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 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, P0121, P0122, P0123, P0222, P0223, P0128, P0443, P0449, P0452, P0453, P0454, P0601, P0602, P0606, P0722, P0723 are not set. |
• | The ignition voltage is between 10-18 volts. |
• | The barometric pressure (BARO) is more than 74 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 less than 30°C (86°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 before purge has reached a calibrated volume.
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
to introduce smoke into the EVAP system. Move all EVAP components while observing smoke 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. |
• | 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
. |
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 |
• | J 41413-200
Evaporative Emission System Tester (EEST) |
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. |
- Disconnect the purge tube at the quick connector on the EVAP canister side of the purge solenoid valve and install the
CH-48096
. Connect the
J 41413-200
to the
CH-48096
.
- Use a scan tool to seal the system and 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.
⇒ | 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. |
- Connect the
J 41413-200
nitrogen/smoke hose to 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 disconnected hose on the
GE-41415-50
. Install the
GE-41415-50
filler neck end only to the 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
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
.
⇒ | 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.