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. This DTC will set if the vacuum in the EVAP system is more than a predetermined value within a predetermined time.

CONDITIONS FOR RUNNING THE DTC
^ DTCs P0107, P0108, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0125, P0440, P0442, P0443, P0446, P0449, P0452, P0453, P1111, P1112, P1114, P1115, P1121, or P1122 are not active.
^ The system voltage is between 10-18 volts.
^ The startup Engine Coolant Temperature (ECT) is between 4-30°C (39-86°F).
^ The startup 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 fuel tank level is between 15-85 percent.
^ The Barometric Pressure (BARO) is more than 75 kPa.
^ 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) on the second consecutive ignition cycle that the diagnostic runs and fails.
^ The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the 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
The EVAP system tests run when the engine is first started and meets the Conditions for Running the DTC. 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 Evaporative Emission (EVAP) System Cleaning. Service and Repair

TEST DESCRIPTION

Steps 1-7:

The number below refers to the step number on the diagnostic table.
6. Because of temperature restrictions use the Service Bay Test to complete the test procedure.