P0455
DTC P0455 or P0497
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.
DTC Descriptors
DTC P0455
- Evaporative Emission (EVAP) System Large Leak Detected
DTC P0497
- Evaporative Emission (EVAP) System No Flow During Purge
Circuit/System Description
The control module tests the evaporative emission (EVAP) system for a large leak, or a stuck closed EVAP canister purge valve. 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, a DTC sets.
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 valves.
Conditions for Running the DTC
* Before the engine control module (ECM) can report DTC P0455 or DTC P0497 failed, DTCs P0446 and P0496 must run and pass.
* DTC P0100, P0101, P0102, P0103, P0111, P0112, P0113, P0116, P0117, P0118, P0119, P0443, P0446, P0449, P0450, P0451, P0452, P0453, P0458, P0459, P0496, P0498, P0499, P0560, P0562, P0563, P0700, P2122, P2123, P2127, P2128, P2138, P2227, P2228, or P2229 is not set.
* The ignition voltage is between 10-18 V.
* The engine run time is greater than 10 min or the fuel trim is stable.
* The FTP is between -18.7 and +9.8 mm Hg (-10.0 and +5.2 in. H2O).
* The Closed Loop fuel control is enabled.
* The engine is idling.
* The barometric pressure (BARO) is greater than 68 kPa.
* The fuel level is between 11-88 %.
* The ambient air temperature (IAT) is between 2-32°C (36-90°F).
* The engine coolant temperature (ECT) is within 10°C (18°F) of the ambient air temperature at engine start.
* The vehicle speed sensor (VSS) is less than 3 km/h (2 mph).
* The above conditions are met for greater than 30 s.
* DTC P0455 or DTC P0497 will attempt to run up to 10 times or until the test completes successfully once per ignition cycle.
Conditions for Setting the DTC
* The ECM detects the EVAP system is not able to achieve or maintain vacuum during the diagnostic test.
* The condition exists for greater than 4 s or for a cumulative of 30 s.
Action Taken When the DTC Sets
* DTC P0455 is a Type B DTC.
* DTC P0497 is a Type A DTC.
Conditions for Clearing the DTC
* DTC P0455 is a Type B DTC.
* DTC P0497 is a Type A DTC.
Diagnostic Aids
* A loose, missing, or damaged fuel fill cap can cause this DTC to set.
* A stuck closed, blocked, or restricted EVAP canister purge solenoid valve, can cause this DTC to set.
* A blockage or restriction in the EVAP canister purge solenoid valve vacuum supply hose, EVAP canister purge solenoid valve purge pipe, EVAP canister, or vapor pipe, can cause this DTC to set.
* A temporary blockage in the EVAP canister purge solenoid valve, purge pipe or EVAP canister could cause an intermittent condition. Inspect and repair any restriction in the EVAP system.
* To help locate intermittent leaks, use the J 41413-200 - EEST to introduce smoke into the EVAP system. Move all EVAP components while observing smoke with the J 41413-SPT - White Light. Introducing smoke in 15 s 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 the J 41413-SPT - White Light.
* Observe the Freeze Frame/Failure Records vehicle mileage since the diagnostic test last failed may help determine how often the condition occurs that caused the DTC to set. This may assist in diagnosing the condition.
Reference Information
Schematic Reference
Engine Controls Schematics ([1][2]Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
Description and Operation
Evaporative Emission Control System Description (Evaporative Emission Control System Description)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Special Tools
* CH-48096 - EVAP Service Port Access Tool
* J 41413-200 - Evaporative Emissions System Tester (EEST)
* J 41413-300 - EVAP Cap and Plug Kit
* J 41413-SPT - High Intensity White Light
* J 41413-VLV - EVAP Port Vent Fitting Tool
* J-41415-30 - Fuel Tank Adapter
* For equivalent regional tools, refer to Special Tools (Tools and Equipment).
Circuit/System Verification
1. Verify the following conditions do not exist in the EVAP system:
* Loose, incorrect, missing, or damaged fuel fill cap
* Loose, missing, or damaged service port schrader valve, if equipped
* A damaged Q12 EVAP canister purge solenoid valve
* Disconnected, incorrectly routed, kinked, or damaged EVAP pipes and hoses
* A damaged Q13 EVAP vent solenoid valve or EVAP canister
• If you find any of the above conditions, repair as necessary.
Note: Refer to the J 41413-200 - Evaporative Emissions System Tester (EEST) operation manual for detailed instructions.
2. Remove the fuel fill cap. Connect the J-41415-30 - Adapter to the fuel tank filler neck. Connect the J 41413-200 - EEST to the J-41415-30 - Adapter.
3. Calibrate the J 41413-200 - EEST Flow Meter to 0.51 mm (0.020 in).
4. Command the EVAP vent solenoid valve closed with a scan tool.
Note: Larger volume fuel tanks and/or those with lower fuel levels may require several min for the floating indicator to stabilize.
5. Activate the J 41413-200 - EEST and compare the flow meter's stable floating indicator position to the red flag. The floating indicator should be level with the red flag.
• If the floating indicator is above the red flag, test for a leak in the EVAP system.
