GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provide an overview of each diagnostic category.

DTC Descriptor

DTC P0441 : Evaporative Emissions (EVAP) System Continuous Purge Flow.

Circuit Description

This DTC tests for continuous intake manifold vacuum flow to the Evaporative Emission (EVAP) System. The control module seals the EVAP system by commanding the EVAP canister purge solenoid valve Closed and the EVAP canister vent solenoid valve Closed. 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 greater than a predetermined value within a predetermined time, this DTC sets.

FTP Sensor Signal Voltage

Fuel Tank Pressure

High, Approximately 1.5 Volts or More

Negative Pressure/Vacuum

Low, Approximately 1.5 Volts or Less

Positive Pressure

Conditions for Running the DTC

    • DTCs P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0122, P0123, P0131, P0132, P0133, P0137, P0138, P0140, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, P0277, P0300, P0402, P0404, P0405, P0406, P0452, P0453, P0462, P0463, P0501, and P2422 are not set.
    • The ignition 1 voltage is between 11-16 volts.
    • The barometric pressure (BARO) is greater than 72 kPa.
    • The engine coolant temperature (ECT) is greater than 70°C (158°F).
    • The estimated ambient air temperature is greater than 10°C (50°F).
    • The purge enable time is greater than 15 seconds.
    • The engine run time is greater than 590 seconds.
    • The fuel tank pressure is greater than -7.50 mmHg (-4.0 inH2O) and less than +2.25 mmHg (+1.2 inH2O).
    •  The fuel level is between 14-87 percent.
    • The engine is idling.
    • The vehicle speed is less than 2 km/h (1 mph).
    • DTC P0441 runs once an ignition cycle when the above conditions are met.

Conditions for Setting the DTC

The FTP sensor indicates vacuum during a non-purge condition.

Action Taken When the DTC Sets

DTC P0441 is a Type A/B DTC.

Conditions for Clearing the DTC

DTC P0441 is a Type A/B DTC.

Diagnostic Aids

    • Observe the Freeze Frame/Failure Records vehicle mileage since the diagnostic test last failed may help determine how often the condition occurs that caused the DTC to set. This may assist in diagnosing the condition.
    • The EVAP system tests run when 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 solenoid valve , or by a temporary blockage or restriction in the EVAP canister purge solenoid valve.

Reference Information

Schematic Reference

Evaporative Emissions Hose Routing Diagram

Description and Operation:

Evaporative Emission Control System Description

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

    •  Scan Tool Data List
    •  Scan Tool Data Definitions
    •  Scan Tool Output Controls

Special Tools Required

    • J 41413-300 EVAP Cap and Plug Kit
    • J 23738-A Hand Vacuum Pump

Circuit/System Testing

  1. Ignition ON, loosen the fuel fill cap. Verify the FTP sensor parameter is 0 mmHg (0 inches H20).
  2. If not at the specified value, replace the FTP sensor.
  3. Disconnect the purge line from the EVAP purge solenoid valve and connect a J 23738-A hand vacuum pump.
  4. Verify that the solenoid can hold 10 inches of vacuum for 30 seconds.
  5. If the vacuum decreases, replace the EVAP purge solenoid valve.

Repair Instructions

Evaporative Emission Canister Purge Solenoid Valve Replacement

Repair Verification

  1. Disconnect the EVAP vent line from the vent solenoid and seal it, using a suitable plug from the J 41413-300 .
  2. Start the engine and Increase the engine idle to 1,200-1,500 RPM.
  3. Verify the scan tool FTP sensor parameter is -1 to +1 in H2O.
  4. Clear the DTCs with a scan tool.