P1441

SYSTEM DESCRIPTION
This diagnostic trouble code (DTC) tests for undesired intake manifold vacuum flow to the evaporative emission (EVAP) system. The powertrain control module (PCM) seals the EVAP system by commanding the EVAP purge valve OFF (closed) and the EVAP vent valve ON (closed). The PCM monitors the fuel tank pressure (FTP) sensor to determine if a vacuum is being drawn on the EVAP system. If the vacuum in the EVAP system is more than a calibrated value within a calibrated time, DTC P1441 will set.

CONDITIONS FOR RUNNING THE DTC
^ DTCs P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0440, P0442, P0446, P0452, or P0453 are not set.
^ The ignition voltage is between 10-18 volts.
^ The barometric pressure (BARO) is more than 75 kPa.
^ The fuel level is between 15-85 percent.
^ The engine coolant temperature (ECT) is between 4-30°C (39-86°F).
^ The intake air temperature (IAT) is between 4-30°C (39-86°F).
^ The start up ECT and IAT are within 9°C (16°F) of each other.
^ The vehicle speed sensor (VSS) is less than 121 km/h (75 mph).

CONDITIONS FOR SETTING THE DTC
A continuous open purge flow condition is detected during the diagnostic test (fuel tank pressure decreases to less than -11 inches H2O).

CONDITIONS FOR CLEARING THE MIL/DTC
^ The PCM will turn the MIL OFF during the first trip in which the diagnostic has been run and passed.
^ The history DTC will clear when the PCM turns OFF the MIL.
^ The DTC can be cleared by using a scan tool.

DIAGNOSTIC AIDS
^ Carbon release from the EVAP canister could cause the purge valve to stick open intermittently. To check for carbon release in the EVAP system, refer to Evaporative Emission (EVAP) System Cleaning.
^ Reviewing the Failure Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.

TEST DESCRIPTION

DTC P1441 - Steps 1-4:

DTC P1441 - Steps 5-11:

The number below refers to the step number on the diagnostic table.
4. This test determines if the EVAP canister purge valve can seal. Any indication of vacuum on the vacuum gage indicates that the EVAP purge valve is not seating properly.