P0455
P0455 - EVAP SYSTEM LARGE LEAK
When Monitored and Set Condition
- When Monitored: Engine Running. Cold start test. Fuel Level greater than 12%, ambient temperature between 4°C and 32°C (39°F and 89°F), closed loop system operation. Test runs when small leak test is maturing.
- Set Condition: The PCM activates the EVAP Purge Solenoid to pull the EVAP system into a vacuum. The PCM turns the EVAP Purge solenoid off to seal the EVAP system. If the fuel tank pressure sensor reads normal operating pressure sooner than expected, a Large Leak error is detected.
For a complete Powertrain Control Module Circuit Diagram, Schematics and Diagrams.
Diagnostic Test
1. PRE-DIAGNOSTIC CHECK OUT
NOTE: Always perform diagnostics with a fully charged battery.
NOTE: Check connectors - Clean/repair as necessary. Poor pin to terminal connections can set DTCs.
NOTE: Check for applicable TSBs related to the problem.
Turn the ignition on.
With the scan tool, read PCM DTCs.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors. Repair as necessary.
Perform this procedure prior to symptom diagnosis.
Continue
- Go To 2
2. CHECK FOR CURRENT DTC
NOTE: Since a hot vehicle can conceal a leak, it is best to perform this test at room temperature.
NOTE: A loose fuel filler cap could have caused this DTC to set. Make sure fuel filler cap is tight and in good condition. Ensure the fuel filler cap meets OEM specifications.
NOTE: If the PCM detects and stores a DTC, the PCM also stores the engine/vehicle operating conditions under which the DTC was set. Some of these conditions are displayed on the scan tool at the same time the DTC is displayed.
NOTE: Before erasing stored DTCs, record these conditions. Attempting to duplicate these conditions may assist when checking for an active DTC.
Turn the ignition on.
With the scan tool, erase PCM DTCs.
NOTE: It maybe necessary to road test the vehicle for this DTC to set.
With the scan tool, read PCM DTCs.
Did this DTC set again?
Yes
- Go To 3
No
- Go To 8
3. VISUAL AND PHYSICAL INSPECTION
Turn the ignition off.
Perform a visual and physical inspection of the entire Evaporative Emission system.
Check for the follow conditions:
- Holes or cracks
- Loose seal points
- Evidence of damaged components
- Incorrect routing of hoses and tubes
- Fuel Filler Cap gasket seal
Were any of the above conditions found?
Yes
- Repair as necessary.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test
No
- Go To 4
4. VERIFY EVAPORATIVE EMISSION LEAK
WARNING: KEEP LIGHTED CIGARETTES, SPARKS, FLAMES, AND OTHER IGNITION SOURCES AWAY FROM THE TEST AREA TO PREVENT THE IGNITION OF EXPLOSIVE GASES. KEEP THE TEST AREA WELL VENTILATED.
NOTE: The fuel tank should have between 20% and 80% of fuel tank capacity to properly test the Evap system.
To continue testing you will need Special Tool #8404 Evaporative Emission Leak Detector (EELD).
Connect the red power lead of the EELD to the battery positive terminal and the black ground lead to battery negative terminal.
Block the vent hose of the EVAP Canister.
Connect shop air to the EELD.
Set the smoke/air control switch to AIR.
Insert the tester's AIR supply tip (clear hose) into the appropriate calibration orifice on the tester's control panel (based on DTC leak size).
Press the remote smoke/air start button.
Position the red flag on the air flow meter so it is aligned with the indicator ball.
When the calibration is complete, release the remote button. The EELD is now calibrated the flow meter in liters per minute to the size leak indicated by the DTC set in the PCM.
Install the service port adapter (Special Tool #8404-14) on the vehicle's service port.
Connect the Air supply hose from the EELD to the service port.
Press the remote button to activate AIR flow.
NOTE: Larger volume fuel tanks, lower fuel levels or if the vehicle is equipped with a Flow Management Valve may indicate high flow and will require 4 to 5 minutes to fill.
Compare the flow meter indicator ball reading to the red flag.
ABOVE the red flag indicates a leak present.
BELOW the red flag indicates a sealed system.
Is the indicator ball above the red flag?
Yes
- Go To 5
No
- Go To 8
5. EVAPORATIVE EMISSION LEAK DETECTION
NOTE: A thorough visual inspection of the Evap system hoses, tubes, and connections may save time in your diagnosis. Look for any physical damage or signs of wetness at connections. The strong smell of fuel vapors may aid diagnosis also.
