a temporary blockage at the EVAP
vent valve inlet or a pinched vent hose. A blockage in the
vent system will also cause a poor fuel fill problem.