Yesterday the warning symbol came up on the dash display while driving so I pulled over checked the tire pressure. All four exactly the same 37psi where a set them from day 1. I get back in and start the truck, the warning is gone and has not returned (yet).

What are the odds that was just and electronic hiccup?

 

Odds ? It's a sure thing !
They do sometimes work .It did for me but I had gone about 20' when I realized there was a problem - a totally flat tire. The TPMS figured it out too !
Everything is computerized in vehicles today . Computers => glitches !

 

So 2 weeks after the first low tire pressure warning popped up on the instrument cluster it happened again but this time it was superseded by a message saying something like:

'blah, blah, blah faulty tire sensor' or something to that affect

I checked the pressure and all 4 were exactly the same at 35psi. The warning message turned off after a few minutes and I decided to bump up the tire pressure to 41 (side wall says 44psi cold max and tire label on the driver side door label shows 35psi max).

If I took it to the dealer service dept, which I absolutely hate doing, how would they determine if it actually is a faulty TPMS?

 

Any chance you have a code reader? I wonder if a fault like that is stored where a regular hand held can read it.......

Ultimately if it is a sensor malfunction, the dealer will find it by connecting to it.

 

Just got back from the dealer. They were able to go around and reset all 4 tires monitors with a handheld sensor and therefore (according to them) the TPMS is still good and does not need replacing.
We'll see.

 

Does the spare have a TPMS sensor as well? That is an issue with my current vehicle that many people don't think to check. I would think that the dealer would mention something to you if that was a possibility.

 

Physics. As the air temps drop this time of year so does your tire pressure. Heat up a tightly sealed vessel and see what happens. Typically this time of year you start to see some cold temps in the morning and the tire which may have slowly been leaking pressure is down to the tripping threshold. You might want to bump the pressure up a couple pounds higher than the threshold which I believe is 35 pounds for the F150. Remember to check again next spring when air temps get back up and moderate the tire pressure accordingly.

 

I know sometimes when its cold these lights come on, never happened to my truck but does happen to my buddys Moutaineer.

 

WoodsTruck,
I was aware of the psi change with outside air temp change but in my case the tire pressures were all still at 37, which is exactly what I set them at 1 year ago, when the tell-tale went off (twice).

Dman1,
When I went through the manual a few days ago I was check for a mention of a TPMS in the spare but did not find it. Does anyone know if there is one?

 

Checking them after driving a while is not the way to do it. Needs to be checked before driving anywhere. Your 37 could really have been 32 or less.

 

King,
I realize that I checked them both hot and cold, the difference was only 2 psi (37 hot and 35 cold). That is exactly at Fords recommend psi for my truck (per driver door tire label).

 

The spare does NOT have a TPMS, at least not from the factory. If you read the manual it tells you if you mount the spare for any reason, the message center will tell you that you have a Tire pressure problem. The truck is only capeable of reading 4 sensors at any one time.

 

Quoting myself:

'Just got back from the dealer. They were able to go around and reset all 4 tires monitors with a handheld sensor and therefore (according to them) the TPMS is still good and does not need replacing.
We'll see.'

Yea well the TPMS tell-tale went on again even after the service dept. claimed they "reset them" and everything is OK. I was on the freeway, in the fast lane and had to pull all the way to the right shoulder so I could risk my life to check the tire pressure, which of course was OK but how would I know if the tell-tale was working properly or not after the service dept. said its "OK"

I know, I know, take it back to the service dept blah, blah, blah....(see my post #3) "If I took it to the dealer service dept, which I absolutely hate doing".....reiterate..... I HATE GOING TO THE DEALER SERVICE DEPT!

 

I've been having the same problem. I haven't had time to take mine in yet though.

 

It appears that the tell-tale warning only comes on after driving on the freeway for 20+ minutes.
I set up another appointment with the service dept. for this Thursday. Don't know how they are going to pin point the faulty sensor and I don't think they want to remove all 4 tires, replace all 4 sensors and rebalance all 4 tires if only 1 may be the issue.