GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2003 🢒 Corvette 🢒 Engine 🢒 Engine Controls - 5.7L 🢒 DTC P0440
Table 1: DTC P0440

System Description

The control module tests the evaporative emission (EVAP) system for a large leak. The control module monitors the fuel tank pressure (FTP) sensor signal to determine the EVAP system vacuum level. When the conditions for running are met, the control module commands the EVAP canister purge valve OPEN and the EVAP vent valve CLOSED . This allows engine vacuum to enter the EVAP system. At a calibrated time, or vacuum level, the control module commands the EVAP canister purge valve closed, sealing the system, and monitors the FTP sensor input in order to determine the EVAP system vacuum level. If the system is unable to achieve the calibrated vacuum level, or the vacuum level decreases too rapidly, this DTC sets.

The following table illustrates the relationship between the ON and OFF states, and the OPEN or CLOSED states of the EVAP canister purge and vent valves.

Control Module Command

EVAP Canister Purge Valve

EVAP Canister Vent Valve

ON

Open

Closed

OFF

Closed

Open

Conditions for Running the DTC
    • DTCs P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0125, P0443, P0449, P0452, P0453, P1112, P1114, P1115, P1120, P1133, P1134, P1153, P1154, P1220, or P1221 are not set.
    • The ignition voltage is between 10-18 volts.
    • The barometric pressure 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) of each other.
    • The vehicle speed sensor (VSS) is less than 121 km/h (75 mph).

Conditions For Setting the DTC

The EVAP system is not able to achieve or maintain vacuum during the diagnostic test.

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.
    • Clear the MIL and the DTC with a scan tool.

Diagnostic Aids
    • To help locate intermittent leaks, use the J 41413-200 Evaporative Emissions System Tester (EEST) to introduce smoke into the EVAP system. Move all EVAP components while observing smoke with the J 41413-SPT High Intensity White Light.
    • A temporary blockage in the EVAP purge solenoid, purge pipe or EVAP canister could cause an intermittent condition. Inspect and repair any restriction in the EVAP system.
    • To improve the visibility of the smoke exiting the EVAP system, observe the suspected leak area from different angles with the J 41413-SPT .
    • Reviewing the Failure Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.
    • For intermittent conditions refer to Intermittent Conditions .

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step verifies that a failure condition is active.

    2.

  2. Introducing smoke in 15 second intervals may allow smaller leak areas to be more noticeable. When the system is less pressurized, the smoke will sometimes escape in a more condensed manner.

  3. This step verifies proper operation of the FTP sensor.

    4.

  4. A normal operating FTP sensor should increase above 5 inches of H2O and Stop between 6 inches of H2O and 7 inches of H2O.

    5.

  5. This step tests the EVAP purge solenoid vacuum source between the EVAP purge solenoid and the Intake manifold for restrictions or blockages.

DTC P0440

Step

Action

Values

Yes

No

Schematic Reference: Evaporative Emissions Hose Routing Diagram

1

Did you perform the Diagnostic System Check-Engine Controls?

--

Go to Step 2

Go to Diagnostic System Check - Engine Controls

2

  1. Observe the Freeze Frame/Failure Records for this DTC.
  2. Perform the Service Bay Test. Refer to Service Bay Test .

Does the scan tool indicate that the Service Bay Test passed?

--

Go to Diagnostic Aids

Go to Step 3

3
  1. Inspect the evaporative emission (EVAP) system for the following conditions:
    2. • Loose, missing, or damaged service port schrader valve
    • Loose, incorrect, missing, or damaged fuel fill cap
    • A damaged EVAP purge solenoid.
  2. Raise the vehicle on a hoist. Refer to Lifting and Jacking the Vehicle in General Information.
  3. Inspect the EVAP system for the following conditions:
    4. • Disconnected, improperly routed, kinked, or damaged EVAP pipes and hoses
    • A damaged EVAP vent solenoid or EVAP canister

Did you find and correct the condition?

--

Go to Step 19

Go to Step 4

4

Important: Ensure that the vehicle underbody temperature is similar to the ambient temperature and allow the surrounding air to stabilize before starting the diagnostic procedure. The system flow will be less with higher temperatures.