Remove the Air supply hose from the vehicle's service port.
Connect the SMOKE supply tip (black hose) to the vehicle's service port.
Set the smoke/air control switch to SMOKE.
NOTE: The flow meter indicator ball will not move in the smoke mode.
Press the remote smoke/air start button.
NOTE: Ensure that smoke has filled the EVAP system by continuing to press the remote smoke/air start button, remove the vehicle's fuel filler cap and wait for the smoke to exit. Once smoke is indicated, reinstall the fuel filler cap.
NOTE: For optimal performance, introduce smoke into the system for an additional 60 seconds; continue introducing smoke at 15 second intervals as necessary.
While still holding the remote smoke/air start button, use the white light (Special Tool #8404-CLL) to follow the EVAP system path and look for the source of the leak indicated by exiting smoke.
If a leak is concealed from view (i.e., top of fuel tank), release the remote smoke/air start button and use the ultraviolet (UV) black light #8404-UVL and the yellow goggles #8404-20 to look for residual traces of dye that are left behind by the smoke.
The exiting smoke deposits a residual fluid that is either bright green or bright yellow in color when viewed with a UV light.
NOTE: Carefully inspect the vent side of the EVAP Canister. Due to the filtering system in the canister the smoke may not be as thick. Introducing smoke into the filtered side of the canister may assist in locating the leak.
Was a leak found?
Yes
- Repair or replace the leaking component as necessary.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test
No
- Go To 6
6. EVAP PURGE SOLENOID OPERATION
NOTE: After disconnecting the Evap Purge Solenoid vapor hose connections, inspect the lines and solenoid for any signs of contamination from the EVAP Canister. This may indicate a faulty rollover valve. Replace/repair as necessary.
With the ignition off.
Disconnect the vacuum hoses at the Evap Purge Solenoid.
Using a hand vacuum pump, apply 330 mm Hg (10 in. Hg) to the canister side of the EVAP Purge Solenoid.
NOTE: Monitor the vacuum gauge for at least 15 seconds.
Does the EVAP Purge Solenoid hold vacuum?
Yes
- Go To 7
No
- Replace the Evap Purge Solenoid. EVAP Purge Solenoid - Removal.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test
7. FUEL TANK PRESSURE SENSOR OPERATION
NOTE: The fuel level must be below 85%, or the Tank Vent/Rollover Valves and the Fuel Tank Overfill Check Valve will seal the tank.
Turn the ignition off.
Install the fuel filler cap adapter. Attach the fuel filler cap to the adapter.
Connect a hand-held vacuum pump to the fuel filler cap adapter.
Slowly apply vacuum while monitoring the fuel tank pressure sensor on the scan tool. Do not exceed 66 mm Hg (2 in. Hg) while performing this step.
NOTE: The fuel tank pressure sensor reads normally -1 hPa (-0.0145 psi). When the vacuum is applied and 330 mm Hg (1 in. Hg) is reached, the fuel tank pressure sensor should be approximately -5 hPa (-0.0725 psi). Once the vacuum has been released, the fuel tank pressure sensor should return to a normal reading.
Did the fuel tank pressure sensor operate as described above?
Yes
- Go To 8
No
- Replace the Fuel Level Sending Unit/Pressure Sensor. Removal.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test
8. INTERMITTENT CONDITION
WARNING: WHEN THE ENGINE IS OPERATING, DO NOT STAND IN A DIRECT LINE WITH THE FAN. DO NOT PUT YOUR HANDS NEAR THE PULLEYS, BELTS OR FAN. DO NOT WEAR LOOSE CLOTHING.
Review the scan tool Freeze Frame information. If possible, try to duplicate the conditions under which the DTC was set.
Search for any Technical Service Bulletins (TSB) that may apply.
NOTE: A loose fuel filler cap could have caused this DTC to set. Make sure fuel filler cap is tight and in good condition. Ensure the fuel filler cap meets OEM specifications.
Perform a visual and physical inspection of the entire Evaporative Emission system.
Check for the following conditions:
- Holes or cracks
- Loose seal points
- Evidence of damaged components
- Incorrect routing of hoses and tubes
- Fuel filler cap gasket seal
Were any of the above conditions found?
Yes
- Repair as necessary.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test
No
- The condition that caused this symptom is currently not present. Inspect the related wiring harness for a possible intermittent condition.