The evaporative emission control system prevents hydrocarbon (HC) vapors from the fuel tank from escaping into the atmosphere where they could form photochemical smog. Gasoline vapors are collected in the charcoal canister. The ECM controls the Purge Control Solenoid Valve (PCSV) to purge any collected vapors from the canister back to the engine for combustion. This valve is actuated by the purge control signal from the ECM and controls fuel vapor from the canister to the intake manifold.
If there is Open in PCSV circuit, ECM sets DTC P0444.
Item | Detecting Condition | Possible cause |
DTC Strategy |
•
Circuit check, open |
•
Poor connection
•
Open or short to ground in harness
•
PCSV
•
ECM |
Enable Conditions |
•
- | |
Threshold value |
•
Open | |
Diagnosis Time |
•
Continuous | |
MIL On Condition |
•
2 driving cycles |
Item | Coil resistance(Ω) |
PCSV | 16 ± 2Ω ( at 20℃/ 68℉) |
Fig 1) Normal waveform of PCSV under control condition.
The Purge Control Solenoid Valve(PCSV) is open or closed by ECM and vacuum of intake manifold. At opening, fuel vapor from canister enters into intake manifold. To prevent vacuum from forming inside canister, ECM controls to open it. This photo shows the signal waveform of PCSV operating normally.