• If the floating indicator is below the red flag, test for a blockage or restriction in the EVAP system.
6. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
Leak Testing
Note:
* You must start with the Circuit/System Verification before proceeding with Circuit/System Testing.
* 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. Connect the J-41415-30 - Adapter to the fuel tank filler neck. Connect the J 41413-200 - EEST to the J-41415-30 - Adapter.
2. Connect the CH-48096 - Access Tool between the Q12 EVAP purge solenoid valve and the EVAP purge pipe.
3. Turn the nitrogen/smoke valve on the control panel to SMOKE.
4. Command the Q13 EVAP vent solenoid valve closed with a scan tool.
5. Use the remote switch to introduce smoke into the EVAP system.
6. Use the J 41413-VLV - Fitting Tool to open the EVAP service port. Once smoke is observed, remove the J 41413-VLV - Fitting Tool.
Note: Introduce smoke at 15 s intervals while testing the system.
7. Verify that smoke is not exiting the entire EVAP system with the J 41413-SPT - White Light.
Note: The fuel tank may need to be lowered to improve visibility of some of the EVAP system components.
• If smoke is observed, repair the condition as necessary.
8. Remove the J 41413-200 - EEST nitrogen supply hose from the J-41415-30 - Adapter , and remove the J-41415-30 - Adapter from the filler neck.
9. Install the fuel fill cap.
10. Connect the J 41413-200 - EEST nitrogen/smoke supply hose to the EVAP service port of the CH-48096 - Access Tool.
11. Command the Q13 EVAP vent solenoid valve closed with a scan tool.
12. Use the remote switch to introduce smoke into the EVAP system.
Note: The fuel tank may need to be lowered to improve visibility of some of the EVAP system components.
13. Verify that smoke is not exiting the entire EVAP system with the J 41413-SPT - White Light.
• If smoke is observed, repair the condition as necessary.
14. Verify individual EVAP system components do not leak using the J 41413-300 - Kit.
• If a condition is found replace the affected component.
Blockage/Restriction Testing
1. Connect the J-41415-30 - Adapter to the fuel tank filler neck. Connect the J 41413-200 - EEST to the J-41415-30 - Adapter.
2. Seal the EVAP system using the scan tool EVAP Purge/Seal function.
3. Pressurize the EVAP system with nitrogen to 9.33 mm/Hg (5 in/H2O). Compare the scan tool Fuel Tank Pressure Sensor parameter to the J 41413-200 - EEST pressure/vacuum gauge. Verify the scan tool FTP sensor parameter is within +/-0.9 mmHg (+/-0.5 in. H2O) of the pressure/vacuum gauge.
• If not within the specified range, replace the B150 FTP sensor.
4. Command the Q12 EVAP purge solenoid valve to 100 % with a scan tool. Verify the scan tool FTP sensor parameter is -0.9 to +0.9 mmHg (-0.5 to +0.5 in.H2O).
• If greater than the specified value, disconnect the EVAP pipes listed below one at a time while observing the scan tool FTP sensor parameter. If the FTP sensor parameter drops to within the specified range when a pipe is disconnected, repair the blockage or restriction in one of the following EVAP pipe/hoses:
* EVAP purge vacuum source from the Q12 EVAP purge solenoid valve
* EVAP purge pipe from the Q12 EVAP purge solenoid valve
* EVAP purge pipe at the EVAP canister
* EVAP vapor pipe at the EVAP canister
5. If a condition with the EVAP system cannot be located, refer to Diagnostic Aids for additional information.
Component Testing
1. Seal the EVAP system using the scan tool EVAP Purge/Seal function.
2. Pressurize the EVAP system to 9.33 mm/Hg (5 in/H2O).
3. Compare the scan tool Fuel Tank Pressure sensor parameter to the J 41413-200 - EEST pressure/vacuum gauge. Verify the scan tool FTP sensor parameter is within +/-0.9 mmHg (+/-0.5 in. H2O) of the pressure/vacuum gauge.
• If not within the specified range, replace the B150 FTP sensor.
4. Command the Q13 EVAP vent solenoid valve open with a scan tool. Verify the scan tool FTP sensor parameter is -0.9 to +0.9 mmHg (-0.5 to +0.5 in.H2O).
• If not within the specified range, replace the B150 FTP sensor.
Repair Instructions
* Fuel Tank Pressure Sensor Replacement (Service and Repair)
* Evaporative Emission Canister Purge Solenoid Valve Replacement (Service and Repair)
* Evaporative Emission Canister Vent Solenoid Valve Replacement (Service and Repair)
* Evaporative Emission Canister Replacement (Service and Repair)
Repair Verification
1. Turn the nitrogen/smoke valve to nitrogen.
2. Command the Q13 EVAP vent solenoid valve closed with a scan tool.
3. Use the remote switch to activate the J 41413-200 - EEST.
4. Use the remote switch to introduce nitrogen and fill the EVAP system until the floating indicator stabilizes.
5. Verify the flow meter's stable floating indicator position is at or below the red flag.
6. Remove the CH-48096 - Access Tool , and connect the purge hose/pipe to the EVAP purge solenoid valve.
7. Clear the DTCs with a scan tool.