DTC P0457: Evaporative Emission System Leak Detected (Fuel Cap Loose/Off)
WARNING: This page does not describe the selected car, but rather 33 other vehicles, including the 2010 Mercury Mountaineer, 2010 Mercury Milan, 2010 Mercury Mariner, 2010 Mercury Grand Marquis, and 2010 Lincoln Town Car. However, it is still accessible from the selected car via links, so may be relevant.
DTC P0457: EVAPORATIVE EMISSION SYSTEM LEAK DETECTED (FUEL CAP LOOSE/OFF)
| Description: | The powertrain control module (PCM) continuously monitors the fuel level and retains the last updated value prior to the ignition switch being placed in the OFF position. After the ignition switch is placed in the ON position a new fuel level is taken and compared to the level recorded at ignition off. If the fuel level has increased, a flag is set in the PCM indicating the vehicle was refueled. If the evaporative emission (EVAP) monitor detects a gross leak while the refueling flag is set, a loose fuel filler cap or an incorrectly sealed fuel tank filler pipe (if equipped) is suspected and the DTC is set. On most vehicles when the DTC sets, either the check fuel cap indicator illuminates or a message on the instrument cluster displays to instruct the driver to check the fuel cap or capless fuel tank filler pipe (if equipped). | ||
| Possible Causes: |
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| Diagnostic Aids: | Check for a missing fuel filler cap or the integrity of the cap. Verify the capless fuel tank filler pipe is sealed correctly (if equipped). If OK, clear the continuous memory DTCs and test the system for correct operation. | ||
| Application | Key On Engine Off | Key On Engine Running | Continuous Memory |
| All | - | - | GO to PINPOINT TEST HX . |