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.
P0442-EVAP SYSTEM MEDIUM LEAK DIAGNOSTIC TEST REFERENCE
| TEST | ACTION | APPLICABILITY |
|---|---|---|
| 1 | Start by reading PCM DTC(s) and record the related Freeze Frame data in any DTC(s) are present. Check the vehicle repair history. If the vehicle has a repair history that pertains to the customer's current complaint, review the repair. Inspect the vehicle for any aftermarket accessories that may have been installed incorrectly. Check for any service bulletin(s) related to the customer's complaint or DTC(s). If a service bulletin applies, follow the instructions per service bulletin. Did the service bulletin repair the customer's complaint? Yes --> Testing Complete. Perform POWERTRAIN VERIFICATION TEST VER - 6 . No --> Go To 2 |
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| 2 | Check for any related TSBs before continuing.
NOTE:
Since a hot vehicle can conceal a leak, it is best to perform this test at room temperature.
NOTE:
A loose gas cap could have caused this DTC to set. Make sure gas cap is tight and in good condition. Make sure the gas cap meets OEM specifications. 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 3 No --> Refer to the INTERMITTENT CONDITION SYMPTOM . Perform POWERTRAIN VERIFICATION TEST VER - 6 . |
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| 3 | Perform a visual and physical inspection of the entire Evaporative Emission system. Check for the follow conditions:
Were any of the above conditions found? Yes --> Repair as necessary. 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 lit 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 flow meter is now calibrated 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 #8404-ADP service adaptor in the filter line. Connect the Air supply hose from the EELD to the service port (if equipped) or #8404-ADP in the filter line. 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 --> Refer to the FREEZE FRAME data recorded in Step 1. If the data indicates that the vehicle was in motion when the DTC was set, verify that all hoses are properly connected. Test Complete. Perform POWERTRAIN VERIFICATION TEST VER - 6 . |
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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 or the #8404-ADP adapter.Connect the SMOKE supply tip (black hose) to the service port (if equipped) or to the #8404-ADP adapter.Set the smoke/air control switch to SMOKE.
NOTE:
The flow meter indicator ball will not move at this point. 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 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:
The EVAP System is divided into three zones. Possible leaking areas can be from any of the three Zones. ZONE 1.
NOTE:
Carefully inspect the vent side of the EVAP Canister. Due to the filtering system in the canister the smoke or dye may or may not be visible. Introducing smoke into the filtered side of the canister may assist in locating the leak. Was a leak found?Yes --> Go To 6No --> Go To 7 |
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| 6 | Remove the SMOKE supply tip (black hose) from the Service port (if equipped) or to the #8404-ADP adapter. Install gas cap adapter, Miller Tool #8382 (1/4 turn cap) or #6922 (screw cap) and #8399 (secondary seal depressor) and repeat test 5. Was a leak at the gas cap adapter? Yes --> Replace the fuel filler tube assembly. Perform POWERTRAIN VERIFICATION TEST VER - 6 . No --> Replace the gas cap. Perform POWERTRAIN VERIFICATION TEST VER - 6 . |
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| 7 | To continue testing you will need Miller Tool #8404 Evaporative Emission Leak Detector (EELD).
WARNING:
Keep lit 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. Connect the red power lead of EELD to the battery positive terminal and the black ground lead to battery negative terminal. Disconnect the vacuum hoses at he Evap Purge Solenoid. Connect the SMOKE supply tip (black hose) to the service port (if equipped) or to the #8404-ADP adapter. Set the smoke/air control switch to SMOKE. Press the remote smoke/air start button.
NOTE:
Below is an optional method of checking the purge valve for leaks if the EELD is unavailable. Turn the ignition off. Disconnect the vacuum supply hoses from the EVAP Purge Solenoid. Using a hand vacuum pump, apply 10 in Hg to the "CAN" side of the EVAP Purge Solenoid. Observe the vacuum gauge for at least 15 seconds. With the DRBIII®, actuate the Evap Purge Solenoid.
NOTE:
If the Evap Purge Solenoid does not hold a vacuum, it will need to be replaced. Is smoke visible from the Evap Purge Solenoid? Yes --> Replace the Evap Purge Solenoid. Perform POWERTRAIN VERIFICATION TEST VER - 6 . No --> Replace the NVLD Assembly. Perform POWERTRAIN VERIFICATION TEST VER - 6 . |
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