Back story:

I live at 8k feet elevation. New tires put on the last week of 2014 down in Denver. Same 18" size and rating, just different than OEM brand. PSI set to 65 front, 80 rear or so I was told. I did not verify the pressure settings, yes I should have.

All was fine for about 3 weeks then the TPMS started alarming. I checked pressure at home to find rear right about 5 lbs low, was 75, filled back to 80. I kept watch to make sure there wasn't a slow leak, does not seem to be leaking.

Took F350 in for the recall yesterday, service manager said they would reset the TPMS even though I mentioned I would just take it back to Discount Tire. Recall complete and no alarming TPMS until I was 15 miles away from the dealer, TPMS going off again.

I did not have time to go back to the dealer, so arrived home, left tires cool off to retrain the TPMS myself. Made sure fronts were at 65, rears at 80. Drove around for a couple of minutes staying above 20mph.

Followed the manual exactly and tried the retrain procedure 3 times but was never able to get the single horn beep while releasing air from the front left tire while in train mode. Yes, I got the initial single horn beep and window indication to train left front, but each time I attempted to release air, no single beep ever. Eventually, the train mode would timeout and give me the 2 horn beeps. Each time the training mode would fail, air up the tires to the proper levels, and restart the procedure.

Question: When releasing air starting with the left front, how long, time wise, before the single horn beep on a properly working TPMS? I would continue to release air and the pressure would get down to 35-40, I knew this was not right so stopped... filled tire back up and started over.

Something is making me believe I will need 1 or more TPMS sensors replaced.

Comments or help?

Thx.

 

Not sure if all Ford TPMS' are the same, but I had the same issue on my Escape. Figured out tires had been rotated and the L/F was now the L/R, but it was still the L/F as far as the cars computer was concerned. Same for the right side, obviously. Adjusted the procedure accordingly and all went well.

 

Sounds like you got a bad sensor, takes me about 5 minutes total to retrain mine. I do 65 front and rear... no need to run 80 when not loaded..


The retrain process is to teach the truck which tire is which and how much pressure it is supposed to have..

 

You are assuming that the cause of your TPMS warning is low tire pressure. There could be a fault with the system causing this that might leave a DTC. Oddball repairs I have come across were an emergency vehicle with RF interference caused by a radio and another with a faulty Smart Junction box. Sensors have been known to go bad as well but I would not think on an intermittent basis. None the less, a faulty sensor can and will leave a code if it's signal is missing.

When you were at the dealer did you have them actually perform a self test, check for DTCs or perform any diagnostics other than to retrain your TPMS sensors?

 

I've had them where thick window tinting wouldn't allow training unless the door was open or windows down.

 

To be honest, I'm not sure of what exactly was done at the dealer concerning the TPMS yesterday. What I was told is they had to release pressure from each tire as they were all about 10 lbs over each. I honestly found the tires being 10 over hard to believe. I use an analog dial gauge and have always found it to be fairly accurate and would have adjusted to dead on the recommended setting. Living at 8k feet would also mean the pressure should have decreased a couple pounds down in Denver.

This only started 3 weeks after replacing the OEM tires. No window film (although I had the window down anyway when retraining) and only electrical device "added" is I replaced the sub amp.

What didn't cross my mind is the sensors being in different position from OEM however I have had the wheels rotated a couple of times before the tires were replaced.

Looks like I will be playing my own version of concentration to see which wheel location is trained to which sensor.

 

Read the manual... the position is part of the relearn. BTW I used to live at the top of Little Deer Creek Canyon just before the Hog Back.. course that was in '75-'76

 

It should not matter where the tire/wheel/tpms module was previously located if the "retrain" procedure completes. That is the purpose behind retraining the TPMS.

I am sure glad the DRW's do not have the factory TPMS. I did add one of the Tire Minder systems for the truck and travel trailer.

 

I've read through the retrain process about 5 times now thinking I was missing something.


I guess I am uncertain then if retraining the TPMS is meant to relearn which sensor and pressure is at the left front wheel for the first attempt? If that is true, then there would have to be a TPMS fault on my truck, most likely the front left sensor since I get no indication of a single beep when in proper training mode while releasing air from that tire? And I say sensor since those were recently potentially touched when the tires were replaced.

Would you say that logic is correct or wrong?


It really sucks being an engineer as I have to over think everything :-/

 

got it. I was typing up my other response when you posted this.

 

The retraining procedures says to release air till you get a beep of the horn. Maybe you aren't releasing enough air quickly enough?

I am sure you have read the procedures enough to know them by heart by now. Not sure it matters, but did you drive the vehicle a few miles prior to starting the process of retraining? Says drive the vehicle for at least 2 minutes above 20mph before starting the retraining.

 

Thanks much for the help guys!

Yes, drove the vehicle for at least 2 minutes over 20mph before attempting and the air could not release any faster. I'm going to give it another attempt as I need to run to the store so will attempt when I return home.

 

Just a thought that popped into my head... the LEFT is the driver's side...

 

LOL....I and others like you know this but not everyone. That might be a problem for some who are not aware.

 

You are right on the money. The training procedure ALWAYS begins with the left front tire then you go to the right front, then right rear and end with the left rear tire to complete the training.

The most likely cause here is a damaged TPMS sensor. We commonly see this after new tires have been installed.