P0442

DTC P0442
Evaporative control system - small leak detected Drive cycle C:Signal out of range - below minimum.

Possible causes by suggested order of priority:
^ Leaking fuel filler cap.
^ Leaking vent seal valve.
^ Leaking tank protective valve.
^ Faulty or missing hose clamp or poor seal.
^ Poor seal on fuel tank pressure sensor.
^ Fuel tank pressure sensor fault.

Leaking Fuel Filler Cap.
CHECK THE FOLLOWING:
^ Check fuel filler cap for any visible cause of leakage.
^ Check fuel filler cap seal for contamination.
^ Check fuel filler cap by substitution with known good unit.
POSSIBLE FAULTS
^ Faulty fuel filler cap.
^ Fuel filler cap has poor seal.

Leaking Vent Seal Valve.
CHECK THE FOLLOWING:
^ Check purge cannister vent seal valve for any visible signs of leakage.
^ Check vent seal valve for contamination with charcoal from purge can.
^ Check vent seal valve by substitution with known good unit.
^ Check vent seal valve attachment to purge cannister for soundness.
POSSIBLE FAULTS
^ Faulty purge cannister vent seal valve.
^ Purge cannister vent seal valve contaminated.
^ Purge cannister vent seal valve attachment to purge cannister leaking.

Leaking Tank Protective Valve.
CHECK THE FOLLOWING:
^ Check fuel tank with suitable pressure test equipment.
POSSIBLE FAULTS
^ Faulty fuel tank pressure relief valve.

Faulty Or Missing Hose Clamp Or Poor Seal.
CHECK THE FOLLOWING:
^ All hose couplings and clamps in evaporative loss system.
POSSIBLE FAULTS
^ Leakage at hose coupling to due faulty or missing clamp.

Poor Seal On Fuel Tank Pressure Sensor.
CHECK THE FOLLOWING:
^ Attachment of fuel tank pressure sensor to fuel tank.
^ Substitute pressure sensor for known good unit.
POSSIBLE FAULTS
^ Faulty seal at fuel tank pressure sensor.
^ Faulty fuel tank pressure sensor.

Fuel Tank Pressure Sensor Fault.
CHECK THE FOLLOWING:
^ Pressure sensor reads close to zero with filler cap removed.
^ If equipment available pressurize the tank and check that the reading on the sensor is accurate.
POSSIBLE FAULTS
^ Faulty fuel tank pressure sensor.