The ECM/PCM closes the Canister Close Valve (CCV) at the charcoal canister to seal off the evaporative emission system and then opens purge control valve (PCSV) to generate a vacuum in the fuel tank. After vacuum generation, the ECM/PCM measures pressure differential curve in the fuel tank and sets DTC P0442 or P0456 if the vacuum generated within a monitoring period increases above a defined threshold.If same error code is set in the next driving cycle, the ECM/PCM illuminates the MIL.
Item | Detecting Condition | Possible cause |
DTC Strategy |
•
Check Fuel Tank Pressure with CCV and PCSV closed after the P0455 monitormonitor | 1. Fuel filler cap damage or missing 2. Faulty or damaged fuel filler pipe 3. Leaking, disconnected or plugged fuel vapor lines 4. Faulty CCV 5. Faulty PCSV 6. Faulty Canister 7. Faulty Fuel Tank Pressure Sensor (FTPS) |
EnableConditions |
•
CCV Close
•
CPSV Close
•
Common Conditions for Evap.System Monitoring | |
Threshold value |
•
Fuel Tank Pressure gradient > 44~60 Pa/sec | |
Diagnosis Time |
•
15 sec | |
MIL On Condition |
•
2 Driving Cycles |
