P0451 Mercury Code - Evaporative Emission Control System Pressure Sensor Range/Performance
Quick Answer
The Evaporative Emission System (EVAP) control system pressure sensor detects pressure in the purge line. Common causes include Faulty Evaporative Emission System (EVAP) Pressure Sensor, Evaporative Emission System (EVAP) Pressure sensor harness is open or shorted, Evaporative Emission System (EVAP) Pressure sensor circuit poor electrical connection. Severity is Low - monitor the vehicle and repair when practical. The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.
- What it means
- P0451 Mercury indicates Evaporative Emission Control System Pressure Sensor Range/Performance.
- Common causes
- Common causes include Faulty Evaporative Emission System (EVAP) Pressure Sensor, Evaporative Emission System (EVAP) Pressure sensor harness is open or shorted, Evaporative Emission System (EVAP) Pressure sensor circuit poor electrical connection.
- Severity
- Low - monitor the vehicle and repair when practical.
- Can I drive?
- The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.
Code P0451 Mercury Description
What are the Possible Causes of the DTC P0451 Mercury?
- Faulty Evaporative Emission System (EVAP) Pressure Sensor
- Evaporative Emission System (EVAP) Pressure sensor harness is open or shorted
- Evaporative Emission System (EVAP) Pressure sensor circuit poor electrical connection
- Faulty Engine Control Module (ECM)
How to Fix the DTC P0451 Mercury?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
Code Tech Notes
2005-2008 Mercury Mariner
2006-2008 Mercury Mariner Hybrid
2005-2008 Mercury Mariner Factory Service Bulletin OBDII Code P0451
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0451 Mercury code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Frequently Asked Questions about P0451 Mercury Code
What does the OBDII code P0451 mean for a Mercury vehicle?
The P0451 code indicates a problem with the Evaporative Emission Control System (EVAP) pressure sensor, which is detecting a range or performance issue.
What are the symptoms of the P0451 code in a Mercury?
Common symptoms include an illuminated Check Engine Light, failed emissions tests, and in some cases, a noticeable fuel odor.
What causes the P0451 code to be triggered?
Possible causes include a faulty EVAP pressure sensor, damaged wiring or connectors, a clogged EVAP vent valve, or a leaking EVAP system.
Can the P0451 code affect drivability?
Typically, the P0451 code does not affect drivability, but it may lead to increased emissions or fuel odors if not repaired.
How do you diagnose the P0451 code on a Mercury?
Diagnosis involves checking the EVAP pressure sensor, inspecting wiring and connectors, verifying the integrity of the EVAP system, and using a scan tool to monitor sensor readings.
Can a loose gas cap cause the P0451 code?
A loose or damaged gas cap usually triggers a different EVAP-related code, but it’s still worth checking as part of the diagnosis.
How do you fix the P0451 code in a Mercury?
Repairs may include replacing the EVAP pressure sensor, repairing wiring or connectors, cleaning or replacing the EVAP vent valve, or addressing any leaks in the EVAP system.
Is it safe to drive with the P0451 code?
Yes, it’s generally safe to drive, but you should address the issue promptly to avoid potential emissions problems or fuel vapor leaks.
How much does it cost to fix the P0451 code?
Repair costs vary, ranging from $50 for a gas cap replacement to $200-$400 for sensor or wiring repairs, depending on the exact issue.
Can I clear the P0451 code without fixing it?
You can clear the code with an OBDII scanner, but it will likely return if the underlying issue isn’t resolved.
Discuss the causes and fixes for P0451 Mercury OBDII Code
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my check engine light came on, detected a ROM error, aal failed, back on went off after filling the gas, dealer said without light on, they don't know what should I do
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What model and year is your Mercury? You should wait until the light comes back ON. EVAP system codes will not cause any engine performance problem or damage your car. If comes back again, have the dealer inspected.
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check engine light on, and blinking overdrive light on, 2006 mercury mariner, 123,000 miles
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What codes did you get? the overdrive system or transmission is not related to the P0451 code.
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My Mariner 2005 3.0 Lt, V6, has check engine light on and show me a message "Service Emission system", could you help me, please? Thanks ¡¡
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There is a factory service bulletin for that code (See "Tech notes" above). The bulletin states that the condition may be caused by water/moisture or other contamination entering the fuel filler vent line and then freezing and/or causing a blockage. The bulletin suggest how to fix the problem,
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On my 08 mariner I have no check engine light, but does a period. 3 beep sequence. It's my first new car and I have no clue how this thing works. Any ideas?
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The beep could be for something else. Beside the beep, are there any driveability problems? Not sure you are able to get codes with beeps.
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