GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2007 🢒 G6 🢒 Safety and Security 🢒 Supplemental Inflatable Restraints 🢒 DTC P0455

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 provides an overview of each diagnostic category.

DTC Descriptor

DTC P0455: Evaporative Emission (EVAP) System Large Leak

Circuit/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 solenoid valve OPEN and the EVAP vent solenoid 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 solenoid valve closed, sealing the system, and monitors the FTP sensor input in order to determine the EVAP system vacuum level. 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 solenoid valves.

Control Module Command

EVAP Canister Purge Solenoid Valve

EVAP Canister Vent Solenoid Valve

ON

Open

Closed/Not Venting

OFF

Closed

Open/Venting

Conditions for Running the DTC
    • DTCs P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0125, P0442, P0443, P0446, P0449, P0452, P0453, P1111, P1112, P1114, P1115, P1125, P1135, P1351, P1352, P1361, P1362, P1516, P1548, P2101, P2107, P2108, P2119, P2120, P2125, P2135, P2138 are not set.
    • The engine is running.
    • 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 start-up engine coolant temperature (ECT) is between 4-30°C (39-86°F).
    • The start-up 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.
    • DTC P0455 runs once per cold start within 10 minutes of start-up.

Conditions for Setting the DTC

The EVAP system is not able to achieve or maintain vacuum for up to 4 times during the diagnostic test.

Action Taken When the DTC Sets

DTC P0455 is a Type B DTC.

Conditions for Clearing the MIL/DTC

DTC P0455 is a Type B DTC.

Diagnostic Aids
    • A loose, missing, incorrect, or damaged fuel fill cap may cause this DTC to set.
    • To help locate intermittent leaks, use the J 41413-200 to introduce smoke into the EVAP system. Move all EVAP components while observing smoke with a 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.
    • To improve the visibility of the smoke exiting the EVAP system, observe the suspected leak area from different angles with a high intensity white light.

Reference Information

Schematic Reference

    •  Evaporative Emissions Hose Routing Diagram
    •  Engine Controls Schematics

Connector End View Reference

    •  Engine Control Module Connector End Views
    •  Engine Controls Component Views

Electrical Information Reference

    •  Circuit Testing
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

    •  Scan Tool Data List
    •  Scan Tool Output Controls

Special Tools Required

    • J 41413-200 Evaporative Emission System Tester (EEST)
    • GE-41415-50 Fuel Tank Cap Adapter

Circuit/System Testing

Important: 

   • Larger volume fuel tanks and/or those with lower fuel levels may require several minutes for the floating indicator to stabilize.
   • Refer to the J 41413-200 (J 41413-100) operation manual for detailed instructions.

  1. Using the GE-41415-50 , connect the J 41413-200 to the vehicle filler neck.
  2. Use the flow meter on the J 41413-200 , calibrated to 0.51 mm (0.020 in) to determine that there is no leak in the EVAP system.
    3. ⇒If a leak is detected use the J 41413-200 to apply smoke to the EVAP system at the service port or the filler neck until the leak is located.
  3. Start the engine with the J 41413-200 connected to the fuel filler neck.
  4. Allow the engine to idle.
  5. Use the Purge/Seal function to seal the system with a scan tool.
  6. Command the EVAP canister purge solenoid valve to 30 percent.
  7. The vacuum/pressure gage on the J 41413-200 and the FTP parameter on the scan tool should both show vacuum.
    8. ⇒If the vacuum/pressure gage on the J 41413-200 does not show vacuum, check for a restricted purge path.
  8. Vacuum should increase on the gage of the J 41413-200 and scan tool until it reaches approximately 16 inches  H2O, or until the vacuum reaches the abort limit on the scan tool.
    9. ⇒If the difference between the FTP parameter on a scan tool and the vacuum/pressure gage on the J 41413-200 was more than 1 inch, replace the FTP sensor.
    ⇒If the Fuel Tank Pressure Sensor parameter on a scan tool display was less than 3.2 volts, replace the FTP sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Fuel Tank Pressure Sensor Replacement
    •  Control Module References for engine control module (ECM) replacement, setup, and programming