Tire Pressure Low Warning Came On Yesterday

[Barsoom]

Yesterday, after several hours of driving around town, the low tire pressure warning came on. This was shortly after driving through a puddled street. I pulled into a gas station and visually inspected the tires with no obvious low tires or nails. Today, I checked the pressure in each tire. The placard in the door says the cold PSI is 34 for all tires. Mine were at 40 or more.

 

I guess I now have to have my dealer check out the tire pressure monitoring system when I have the other Warranty work done.

 

sigh...

[TonyHzNV]

Yesterday, after several hours of driving around town, the low tire pressure warning came on. This was shortly after driving through a puddled street. I pulled into a gas station and visually inspected the tires with no obvious low tires or nails. Today, I checked the pressure in each tire. The placard in the door says the cold PSI is 34 for all tires. Mine were at 40 or more.

Did you have the tires rotated lately or otherwise change the position of any tire on the car? You didn't say. It's my understanding that the TPMS "knows" where each individual tire is located on the car and if you change their positions, the system has to be "taught" the new positions using a $50 Ford "teaching tool ". If you don't, you can get a tire pressure light. I have read this somewhere and there are videos about it on YouTube. Just my 2¢.

Edited January 4, 2015 by TonyHzNV

[Easy Rider]

On a system that will not display each individual tire, it doesn't need to "know" which is which.

 

The pressure transducers are located IN the valve stems.

Driving through water probably triggered the problem.

A close inspection might show one with a loose, missing or damaged cap letting water inside.

[TonyHzNV]

The pressure transducers are located IN the valve stems. Driving through water probably triggered the problem. A close inspection might show one with a loose, missing or damaged cap letting water inside.

Technically, the TPMS SENSORS are not located IN the valve stems, but rather attached to them. See the illustration in the Ford parts catalog here: http://www.fordparts.com/Commerce/PartDetail.aspx?n=dMAS1cRivT6ZQTjtazydRA%3d%3d&id=301665529&m=2&search=true&year=2013&make=Ford&model=Fusion

Whenever you change a tire the valve stem has to be replaced but the sensor is reused. I know it's a technicality but then, this IS a technical forum. ☺

 

If you check here, there is a spirited discussion of this subject: http://fordfusionhybridforum.com/topic/8564-program-tpms-on-2013-ffh/ I'm not sure where Hybridbear gets his info (see post #7), but I believe him ☺.

Edited January 4, 2015 by TonyHzNV

[Barsoom]

The manual says that driving for a few miles when the tries are properly inflated should make the message go away. So far, that hasn't happened.

 

I have not personally serviced the tires before. Before leaving California in October, I had my dealer perform a 10,000 mile service. The tires would have been checked and notated then.

[corncobs]

On a system that will not display each individual tire, it doesn't need to "know" which is which.

 

The pressure transducers are located IN the valve stems.

Driving through water probably triggered the problem.

A close inspection might show one with a loose, missing or damaged cap letting water inside.

That would makes sense but is unfortunately not the case. When I switched to my winter tires I had to re-teach all four wheels because front went to back and back to front.

 

What I do believe is that once the wheels have been at each location once the car knows from that point forward.

 

Because the wheels were not rotated since October as indicated by the OP and all pressures are correct you might have a failed one. There are batteries inside each TPMS so maybe there is a faulty one.

 

It should be an easy check to go into the teaching mode for the TPMS and see if the car can detect all 4 sensors.

[Easy Rider]

The manual says that driving for a few miles when the tries are properly inflated should make the message go away.

Is it proper to assume then that the manual does NOT say that they need to be "retrained" ??

 

And as long as each one is reporting valid data and there is only ONE idiot light, why does anybody or anything care if each is on the "right" wheel or not ???

 

Now......if all 4 go to zero at about the same time, that might be a different story.

[TonyHzNV]

Because the wheels were not rotated since October as indicated by the OP and all pressures are correct you might have a failed one. There are batteries inside each TPMS so maybe there is a faulty one.

That DOES seem to be the most logical answer but one wouldn't think that a battery on a '13 would have died already, though not impossible. I had my 2007 F150 with TPMS for 6 years and never had a low pressure light. Anyone have an idea what the average life of a TPMS battery is? Waldo, you out there? You seem to have a lot of "inside" information! ☺ Another thing that could cause this problem is installing the WRONG TPMS sensor (though not in this case). Both '13 &' 14 FFH's use 2 different sensors (depending on your VIN). One transmits on 315 MHz and the other on 433 MHZ so make sure you get the right one if you ever have to replace one. That is all.?

Edited January 4, 2015 by TonyHzNV

[corncobs]

I just saw this on MotorWeek and they said it they last about 3 tire changes but I don't remember the years they assumed.

 

If we assume tires last 40k that's 120k on the TPMS. IIRC the avg. mileage per year is 15k so that would give you 8-10 years.

[lolder]

Having a missing valve cap should not let water into a tire where it can damage a sensor. Any products have premature failures. That's what warranty's are for. I had a sensor battery failure after about ffour years in my 2010 FFH. The sensors are only powered when the wheel is turning and the warning would only come on after a period of driving that got less and less and eventually was on continuously. I changed it when re-tiring at COSTCO. Their price is less than most but you must be a tire customer

[TonyHzNV]

If we assume tires last 40k that's 120k on the TPMS. IIRC the avg. mileage per year is 15k so that would give you 8-10 years.

Thanks Corncobs! Since I don't read MotorWeek, that will remain a handy reference!

[billford]

Did you have the tires rotated lately or otherwise change the position of any tire on the car? You didn't say. It's my understanding that the TPMS "knows" where each individual tire is located on the car and if you change their positions, the system has to be "taught" the new positions using a $50 Ford "teaching tool ". If you don't, you can get a tire pressure light. I have read this somewhere and there are videos about it on YouTube. Just my 2¢.