  1. Turn OFF the ignition.
  2. Connect the J 41413-200 Evaporative Emissions System Tester (EEST) power supply clips to a known good 12-volt source.
  3. Install the J 41415-40 Fuel Tank Cap Adapter to the fuel fill pipe.
  4. Install the fuel fill cap to the J 41415-40
  5. Connect the J 41413-200 nitrogen/smoke supply hose to the J 41415-40 .
  6. Turn ON the ignition with the engine OFF.
  7. Command the EVAP vent solenoid closed with a scan tool.
  8. Turn the nitrogen/smoke valve on the J 41413-200 control panel to SMOKE.
  9. Use the remote switch to introduce smoke into the EVAP system.
  10. Use the J 41413-VLV EVAP Service Port Vent Fitting to open the EVAP service port.
  11. Remove the J 41413-VLV once smoke is observed.
  12. Continue to introduce smoke into the EVAP system for an additional 60 seconds.
  13. Inspect the entire EVAP system for exiting smoke with the J 41413-SPT High Intensity White Light.
  14. Continue to introduce smoke at 15 second intervals until the leak source has been located.

Did you locate and repair a leak source?

--

Go to Step 19

Go to Step 5

5
  1. Disconnect the J 41415-40 from the fuel fill pipe.
  2. Install the fuel fill cap to the fuel fill pipe.
  3. Connect the J 41413-200 nitrogen/smoke supply hose to the EVAP service port.
  4. Use the remote switch to introduce smoke into the EVAP system.
  5. Inspect the entire EVAP system for exiting smoke with the J 41413-SPT .
  6. Continue to introduce smoke at 15 second intervals until the leak source has been located.

Did you locate and repair a leak source?

--

Go to Step 19

Go to Step 6

6

  1. Use the remote switch to stop introducing smoke.
  2. Install the J 41415-40 to the fuel fill pipe.
  3. Connect the J 41413-200 nitrogen/smoke supply hose and vehicle fuel fill cap to the J 41415-40 .
  4. Command the EVAP vent solenoid open with a scan tool.
  5. Compare the Fuel Tank Pressure (FTP) parameter with a scan tool to the J 41413-200 pressure/vacuum gage.

Is the scan tool Fuel Tank Pressure parameter within the specified value of the J 41413-200 pressure/vacuum gage?

1 in H2O

Go to Step 7

Go to Step 16

7

  1. Seal the EVAP system using the EVAP Purge/Seal function with a scan tool.
  2. Turn the nitrogen/smoke valve on the J 41413-200 control panel to NITROGEN.
  3. Use the J 41413-200 to pressurize the EVAP system to the first specified value.

Is the Fuel Tank Pressure sensor parameter more than the second specified value?

10 in H2O

5 in H2O

Go to Step 8

Go to Step 16

8
  1. Use the remote switch to stop introducing nitrogen into the EVAP system.
  2. Increase the EVAP purge solenoid to 100 percent.

Is the Fuel Tank Pressure parameter less than the specified value?

1 in H2O

Go to Diagnostic Aids

Go to Step 9

9

Disconnect the EVAP purge vacuum source from the EVAP purge solenoid.

Is the Fuel Tank Pressure parameter less than the specified value?

1 in H2O

Go to Step 13

Go to Step 10

10

Disconnect the EVAP purge pipe from the EVAP purge solenoid.

Is the Fuel Tank Pressure parameter less than the specified value?

1 in H2O

Go to Step 17

Go to Step 11

11

Disconnect the EVAP purge pipe at the EVAP canister.

Is the Fuel Tank Pressure parameter less than the specified value?

1 in H2O

Go to Step 15

Go to Step 12

12

Disconnect the EVAP vapor pipe at the EVAP canister.

Is the Fuel Tank Pressure parameter less than the specified value?

1 in H2O

Go to Step 18

Go to Step 14

13

Repair the pinched or obstructed EVAP purge solenoid vacuum source

Did you complete the repair?

--

Go to Step 19

--

14

Repair the pinched or obstructed EVAP vapor pipe.

Did you complete the repair?

--

Go to Step 19

--

15

Repair the restriction in the EVAP purge pipe. Refer to Evaporative Emission System Hoses/Pipes Replacement .

Did you complete the repair?

--

Go to Step 19

--

16

Replace the FTP sensor. Refer to Fuel Tank Pressure Sensor Replacement .

Did you complete the replacement?

--

Go to Step 19

--

17

Replace the EVAP purge solenoid. Refer to Evaporative Emission Canister Purge Solenoid Valve Replacement .

Did you complete the replacement?

--

Go to Step 19

--

18

Replace the EVAP canister. Refer to Evaporative Emission Canister Replacement .

Did you complete the replacement?

--

Go to Step 19

--

19

Perform the Service Bay Test. Refer to Service Bay Test .

Does the scan tool indicate that the Service Bay Test passed?

--

Go to Step 20

Go to Step 3

20

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

--

Go to Diagnostic Trouble Code (DTC) List

System OK