Diagnostic Instructions
DTC Descriptor
DTC P0455: Evaporative Emission (EVAP) System Large Leak
Circuit/System Description
The engine control module (ECM) tests the evaporative emission (EVAP) system for a large leak or a restriction in the purge path. When the conditions for running are met, the ECM commands the EVAP canister purge solenoid valve OPEN and the EVAP vent solenoid
valve CLOSED allowing engine vacuum to enter the EVAP system. The ECM monitors the fuel tank pressure (FTP) sensor signal to verify that the EVAP system is able to reach a predetermined vacuum level within a set amount of time.
Conditions for Running the DTC
• | DTCs P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0122, P0123, P0128, P0222, P0223, P0443, P0449, P0451, P0452, P0453, P0454, P0502, P0503, P0601, P0602, P0606, P0641 are not set. |
• | The ignition voltage is between 11-18 volts. |
• | The barometric pressure (BARO) is more than 74 kPa. |
• | The fuel level is between 15-85 percent. |
• | The start-up intake air temperature (IAT) is between 4-30°C (39-86°F). |
• | The start-up engine coolant temperature (ECT) is less than 35°C (95°F). |
• | The start-up ECT and IAT are within 8°C (14.4°F) of each other. |
• | DTC P0455 runs once per cold start within 17 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
• | Inspect for a loose, missing, incorrect, or damaged fuel fill cap. |
• | Verify that the fuel filler neck sealing surface is not distorted or damaged. |
• | To help locate intermittent leaks, use the
J 41413-200 (J 41413-100) EEST
to introduce smoke into the EVAP system. Move all EVAP components while observing smoke
with a high intensity white light. |
• | 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. |
• | A condition may exist where a leak in the EVAP system only exists under a vacuum condition. By using the scan tool Purge/Seal function to create a vacuum, seal the system and observe the FTP parameter for the vacuum decay, this type of leak may be
detected. |
• | If a small leak is difficult to find, it may be necessary to remove the EVAP components and leak test them one at a time using the adapters in the
J 41413-300 Kit
. |
Reference Information
Schematic Reference
Connector End View Reference
Component Connector End Views
Description and Operation Reference
Evaporative Emission Control System Description
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Special Tools
• | CH 48096 EVAP Service Access Port Tool |
• | GE 41415-50 Fuel Tank Cap Adapter |
• | J 41413-200 (J 41413-100) Evaporative Emission System Tester (EEST) |
• | J 41413-300 EVAP Cap and Plug Kit |
• | J 41413-VLV EVAP Port Vent Fitting Tool |
Circuit/System Testing
Note:
• | Larger volume fuel tanks and/or those with lower fuel levels may require several minutes for the floating indicator to stabilize. |
- Disconnect the purge tube at the quick connector on the EVAP canister side of the purge solenoid valve and install the
CH 48096 Port Tool
. Connect the
J 41413-200
(J 41413-100) EEST
to the
CH 48096 Port Tool
.
- Use a scan tool to seal the system and use the flow meter on the
J 41413-200 (J 41413-100) EEST
, calibrated to 0.51 mm (0.020 in) to determine
that there is no leak in the EVAP system.
⇒ | If a leak is detected use the
J 41413-200 (J 41413-100) EEST
to apply smoke to the EVAP system at the service port or the filler neck until the leak is located. |
- Connect the
J 41413-200 (J 41413-100) EEST
nitrogen/smoke hose to the
J 41413-311 EVAP Plug
brass cone adapter. Disconnect the hose at the fuel cap end of the
GE 41415-50 Adapter
. Connect the
J 41413-311 EVAP Plug
to the disconnected hose on the
GE 41415-50 Adapter
. Install the
GE 41415-50 Adapter
filler neck end only tot he vehicle.
- Start the engine.
- Allow the engine to idle.
- Use the Purge/Seal function to seal the system with a scan tool.
- Command the EVAP canister purge solenoid valve to 20 percent.
- The vacuum/pressure gage on the
J 41413-200 (J 41413-100) EEST
and the FTP parameter on the scan tool should both show vacuum.
⇒ | If the vacuum/pressure gage shows vacuum but the FTP parameter does not show vacuum, replace the FTP sensor. |
⇒ | If neither the FTP parameter nor the vacuum/pressure gage shows vacuum, repair the restriction in the purge path. |
- Verify that the vacuum increases to the abort limit on the scan tool or more than 3.2 volts, and the value is similar between the scan tool and the vacuum/pressure gage on the
J 41413-200 (J 41413-100) EEST
.
⇒ | If the values are not similar or the voltage did not reach 3.2 volts, replace the FTP sensor. |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.