Diagnostic Procedure
WARNING: This page is about a different car, the 2005 Jeep Liberty. However, it is still accessible from the selected car via links, so may be relevant.
P0457-LOOSE FUEL CAP DIAGNOSTIC TEST REFERENCE
| TEST | ACTION | APPLICABILITY |
|---|---|---|
| 1 |
NOTE:
After the PCM has determined the leak test inconclusive and sees an increase in fuel level, the PCM will request the GAS CAP indicator on to inform the customer that the gas fill cap is loose or off. Ignition on, engine not running.With the DRBIII®, read DTCs and record the related Freeze Frame data.Is the Good Trip Counter displayed and equal to zero?Yes --> Go To 2No --> Refer to the INTERMITTENT CONDITION SYMPTOM .Perform POWERTRAIN VERIFICATION TEST VER - 6 . |
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| 2 | Perform a visual and physical inspection of the Fuel Fill Cap and the fill tube. Check for the follow conditions:
Were any of the above conditions found? Yes --> Repair or replace the fuel fill cap as needed. Ensure proper fuel fill cap installation. Once the repair is complete continue to step 3. Perform POWERTRAIN VERIFICATION TEST VER - 6 . No --> Go To 3 |
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| 3 | With the DRBIII®, perform the NVLD Service Test. Did the NVLD Service Test pass? Yes --> Test Complete. Perform POWERTRAIN VERIFICATION TEST VER - 6 . No --> Go To 4 |
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| 4 | To continue testing you will need Miller Tool #8404 Evaporative Emission Leak Detector (EELD).
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. Connect the red power lead of the EELD to the battery positive terminal and the black ground lead to battery negative terminal.
NOTE:
See CHARTS AND GRAPH support material EELD Calibration Setup for an example. 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 #8404-14 on the vehicle's service port (if equipped) or install the #8404-ADP service adapter in the NVLD filter line. 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 |
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| 5 |
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. To continue testing, you will need Miller Tool #8404 Evaporative Emissions Leak Detector (EELD).Remove the Air supply hose from the service port.Connect the SMOKE supply tip (black hose) to the 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:
Make sure that smoke has filled the EVAP system by continuing to press the remote smoke/air start button, remove the vehicle fuel cap, and wait for the smoke to exit. Once smoke is indicated reinstall the fuel 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 (#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 is 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 - 6 .No --> Go To 6 |
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| 6 |
NOTE:
After disconnecting the Evap Purge Solenoid vacuum connections, inspect the lines and solenoid for any signs of contamination from the EVAP Canister. This may indicate a faulty vent valve. Replace/repair as necessary. Turn the ignition off.Disconnect the vacuum hoses at the Evap Purge Solenoid.Using a hand vacuum pump, apply 10 in Hg to the "CAN" 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 7No --> Replace the Evap Purge Solenoid.Perform POWERTRAIN VERIFICATION TEST VER - 6 . |
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| 7 | Reconnect all vacuum hoses. Start the engine. Allow the engine to idle. Using the DRBIII®, perform the NVLD FORCED MONITOR TEST. Monitor the NVLD Switch. As the test runs, the NVLD Switch should go from an OPEN state to CLOSED. After the vacuum is released form the EVAP system the Switch state will return to OPEN. Did the NVLD Switch operate as described above? Yes --> Go To 8 No --> Replace the NVLD Assembly. Perform POWERTRAIN VERIFICATION TEST VER - 6 . |
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| 8 |
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 DRBIII® Freeze Frame information. If possible, try to duplicate the conditions under which the DTC was set.Refer to any Technical Service Bulletins (TSBs) that may apply.
NOTE:
Make Ensure the gas cap meets OEM specifications. Perform a visual and physical inspection of the entire Evaporative Emission system.Check for the following conditions:
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