P1441

Diagnostic Chart:

Schematic:

CIRCUIT DESCRIPTION
The evaporative system includes the following components:
^ The fuel tank
^ The EVAP canister vent valve
^ The fuel pipes and hoses
^ The fuel cap
^ The EVAP vapor lines
^ The EVAP purge lines
^ The evaporative emission canister
^ The EVAP purge valve

The PCM tests the EVAP system for the following conditions:
^ Large and small leaks (P0440 and P0442)
^ Excess vacuum (P0446)
^ Purge flow during non-commanded conditions (P1441)
^ Fuel pressure sensor and fuel level sensor faults (P0452, P0453, P0461, P0462 and P0463)
^ EVAP purge and vent valve solenoid malfunctions (P0443 and P0449)

At the appropriate time, the PCM seals the system by turning the EVAP purge OFF, and the canister vent valve ON (both valves closed). The PCM uses the input from the fuel tank pressure sensor to monitor the system vacuum. If the PCM detects an increase in system vacuum (continuous purge condition), the PCM will set DTC P1441. Any of the following conditions will cause DTC P1441 to set:
^ EVAP purge valve leaking or damaged.
^ EVAP purge valve control circuit grounded.

CONDITIONS FOR RUNNING THE DTC
^ No IAT, MAP, TP, HO2S, VSS, ECT sensor DTC's set.
^ DTC P0125 is inactive.
^ Fuel level is between 15 and 85 percent.
^ System voltage is between 10-18 volts.
^ IAT is between 4°C-30°C (39°F-86°F).
^ ECT is less than 32°C (89°F).
^ BARO is greater than 72 kPa.

CONDITIONS FOR SETTING THE DTC
^ Fuel tank vacuum is greater than 7 inches of H2O with EVAP purge not commanded.
^ The condition is present for 3 seconds.

ACTION TAKEN WHEN THE DTC SETS

IMPORTANT: Although these diagnostics are considered type A, they act like type B diagnostics under certain conditions. Whenever the EVAP diagnostics report that the system has passed, or the code has been cleared, the diagnostic must fail during two consecutive trips before setting a DTC. The initial failure is not reported to the diagnostic manager or displayed on the scan tool.
^ The PCM will illuminate the Malfunction Indicator Lamp (MIL) after the second consecutive trip in which the diagnostic test has been run and failed.
^ The PCM will store conditions which were present when the DTC set as Freeze Frame and Fail Records data.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The PCM will turn the MIL OFF after the third consecutive trip in which the diagnostic runs and passes.
^ The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
^ The DTC can be cleared by using the scan tool Clear DTC Information function.

DIAGNOSTIC AIDS

IMPORTANT: An accurate indication of fuel level is required for the PCM to properly RUN this diagnostic. Always diagnose fuel level sensor DTC's before performing this diagnostic table. Always look for fuel level sensor DTC's stored as History.

Perform a physical inspection of the EVAP system. Inspect for the following conditions:
^ A loose, missing, defective, or incorrect fuel tank cap
^ Incorrectly routed, kinked, pinched, plugged, or defective EVAP system vacuum and vapor lines
^ A malfunctioning or damaged EVAP vapor canister

Test for charcoal release from the EVAP vapor canister. Refer to EVAP System Cleaning.

If the condition is intermittent, refer to Intermittent Conditions in Symptoms. Intermittent Conditions