P1441

DESCRIPTION
This Diagnostic Trouble Code (DTC) tests for undesired intake manifold vacuum flow to the Evaporative Emissions (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
1. DTC P0440, P0442, P0446, P0107. P0108, P0110, P0112, P0113, P0115, P0117, P0118, P0121, P0122, P0123, P0125, P0443, P0449, P0452, P0453, P1106. P1107, P1111, P1112, P1114, P1115, P1121 and P1122 not active.
2. The system voltage is between 10-18 volts.
3. The startup ECT is between 4-30°C (39-86°F).
4. The startup Intake Air Temperature (IAT) is between 4-30°C (39-86°F).
5. The fuel tank level is between 15-85 percent.
6. The Barometric Pressure (BARO) is more than 75 kPa (10.8 psi).
7. The Vehicle Speed Sensor (VSS) is less than 120 km/h (75 mph).

CONDITIONS FOR SETTING THE DTC
The PCM detects vacuum during a non purge conditions.

ACTION TAKEN WHEN THE DTC SETS
^ The PCM illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
^ The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the PCM stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure. The PCM writes the conditions to the Freeze Frame and updates the Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
^ A last test failed, or the current DTC, clears when the diagnostic runs and does not fail.
^ A history DTC clears after 40 consecutive warm-up cycles, if failures are not reported by this or any other emission related diagnostic.
^ Use a scan tool in order to clear the MIL/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.

TEST DESCRIPTION

Steps 1-9:

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