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DRIVEABILITY - NGC
Symptom List:
P0442-EVAP SYSTEM MEDIUM LEAK
P0455-EVAP SYSTEM LARGE LEAK
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be P0442-EVAP SYSTEM MEDIUM
LEAK.
When Monitored and Set Condition:
P0442-EVAP SYSTEM MEDIUM LEAK
When Monitored: Engine Running. Cold start test. Fuel Level greater than 12%. Ambient
Temperature between 4°C and 32°C (39°F and 89°F) Close Loop fuel system. Test runs
when small leak test is maturing.
Set Condition: The PCM activates the EVAP Purge Solenoid to pull the EVAP system into
a vacuum to close the NVLD swtich. Once the NVLD swtich is closed, the PCM turns the
EVAP Pugre solenoid off to seal the EVAP system. If the NVLD switch reopens before the
calibrated amount of time for a Medium leak an error is detected. Two Trip Fault.
P0455-EVAP SYSTEM LARGE LEAK
When Monitored: Engine Running. Cold start test. Fuel Level greater than 12%. Ambient
Temperature between 4°C and 32°C (39°F and 89°F) Close Loop fuel system. Test runs
when small leak test is maturing.
Set Condition: The PCM activates the EVAP Purge Solenoid to pull the EVAP system into
a vacuum to close the NVLD swtich. Once the NVLD switch is closed, the PCM turns the
EVAP Purge solenoid off to seal the EVAP system. If the NVLD switch reopens before the
calibrated amount of time for a Large leak an error is detected. Two Trip Fault.
INTERMITTENT CONDITION
VISUAL AND PHYSICAL INSPECTION
EVAPORATIVE EMISSION LEAK DETECTION
EVAP PURGE SOLENOID OPERATION
NVLD SWITCH OPERATION
POSSIBLE CAUSES
386
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