P0448

DTC P0448 EVAPORATIVE EMISSION CONTROL SYSTEM VENT CONTROL CIRCUIT SHORTED

1. OUTLINE OF DIAGNOSIS
Detect open or short circuit of the drain valve.
Judge as NG when the ECM output level differs from the actual terminal level.

2. COMPONENT DESCRIPTION
The drain valve adjusts the pressure in the canister by introducing/extracting air when pressure differences occur in the canister with the atmospheric pressure.




3. ENABLE CONDITIONS

4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.

5. DIAGNOSTIC METHOD




Abnormality Judgment
Judge as NG when the continuous time of completing the malfunction criteria becomes more than 2.5 seconds.




Normality Judgment
Judge as OK and clear the NG when the malfunction criteria are met.

6. DTC CLEAR CONDITION
- When the OK idling cycle is completed 40 times in a row
- When "Clear Memory" is performed

7. MALFUNCTION INDICATOR LIGHT CLEAR CONDITIONS
- When the OK driving cycle is completed 3 times in a row
- When "Clear Memory" is performed

8. FAIL SAFE
Pressure control solenoid valve control: Open the pressure control solenoid valve

9. ECM OPERATION AT DTC SETTING
Memorize the freeze frame data. (For test mode $02)