Diagnostic Instructions
DTC Descriptor
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.
FTP Sensor Signal Voltage
| Fuel Tank Pressure
|
High, Approximately 1.5 Volts or More
| Negative Pressure/Vacuum
|
Low, Approximately 1.5 Volts or Less
| Positive Pressure
|
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.
Control Module Command
| EVAP Canister Purge Valve
| EVAP Canister Vent Valve
|
ON
| Open
| Closed
|
OFF
| Closed
| Open
|
Conditions for Running the DTC
• | Before the engine control module (ECM) can report DTC P0455 or DTC P0497 failed, DTCs P0443, P0450, P0451, P0452, P0453, P0458, and P0459 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 volts. |
• | The engine run time is greater than 10 minutes or the fuel trim is stable. |
• | The fuel tank pressure (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 barometric pressure (BARO) is greater than 68 kPa. |
• | The fuel level is between 11-88 percent. |
• | 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 seconds |
• | 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 seconds or for a cumulative of 30 seconds. |
Action Taken When the DTC Sets
DTCs P0455 and P0497 are Type A/B DTCs.
Conditions for Clearing the DTC
DTCs P0455 and P0497 are Type A/B DTCs.
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
Evaporative Emissions System Tester (EEST) to introduce smoke into the EVAP system. Move all EVAP components while observing smoke with the
J 41413-SPT
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 the
J 41413-SPT
. |
• | 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
Connector End View Reference
Component Connector End Views
Description and Operation
Evaporative Emission Control System Description
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Special Tools
• | J 41413-200
Evaporative Emissions System Tester (EEST) |
• |
CH-48096
EVAP Service Port Access Tool |
Circuit/System Verification
- 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 EVAP canister purge solenoid valve |
• | Disconnected, incorrectly routed, kinked, or damaged EVAP pipes and hoses |
• | A damaged EVAP vent valve or EVAP canister |
⇒ | If you find any of the above conditions, repair as necessary. |
Note: Refer to the
J 41413-200
operation manual for detailed instructions.
- Remove the fuel fill cap. Connect the
GE-41415-50
to the fuel tank filler neck. Connect the
J 41413-200
to the
GE-41415-50
.
- Calibrate the
J 41413-200
Flow Meter to the correct leak orifice for the vehicle.
- Command the EVAP vent solenoid closed with a scan tool.
Note: Larger volume fuel tanks and/or those with lower fuel levels may require several minutes for the floating indicator to stabilize.
- Activate the
J 41413-200
and compare the flow meter's stable floating indicator position to the red flag. The floating indicator should be below 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. |
- 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. |
- Connect the
GE-41415-50
to the fuel tank filler neck. Connect the
J 41413-200
to the
GE-41415-50
.
- Connect the
CH-48096
between the EVAP purge solenoid and the EVAP purge pipe.
- Turn the nitrogen/smoke valve on the control panel to SMOKE.
- Command the EVAP vent solenoid closed with a scan tool.
- Use the remote switch to introduce smoke into the EVAP system.
- Use the
J 41413-VLV
to open the EVAP service port. Once smoke is observed, remove the
J 41413-VLV
.
Note: Introduce smoke at 15 second intervals while testing the system.
- Verify that smoke is not exiting the entire EVAP system with the
J 41413-SPT
.
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. |
- Remove the
J 41413-200
nitrogen supply hose from the
GE-41415-50
, and remove the
GE-41415-50
from the fuller neck.
- Install the fuel fill cap.
- Connect the
J 41413-200
nitrogen/smoke supply hose to the EVAP service port of the
CH-48096
.
- Command the EVAP vent solenoid closed with a scan tool.
- 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.
- Verify that smoke is not exiting the entire EVAP system with the
J 41413-SPT
.
⇒ | If smoke is observed, repair the condition as necessary. |
- Verify the individual EVAP system components for a leak using the
J 41413-300
.
⇒ | If a condition is found replace the affected component. |
Blockage/Restriction Testing
- Connect the
GE-41415-50
to the fuel tank filler neck. Connect the
J 41413-200
to the
GE-41415-50
.
- Seal the EVAP system with the scan tool EVAP Purge/Seal function.
- Pressurize the EVAP system with nitrogen to 9.33 mm/Hg 5 in/H20. Compare the scan tool Fuel Tank Pressure Sensor parameter to the
J 41413-200
pressure/vacuum gage. The FTP sensor
parameter should be within 1.86 mm/Hg (1 in/H2O) of the pressure/vacuum gage.
⇒ | If not within the specified range, replace the FTP sensor. |
- Increase the EVAP purge solenoid to 100 %. The FTP sensor pressure should drop to less than 1.86 mm/Hg (1 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 less than the specified value when a pipe is disconnected, test for
a blockage or restriction in one of the following EVAP pipe/hoses: |
4.1. | EVAP purge vacuum source from the EVAP purge solenoid |
4.2. | EVAP purge pipe from the EVAP purge solenoid |
4.3. | EVAP purge pipe at the EVAP canister |
4.4. | EVAP vapor pipe at the EVAP canister |
- If you cannot locate a condition with the EVAP system, refer to Diagnostic Aids for additional information.
Component Testing
- Seal the EVAP system with the scan tool EVAP Purge/Seal function.
- Pressurize the EVAP system to 9.33 mm/Hg (5 in/H20).
- Compare the scan tool Fuel Tank Pressure sensor parameter to the
J 41413-200
pressure/vacuum gage. The scan tool FTP sensor parameter should be within 1.86 mm/Hg (1 in/H20) of the
pressure/vacuum gage.
- Command the EVAP vent valve open with a scan tool. The scan tool Fuel Tank Pressure parameter should be approximately 0 mm/Hg (0 in/H20).
⇒ | If not within the specified range, replace the FTP sensor. |
Repair Instructions
Repair Verification
- Turn the nitrogen/smoke valve to nitrogen.
- Command the EVAP vent valve closed with a scan tool.
- Use the remote switch to activate the
J 41413-200
.
- Use the remote switch to introduce nitrogen and fill the EVAP system until the floating indicator stabilizes.
- Verify the flow meter's stable floating indicator position is at or below the red flag.
- Remove the
CH-48096
, and connect the purge line to the EVAP purge solenoid.
- Clear the DTCs with a scan tool.