P1441

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, P0117, P0118, P0122, P0123, P0125, 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
The PCM detects vacuum during a non-purge condition.

ACTION TAKEN WHEN THE DTC SETS
^ The control module illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
^ The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
^ A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
^ A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
^ Use a scan tool in order to clear the MIL and the DTC.

DIAGNOSTIC AIDS
An intermittent condition could be caused by an improperly installed or damaged EVAP canister purge valve or a temporary blockage in the EVAP canister purge valve. To repair a blockage in the EVAP system refer to Fuel System Cleaning. Service and Repair

TEST DESCRIPTION

Steps 1-11:

The numbers below refer to the step numbers on the diagnostic table.
3. This step checks for a leaking purge valve.
4. Removing the fuel fill cap will equalize the pressure inside the tank with the atmospheric pressure. At 0 inches of H2O, the FTP sensor should be near 1.5 volts. If it is not, there is a concern with the sensor or related wiring.
10. Because of temperature restrictions use the Service Bay Test in order to complete the test procedure.