P1441

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




The table illustrates the relationship between the ON and OFF states, and the Open or Closed states of the EVAP canister purge and vent valves.

CONDITIONS FOR RUNNING THE DTC
^ DTCs P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0121, P0122, P0123, P0125, P0440, P0442, P0446, P0443, P0449, P0452, P0453, P1106. P1107, P1111, P1112, P1114, P1115, P1121, or P1122 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).
^ The vehicle speed sensor (VSS) is less than 121 km/h (75 mph).

CONDITIONS FOR SETTING THE DTC
The control module detects vacuum during a non-purge condition.

ACTION TAKEN WHEN THE DTC SETS
^ The control module will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test ran and failed.
^ The control module will store conditions which were present when the DTC set as Freeze Frame and Failure Records data.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The control module will turn OFF the MIL during the third consecutive trip in which the diagnostic ran and passed.
^ The History DTC will clear after 40 consecutive warm-up cycles without a malfunction.
^ The DTC can be cleared with a scan tool.

DIAGNOSTIC AIDS
An intermittent condition could be caused by an improperly installed or damaged EVAP canister purge valve or by a temporary blockage in the EVAP canister purge valve. In order to repair a blockage in the EVAP system, refer to Evaporative Emission (EVAP) System Cleaning.

TEST DESCRIPTION

Steps 1-7:

The number below refers to the step number on the diagnostic table.
4. This step tests for a faulty EVAP canister purge valve. Because of temperature restrictions, use the Service Bay Test in order to complete the test procedure.