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For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Epica 🢒 Engine 🢒 Engine Controls - 2.5L (LBK) 🢒 DTC P0455

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 increases too slowly, this DTC sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0455 Evaporative Emission (EVAP) System Large Leak Detected

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, P1449, and P2422 are not set.
    • The ignition 1 voltage is between 11-16 volts.
    • The barometric pressure (BARO) is more than 72 kPa.
    • The engine coolant temperature (ECT) is more than 70°C (158°F).
    • The estimated ambient air temperature is more than 9.75°C (50°C).
    • The purge enable time is more than 15 seconds.
    • The engine run time is more than 590 seconds.
    • The Fuel Tank Pressure is more than -1Kpa and less than .3 Kpa.
    • The fuel level is between 14-87%.
    • The engine is Idling.
    • The vehicle speed is less than 2 km/h (1 mph).
    • DTC P0455 runs once an ignition cycle when the above conditions are met.

Conditions For Setting the DTC

The ECM detects 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. Introducing smoke in 15 second intervals will allow less pressure into the EVAP system. When the system is less pressurized, the smoke will sometimes escape in a more condensed manner.
    • 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 .
    • For an intermittent condition, refer to Intermittent Conditions .

Test Description

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

  1. 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.

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

    3.

  3. A normal operating FTP sensor should increase above 5 inches H20 and stop between 6 inches H20 and 7 inches H20.

    4.

  4. This step applies ignition voltage to the EVAP purge solenoid. The pressure should drop to less than 1 in 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 P0455 Evaporative Emission (EVAP) System Large Leak Detected

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

Important: Larger volume fuel tanks and/or those with lower fuel levels may require several minutes for the floating indicator to stabilize.

  1. Turn the nitrogen/smoke valve to nitrogen.
  2. Connect the nitrogen/smoke hose to the 0.5 mm (0.020 in) test orifice on the bottom-front of the J 41413-200 Evaporative Emissions System Tester (EEST).
  3. Use the remote switch to activate the J 41413-200 .
  4. Align the red flag on the flow meter with the floating indicator. Use the remote switch to de-activate the J 41413-200 .
  5. Install the J 41415-30 Fuel Tank Cap Adapter to the fuel fill pipe.
  6. Remove the nitrogen/smoke hose from the test orifice and install the hose onto the J 41415-30.
  7. Turn ON the ignition, with the engine OFF.
  8. Disconnect the EVAP vent line from the vent solenoid, and seal it, using a suitable plug or a plug from the J 41413-300 EVAP Cap/Plug Kit.
  9. Use the remote switch to introduce nitrogen and fill the EVAP system until the floating indicator stabilizes.
  10. Compare the flow meter's stable floating indicator position to the red flag.

Is the floating indicator below the red flag?

--

Go to Step 7

Go to Step 3

3
  1. Inspect the 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, incorrectly routed, kinked, or damaged EVAP pipes and hoses
    • A damaged EVAP vent valve 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 power supply clips to a known good 12-volt source.
  3. Install the J 41415-30 to the fuel fill pipe.
  4. Connect the J 41413-200 Nitrogen/Smoke Supply Hose to the J 41415-30.
  5. Turn ON the ignition with the engine OFF.
  6. Turn the nitrogen/smoke valve on the J 41413-200 control panel to SMOKE.
  7. With the vent still plugged, use the remote switch to introduce smoke into the EVAP system.
  8. Use the J 41413-VLV EVAP Port Vent Fitting tool to open the EVAP service port.
  9. Remove the J 41413-VLV once the smoke is observed.
  10. Continue to introduce smoke into the EVAP system for an additional 60 seconds.
  11. Inspect the entire EVAP system for exiting smoke with the J 41413-SPT High Intensity White Light.
  12. 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 41415-30 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 41415-30 to the fuel fill pipe.
  3. Connect the J 41413-200 nitrogen/smoke supply hose and vehicle fuel fill cap to the J 41415-30.
  4. Disconnect the plug from the EVAP vent line.
  5. Compare the Fuel Tank Pressure 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 15

7

  1. Disconnect the EVAP vent line from the vent solenoid, and seal it, using a suitable plug or a plug from the J 41413-300 EVAP Cap/Plug Kit.
  2. Turn the nitrogen/smoke valve on the J 41413-200 control panel to NITROGEN.

    3. Important: The fuel tank pressure sensor parameter is limited, so the gage on the J 41413-200 and the fuel tank pressure sensor parameter will not match.

  3. Use the J 41413-200 to pressurize the EVAP system to 10 inches H20.

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

4 in H2O

Go to Step 8

Go to Step 15

8

  1. Use the remote switch to stop introducing nitrogen into the EVAP system.
  2. Disconnect the EVAP purge solenoid electrical connector.
  3. Connect a 5-amp fused jumper wire between the EVAP purge solenoid ignition 1 voltage circuit and battery positive.
  4. Connect a jumper wire to the EVAP purge solenoid control circuit and ground.

Is the Fuel Tank Pressure sensor 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 16

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 17

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

Replace the fuel tank pressure (FTP) sensor.

Did you complete the replacement?

--

Go to Step 19

--

16

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

Did you complete the replacement?

--

Go to Step 19

--

17

Repair the restriction in the EVAP purge pipe.

Did you complete the repair?

--

Go to Step 19

--

18

Replace the EVAP canister.

Did you complete the replacement?

--

Go to Step 19

--

19

Important: Larger volume fuel tanks and/or those with lower fuel levels may require several minutes for the floating indicator to stabilize.

  1. Turn the nitrogen/smoke valve to NITROGEN.
  2. Connect the nitrogen/smoke hose to the 0.5 mm (0.020 in) test orifice on the bottom-front of the J 41413-200 .
  3. Use the remote switch to activate the J 41413-200 .
  4. Align the red flag on the flow meter with the floating indicator. Use the remote switch to de-activate the J 41413-200 .
  5. Install the J 41415-30 to the fuel fill pipe.
  6. Remove the nitrogen/smoke hose from the test orifice and install the hose onto the J 41415-30.
  7. Turn ON the ignition, with the engine OFF.
  8. With the vent still plugged, use the remote switch to introduce nitrogen and fill the EVAP system until the floating indicator stabilizes.
  9. Compare the flow meter's stable floating indicator position to the red flag.

Is the floating indicator below the red flag?

--

Go to Step 20

Go to Step 4

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