EVAP Control System Leak Detected Fuel Filler Cap Loose/Off
Table of contents
P0457 MERCURY Possible Causes
- Missing fuel filler cap
- Incorrect fuel filler cap used
- Fuel filler cap remains open or fails to close
- Foreign matter caught in fuel filler cap
How do I fix code P0457 MERCURY?
Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.
Tech Notes
- There is a factory service bulletin for the following Mercury vehicles:
- 1997-1999 Mercury Tracer
- 1997-2000 Mercury Mystique
- 1997-2003 Mercury Grand Marquis
- 1997-2003 Mercury Sable
- 1999-2002 Mercury Cougar
- 1997-2003 Mercury Mountaineer
- Mercury Factory Service Bulletin OBDII Code P0457
Cost of diagnosing the P0457 MERCURY code
The cost of diagnosing the P0457 MERCURY code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
- Possible a noticeable fuel odor caused by the release of fuel vapors
P0457 MERCURY Description
Vehicles that meet enhanced evaporative requirements utilize a vacuum-based evaporative system integrity check. The EVAP system integrity check uses a Fuel Tank Pressure Transducer (FTPT), a Canister Vent Solenoid (CVS) and Fuel Level Input (FLI) along with the Vapor Management Valve (VMV) or Electric Vapor Management Valve (EVMV) to find 0.040” diameter or larger EVAP system leaks. Federal vehicles can utilize a 0.040″ leak check rather than the 0.020″ leak check required for California vehicles.
The Diagnostic Trouble Code (DTC) will set when the EVAP control system has a very large leak such as the fuel filler cap fell off, the EVAP control system does not operate properly.