Fuel Cutoff Switch Circuit
The P2543 code means the vehicle's onboard diagnostic system has detected: Fuel Cutoff Switch Circuit. This is a critical severity code.
- Keep driving?
- No — stop driving
- DIY difficulty
- easy
- Estimated cost
- $0 - $200 (parts and labor)
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Common Symptoms
- Engine will not start after minor impact
- Fuel pump not running
- No fuel delivery to engine
- Check engine light on
Probable Causes (Ranked by Likelihood)
- Inertia fuel cutoff switch tripped from impact Very High
- Faulty fuel cutoff switch High
- Wiring damage to cutoff switch circuit Moderate
- ECM not receiving cutoff switch reset signal Low
Frequently Asked Questions
Where is the inertia fuel cutoff switch?
On Ford vehicles it is typically located in the trunk, behind a kick panel in the rear cargo area, or under the dashboard. Check your owner manual for the exact location.
How do I reset the fuel cutoff switch?
Press the reset button on top of the switch. It is a simple push-button that pops up when tripped and resets when pressed down. Verify no fuel leaks before restarting.
Can hitting a pothole trip the fuel cutoff switch?
Yes. A hard bump, pothole, or even a curb strike can generate enough force to trip the inertia switch, cutting off fuel to the engine as a safety measure.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
-
Locate and reset the inertia fuel cutoff switch
-
Test fuel cutoff switch circuit for continuity after reset
-
Check wiring between cutoff switch and fuel pump relay
-
Verify fuel pump operates after switch is reset
Sources 1
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
Commonly Affected Vehicles
- 2008-2018 Ford F-150
- 2010-2019 Ford Escape
- 2008-2018 Ford Mustang
- 2010-2020 Ford Ranger
Related Codes
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