TPMS - low tire pressure light will not go away
 

i had the low tire pressure message and light come on back when i was visiting california, about 3 weeks ago..i checked the tire pressure, and a couple tires were maybe 5 psi low at the most.. i aired them back up to the right pressure (as stated on the door pillar sticker) and the damned light/message is still coming on.. how do I reset the TPMS? it says in the manual to just drive the truck 20mph+ for about 2 mins after getting the tire pressure correct, and the light/message should turn off. i have done that...

The same thing happened to me a while back. You will need to run the TPMS reset procedure as outlined in the manual. It's not hard but you have to run around to each tire and release air as per the procedure. You should be fine after that. (I copied and pasted the procedure from the manual)

TPMS reset procedure

The TPMS reset procedure needs to be performed after each tire
rotation on vehicles that require different recommended tire
pressures in the front tires as compared to the rear tires.

WARNING: To determine the required pressure(s) for your
vehicle, refer to the Safety Compliance Certification Label or
Tire Label located on the B-Pillar or the edge of the driver’s door. See
Vehicle loading - with and without a trailer in this chapter for more
information.

Overview

To provide the vehicle’s load carrying capability, some vehicles require
different recommended tire pressures in the front tires as compared to
the rear tires. The tire pressure monitoring system (TPMS) equipped on
these vehicles is designed to illuminate the low tire pressure warning
light at two different pressures; one for the front tires and one for the
rear tires.

Since tires need to be rotated to provide consistent performance and
maximum tire life, the tire pressure monitoring system needs to know
when the tires are rotated to determine which set of tires are on the
front and which are on the rear. With this information, the system can
detect and properly warn of low tire pressures.

TPMS reset tips:

• To reduce the chances of interference from another vehicle, the TPMS
reset procedure should be performed at least three feet (one meter)
away from another Ford Motor Company vehicle undergoing the TPMS
reset procedure at the same time.
• Do not wait more than two minutes between resetting each tire sensor
or the system will time-out and the entire procedure will have to be
repeated on all four wheels.
• A double horn chirp indicates the need to repeat the procedure.
Performing the TPMS reset procedure

It is recommended that you read the entire procedure before attempting.

1. Drive the vehicle above 20 mph (32 km/h) for at least two minutes
and then park in a safe location where you can easily get to all four tires
and have access to an air pump.
2. Place the ignition in the off position and keep the key in the ignition.
Tires, Wheels and Loading
3. Cycle the ignition to the on
position with the engine off.
4. Turn the hazard flashers on then
off three times. This must be
accomplished within 10 seconds.
If the reset mode has been entered successfully, the horn will sound
once, the TPMS indicator will flash and the message center (if
equipped) will display TRAIN LEFT FRONT TIRE. If this does not
occur, please try again starting at Step 2.
If after repeated attempts to enter the reset mode, the horn does not
sound, the TPMS indicator does not flash and the message center (if
equipped) does not display TRAIN LEFT FRONT TIRE, seek service
from your authorized dealer.
5. Train the TPMS sensors in the tires using the following TPMS reset
sequence starting with the left front tire in the following clockwise
order:
• Left front (Driver’s side front tire)
• Right front (Passenger’s side front tire)
• Right rear (Passenger’s side rear tire)
• Left rear (Driver’s side rear tire)
6. Remove the valve cap from the valve stem on the left front tire;
decrease the air pressure until the horn sounds.
Note: The single horn chirp confirms that the sensor identification code
has been learned by the module for this position. If a double horn is
heard, the reset procedure was unsuccessful, and must be repeated.
7. Remove the valve cap from the valve stem on the right front tire;
decrease the air pressure until the horn sounds.
Tires, Wheels and Loading
8. Remove the valve cap from the valve stem on the right rear tire;
decrease the air pressure until the horn sounds.
9. Remove the valve cap from the valve stem on the left rear tire;
decrease the air pressure until the horn sounds.
Training is complete after the horn sounds for the last tire trained
(driver’s side rear tire), the TPMS indicator stops flashing, and the
message center (if equipped) displays:
TRAINING COMPLETE.
10. Turn the ignition off. If two short horn beeps are heard, the reset
procedure was unsuccessful and must be repeated.
If after repeating the procedure and two short beeps are heard when the
ignition is turned to off, seek assistance from your authorized dealer.
11. Set all four tires to the recommended air pressure as indicated on
the Safety Compliance Certification Label or Tire Label located on the
B-Pillar or the edge of the driver’s door. See Vehicle loading - with and
without a trailer in this chapter for more information.