I rotated my tires a few months ago, front to rear, without retraining them and no tire light has come on.

 

I think that if all the tire pressures stay the same it does not matter what position they are in. The control module knows that during the initial training, what sensor belongs to what position. But after that initial training, it does not matter where you move the tire.

 

However, if you rotated the tires and have not retrained them and the tire light comes on due to a sensor failure or low tire, there can be a problem. If the Tech uses a scanner and checks for codes and data, the tire will not be in the position where the control module thinks it is and an inexperienced tech may diagnose the wrong wheel.

 

So I guess it is best to retrain them after a rotation. But if you don't, it should not make the light turn on just because they were rotated, but it can cause a diagnostic problem if the light turns on later.

 

Also on vehicles which have different tire pressures front to rear, like pickup trucks, the tires must be retrained after rotation after the pressures are adjusted.

Edited January 4, 2015 by billford

[jeffo65]

Not sure, but don't the tires need to be within a certain percentage of each other? If one tire drops out of the established/monitored range it would set off the low tire message.

 

I suggest refilling the tires to a single tire pressure and then drive around a bit to see if the TPMS is reset.

[Easy Rider]

Having a missing valve cap should not let water into a tire where it can damage a sensor.

The key word there is "should".

I once had a tire go flat because the cap was loose, water got under the cap and it pushed the valve open when the temperature went WAY down and the water froze.

Flukes happen.

[GrySql]

The Ford TPMS units are battery powered and go into a 'sleep mode' when the car is stationary or off. The TPMS battery can fail, the TPMS sensor can fail.

According to Ford 'If the tires are properly inflated and the spare tire is not in use but the light remains on, contact your authorized dealer as soon as possible."

Sounds like the car needs to be looked at.

[Barsoom]

Having a missing valve cap should not let water into a tire where it can damage a sensor.

I have all of my valve caps.

 

I also know that my ties were rotated, because I scraped the rim of the front right tire a year ago, and that tire is now on the right rear.

Edited January 5, 2015 by Barsoom

[Waldo]

What does the message say? Does it say "tire pressure low" or does it say something else like "tire pressure system malfunction". That's a big key in diagnosing the problem, although if you've confirmed that the tires are all properly inflated then it means something in the system isn't working correctly.

 

Rotating tires will not cause the message. Having unequal tire pressures will not cause the message (assuming they are all above the minimum and under the maximum).

[corncobs]

 

Rotating tires will not cause the message. Having unequal tire pressures will not cause the message (assuming they are all above the minimum and under the maximum).

What's the maximum? Just for curiosity reasons.

[Barsoom]

It simply says "Tire Pressure Low."

 

The manual doesn't distinguish between different messages, either. The manual has a trouble-shooting chart that says if the message comes on and the tires are inlfated properly, then bring the car in for service to the monitoring system.

[Waldo]

It simply says "Tire Pressure Low."

 

The manual doesn't distinguish between different messages, either. The manual has a trouble-shooting chart that says if the message comes on and the tires are inlfated properly, then bring the car in for service to the monitoring system.

 

That most likely means you have a sensor that has somehow fallen out of calibration. If the system was not detecting 4 valid signals, it would say "TIRE PRESSURE SENSOR FAULT" or "TIRE PRESSURE MONITOR FAULT".

[Barsoom]

Here's more.

 

I ran a vehicle health report on Friday right after the warning came on. It called out two urgent issues:

 

1. Brakes & Suspension - URGENT Brake Warning... although none of the icons indicated are showing. After reading some more, maybe this is because I had the parking brake engaged while running the report? The report says to release the parking brake and rerun the report.

 

2. Checks, Fluids & Filters - URGENT Tire Pressure Monitoring System Warning...

 

Interestingly, Oil Life is 47%, but I had my first 10,000 mile service done in Octoer 2014. About a week after that, I drove the car from the San Francisco area to Houston, where I am now.

 

I won't be able to bring the car in for service for a week or so, so I'll report back after it's serviced. I know it's scary to think about driving with these kinds of warnings, but these may be false readings.

[FordService]

Yesterday, after several hours of driving around town, the low tire pressure warning came on. This was shortly after driving through a puddled street. I pulled into a gas station and visually inspected the tires with no obvious low tires or nails. Today, I checked the pressure in each tire. The placard in the door says the cold PSI is 34 for all tires. Mine were at 40 or more.

 

I guess I now have to have my dealer check out the tire pressure monitoring system when I have the other Warranty work done.

 

sigh...

Hi Barsoom,

 

Let me know when you head to your dealer for this. I can loop in your customer service manager for additional assistance.

 

Meagan

[Barsoom]

Thanks, Meagan. I will contact you shortly. I have not yet spoken directly to a service advisor; I made the appointment on-line. I also want to call the service department in advance because I'm new to the area. I had established a good relationship with my prior dealership that I will need to rebuild - not necessarily a good thing as it was born of all the repeated issues with the 2013 model.

[FordService]

Thanks, Meagan. I will contact you shortly. I have not yet spoken directly to a service advisor; I made the appointment on-line. I also want to call the service department in advance because I'm new to the area. I had established a good relationship with my prior dealership that I will need to rebuild - not necessarily a good thing as it was born of all the repeated issues with the 2013 model.

I completely understand. I'll keep an eye out for your message. :)

 

Meagan

[Barsoom]

I took my car in today. They said the pressure was a little higher than spec, and slightly imbalanced across the tires. They said the sensor was okay. It's odd that high pressure triggers a low pressure warning, but nothing surprises me anymore.