What are the symptoms of a bad inertia switch on a Ford?
The inertia switch is a safety feature in Ford vehicles that cuts off the fuel supply in the event of a collision, preventing a potential fire. If the inertia switch is malfunctioning, it can cause various issues with your Ford's performance and safety. Here are the common symptoms of a bad inertia switch on a Ford.
Engine Won't Start
One of the most obvious signs of a bad inertia switch is if your Ford's engine won't start. The inertia switch is designed to interrupt the fuel supply when it detects a sudden deceleration, such as in a collision. If the switch is faulty, it may inadvertently cut off the fuel, preventing the engine from starting. This is the most common symptom of a bad inertia switch.
Fuel Pump Not Working
The inertia switch is connected to the fuel pump, and if the switch is malfunctioning, it can prevent the fuel pump from operating properly. This will result in the fuel pump not running, which can cause the engine to stall or fail to start. You may also notice a clicking sound from the fuel pump, indicating it's not receiving power.
Engine Stalling or Hesitating
If the inertia switch is intermittently cutting off the fuel supply, it can cause the engine to stall or hesitate during acceleration. This is because the engine is not receiving the necessary fuel, leading to a loss of power and performance.
Check Engine Light Illuminated
A bad inertia switch can trigger the check engine light on your Ford's dashboard. The vehicle's onboard diagnostics system will detect the issue with the inertia switch and illuminate the check engine light to alert you of the problem.
How to Diagnose a Bad Inertia Switch
- Check the inertia switch location and visually inspect it for any signs of damage or corrosion.
- Use a multimeter to test the switch for continuity. The switch should be closed (continuity) when the vehicle is at rest and open (no continuity) when the vehicle experiences a sudden deceleration.
- If the switch is not functioning properly, replace it with a new one.
Addressing a bad inertia switch is important for the safety and performance of your Ford vehicle. If you experience any of the symptoms mentioned above, it's best to have the issue diagnosed and repaired by a qualified mechanic as soon as possible.
How do you reset an inertia switch?
Once the switch has tripped it must be reset before attempting to restart the engine. The inertia switch is located behind the trim on the left-hand side of the vehicle, forward of the front door post, below the fascia. A finger access hole in the trim allows the driver to reset the switch.
How do I know if my Ford inertia switch is bad?
There are 2 ways to test it. You can test for power on both wires once the key is turned on. The fuel pump relay should send power to the inertia switch and if the switch is good and not tripped it should allow power to flow back out.
What are the symptoms of a bad fuel pressure switch?
The FTP sensor is used by the ECM to adjust the air/fuel mixture and ignition timing. A malfunctioning FTP sensor can cause the engine to run improperly, leading to rough idling. This symptom is often accompanied by a noticeable vibration or shaking sensation in the cabin of the vehicle.
When did Ford stop using the inertia switch?
The Web Site will prompt a phone call , I only work with online chat. The 2020 Explorer does not use an inertia switch for the fuel system anymore. Ford stopped using them in 2004.
