2008 Chevrolet Equinox | Equinox, Torrent VIN L Service Manual | Document ID: 1966510
Diagnostic Instructions•Perform the Diagnostic System Check - Vehicleprior to using thisdiagnostic procedure.
•Review Strategy Based Diagnosisfor an overview of thediagnostic approach.
• Diagnostic Procedure Instructionsprovides an overview ofeach diagnostic category.
DTC DescriptorDTC P0455
Evaporative Emission (EVAP) System Large Leak
The engine control module (ECM) tests the evaporativeemission (EVAP) system for a large leak. The ECM monitors the fueltank pressure (FTP) sensor signal to determine the EVAP systemvacuum level. When the conditions for running are met, the ECMcommands the EVAP canister purge solenoid valve OPEN and the EVAPvent solenoid valve CLOSED . This allows engine vacuum to enter theEVAP system. At a calibrated time, or vacuum level, the ECMcommands the EVAP canister purge solenoid valve closed, sealing thesystem, and monitors the FTP sensor input in order to determine theEVAP system vacuum level. The following table illustrates therelationship between the ON and OFF states, and the OPEN or CLOSEDstates of the EVAP canister purge and vent solenoid valves.
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 between10–18 volts.
•The barometric pressure (BARO) is more than75 kPa.
•The fuel level is between15–85 percent.
•The start-up engine coolant temperature (ECT) is between4–30°C (39–86°F).
•The start-up intake air temperature (IAT) is between4–30°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 within10 minutes of start-up.
Conditions for Setting the DTC
The EVAP system is not able to achieve or maintain vacuum forup 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 maycause this DTC to set.
•To help locate intermittent leaks, use the J 41413-200 Evaporative EmissionsSystem Tester (EEST) to introduce smoke into the EVAP system. Moveall EVAP components while observing smoke with the GE-41413-SPT High Intensity WhiteLight. Introducing smoke in 15-second intervals willallow less pressure into the EVAP system. When the system is lesspressurized, the smoke will sometimes escape in a more condensedmanner.
•To improve the visibility of the smoke exiting the EVAPsystem, observe the suspected leak area from different angles withthe GE-41413-SPT.
Reference InformationSchematic Reference • Engine Controls Schematics
• Evaporative Emissions Hose Routing Diagram
Connector End View Reference
Component Connector End 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
Control Module Referencesfor scan toolinformation
Special Tools • CH-48096 EVAP Service AccessPort Tool
• GE-41415-50 Fuel Tank CapAdapter
• J 41413-200(J 41413-100) Evaporative Emission SystemTester (EEST)
• J 41413-300 EVAP Cap and PlugKit
• J-41413-311 EVAP Plug
• J 41413-VLV EVAP Service PortVent Fitting
• GE-41413-SPT High Intensity WhiteLight
•Larger volume fuel tanks and/or those with lower fuel levelsmay require several minutes for the floating indicator tostabilize.
•Refer to the J 41413-200 operation manual fordetailed instructions.
1. Connect the J 41413-200 to the vehicle EVAPservice port. For vehicles without a service port, disconnect thepurge tube at the quick connector on the EVAP canister side of thepurge solenoid valve and install the CH-48096.
2. Seal the EVAP system and use the flow meter on the J 41413-200, calibrated to0.51 mm (0.02 in) to determine that there isno leak in the EVAP system.
⇒ If a leak is detected, use the J 41413-200 to apply smoke to theEVAP system at the service port until the leak is located.
3. To test for a restriction, connect the J 41413-200 nitrogen/smoke hoseto the J-41413-311 brass cone adapter.Disconnect the hose at the fuel cap end of the GE-41415-50. Connect the J-41413-311 to the disconnectedhose on the GE-41415-50. Install the GE-41415-50 filler neck end onlyto the vehicle.
4. Allow the engine to idle.
5. Use the Purge/Seal function to seal the system with a scantool.
6. Command the EVAP canister purge solenoid valve to30 percent.
7. The vacuum/pressure gauge on the J 41413-200 and the FTP parameteron the scan tool should both show vacuum.
⇒ If the vacuum/pressure gauge shows vacuum but the FTPparameter does not show vacuum, replace the FTP sensor.
⇒ If neither the FTP parameter nor the vacuum/pressure gaugeshows vacuum, repair the restriction in the purge path.
8. Verify that the vacuum increases to the abort limit on thescan tool or more than 3.2 volts, and the value isclosely similar between the scan tool and the vacuum/pressure gaugeon the J 41413-200.
⇒ If the values are not similar or the voltage did not reach3.2 volts, replace the FTP sensor.
Perform the Diagnostic Repair Verificationafter completing thediagnostic procedure.
• Fuel Tank Pressure Sensor Replacement
• Control Module Referencesfor ECM replacement, setup,and programming