Where Did the Ford Inertia Switch Go?

2008 Ford Escape Hybrid Inertia Fuel Shutoff Switch.
2008 Ford Escape Hybrid Inertia Fuel Shutoff Switch.

Remember how much time was spent trying to figure out why a newly repaired Ford vehicle wouldn’t start? Then only to find out that someone bumped the Ford Inertia Fuel Shutoff Switch during reassembly. You might have noticed that those switches, with the red button have disappeared. Let’s take a look at what happened to them.

In case you don’t know the inertia switch, it is designed to shutoff the fuel pump in the event of a collision, as to not create a fire hazard if a fuel line is damaged. Inertia from a crash was used to trigger the switch. This worked good for a collision, but the switch would sometimes trigger after hitting a large enough bump, leaving a driver stranded on the side of the road.

Occasionally a Ford vehicle would be towed in that would not start because the inertia switch needed to be reset. The inertia switch was reset by simply pushing the red button on the switch. The switch could also be manually pushed to turn off the fuel pump, which worked nice for turning off the fuel pump when servicing the fuel system.

Like it or hate it, Fords Inertia switch was still a great safety feature. But why then would Ford stop using them? The simple answer is, they haven’t. Granted modern Ford vehicles do not still use the switch with the red button, however they still utilize a fuel pump shutoff feature. The modern switch is much more accurate, so it won’t be as likely to leave someone stranded after hitting a pothole. You also cannot manually turn it on and off. The switch is activated by the restraints control module. So now, when you get a collision damaged Ford vehicle towed in that will not start, you cannot just push the reset button. Per the Ford repair manuals: “Should the vehicle shut off after a collision due to this feature, the vehicle may be restarted by first turning the ignition to the OFF position and then turn the ignition to the ON position. In some instances, the vehicle may not start the first time and may take one additional ignition cycle.”

So, this safety feature is still being used, it has just evolved to become more user friendly.

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