The tire pressure warning goes when there is 10lbs difference, make sure ALL your tires are correctly inflated. Mine went off the first day I had my truck and I found the dealer had the tire pressure too low, it visually looked good but was low none the less and set the warning off.

what about the spare tire? Does it have a TPMS? Might be worth a check anyways. OR, you could have a bad sensor. Ony way to find that out is a dealer experience.... ;)

I have problems with this in the Spring and Fall months where temperatures fluctuate greatly between day and night. I like to keep the pressures down near the low pressure threshold for ride and tire wear reasons, but when the temperature drops 40 degrees the 4 psi difference will set off the TPMS warning. The system is supposed to reset itself once you have properly inflated the tires and drive a certain distance. I have only had this happen twice out too many times to count.

I usually have to do the manual relearn to make the light go away. I know of other people that have had the system reprogrammed to a lower pressure so that it is not an issue. I haven't made time to take the truck to the dealer to have it taken care of. Not all dealers will make that change for you either.

Oh I forgot to mention, no sensor in the spare either!

Funny. I was asked this question yesterday (sensor in the spare).
I didn't know the answer.

We dropped at least 35 degrees F since this time yesterday.
It will warm back up another 25 this weekend.
My fix:
The tires I find are similar to the DEF tank sensors.
You have to add a certain amount to make it happy.
I found 70 PSI on my ContiTrac's solved most of my issues while empty.
It would alert at 62 but airing up to 65 would not reset the alert.
I took the slightly rougher ride over the headache of a potential:
(Do da do, do da do, do da do)..........

The couple times last winter when my TPMS went off, I found a quick fix was to Run the low tire up to Max pressure ( 80 psi for my tires) Do a little driving, Then lower the tires to the desired pressure that is above the trigger point. Light would go off.

Never had to go thru the learning process detailed above.

Yeah. That's what happened to me. I had the rears at 65 and it didn't sound the alarm until one night it got cold. Then I had to go all the way to 80 and drive.

I figured that out after first going to 70 and driving and then 75 and driving some more. 80 and drive was the magic formula.

And that was about all of that I was going to take so I went and got the threshold reduced on the rear to make it same as the front. To get it done I first had to fight it out with the dealer where I bought the truck and I lost that round. The second dealer I went to I also had to fight but I won that argument by agreeing to pay. It cost me $47.50 but I consider it money well spent.

Frankly, I hate TPMS but now at least it doesn't harass me anymore and I don't have to teach it which tire is where when I rotate them.

On Edit: And while I'm ranting about TPMS let me rant a little more and suggest that in the 21st century I don't think it is too much to ask for the goddam system to tell me **which** tire is low when it decides to start lighting up lights.

Amen, Alex! Mercedes vehicles will show each tire pressure by location on the screen. It can't be that difficult to make the system that is already in place go that little extra distance. After all, it knows what position the tire is in and it seems to know the pressure so why not just transfer that information to the screen.

Amen brother. :-jammin

Make sure your neighbors grab a lawn chair and a drink so they can watch you work through the reset process.
If you screw up, start over!

At least I felt my neighbors were looking out their window once the horn honked a few times and see me running from tire to tire waiting for another honk.

thanks for all the replies, i am going to try what you guys have suggested.. i agree with 720Deere - why can't the stupid thing tell you WHICH tire is low..maybe they figured if they did that, you would just check the low one and not ALL of them...must be a method to their madness.. all i know is, this electronic computer stuff is annoying..what happened to the good old days of doing it the hard(actually - easy) way?

Some dumb mass was too busy programming a compass to show a truck in the middle, and to tell me how many degrees sideways and upward I was sitting ,....... yeah that's useful on a rock crawler. How many have used these tow vehicles for rock crawling lately?

LMAO......so true.

I had my dealer set all 4 positions to the minimum setting, believe he said 50psi was as low as the IDS software would let him set the BCM settings to. I haven't rotated tires yet, hopefully, he did what he said he did, and I'll be able to avoid the training process when I do rotate. With the empty truck I've been running 65psi front and 55psi rear, no idiot light on the dash.