Why is my low tire pressure light still on after changing to a spare?

Ford Trucks Forum
1

I had a flat tire over the weekend and had to put on the spare. I filled it up and it’s holding pressure, but the low tire pressure light is still on. It even blinks sometimes, but everything looks fine. Does anyone know why the light is still on or how to make it go away?

2

Your spare tire doesn’t have a TPMS sensor, so the system thinks it has no pressure since it’s not reading anything from it.

3

You might need to replace the TPMS sensors.

4

Are you still using the spare tire? If your regular tire is still flat or low on pressure, or if it’s too far from the vehicle, that could be why the light is still on.

5

Tara said:
Are you still using the spare tire? If your regular tire is still flat or low on pressure, or if it’s too far from the vehicle, that could be why the light is still on.

Yes, I’m using a full-size spare and I’m waiting to replace the regular tire after I get paid. Why is the light going off because of the spare?

6

@Umbrielle
The spare tire doesn’t have a sensor, so the system gets no reading from it.

7

@Umbrielle
The system is probably sensing the low pressure from your flat tire. Or if the tire with the sensor is too far away from the vehicle, it can trigger the light too.

8

Tara said:
@Umbrielle
The system is probably sensing the low pressure from your flat tire. Or if the tire with the sensor is too far away from the vehicle, it can trigger the light too.

That makes sense. Thanks for explaining!

9

@Umbrielle
The spare tire isn’t registering any air pressure, so the system thinks there’s an issue with your regular tire.

10

When the light blinks, it’s usually signaling a fault. Your vehicle is over 10 years old, so it might be time to replace the sensors. The internal batteries only last 10-12 years, and yours are already 14 years old. You’ve gotten your money’s worth, so you’ll need a new set. You could have the system scanned to find which sensor is causing the issue. After replacing it, you’ll need to have it registered to the computer using a TPMS scan tool. Then the next one will likely fail, and you’ll have to keep doing this. Replacing all 4 sensors will involve labor and some dismounting of tires, but it should last another 10 years.