Some of you know that I recently imported my Expedition into the UK.
Since that time a couple of weeks ago the tire pressure warning light has been on.
It seems that one of the sensors was damaged when I had new tires fitted prior to coming back to the UK.

Since I can't obtain the correct sensor here in the UK it has been replaced with a regular valve but the tire pressure warning light is now permanently on.

Does anyone know if there is a way to disable it...its very irritating having to reset the computer every time the engine starts!

I have posted this in the Expedition forum but hopefully someone here may know as well.

Thanks

Lenny

 

No I dont think so, I would suggest ordering the correct TPMS sensors and having them installed in your wheels.

 

I've done that (Thanks for your offer Brad), and had replacements sent from the States but for some reason the warning light is still showing.

 

I'm just "thinking out loud" here Lenny, since I don't have TPS on my f150 and I don't have a wiring diagram for it either.

Does the sensor signal go through the PCM or some other device before activating the idiot light? Is this something that needs to be "reset" in a controller somenow?

Also, is it possible the new sensor was not installed correctly? Or, was the damage to the original one not at the sensor at all but possibly in the circutry that "feeds" it?

Possibly, wreedKR might have some better information on this for you. He's rapidly becoming an "expert" on all thiings electrical.

- Jack

 

Thanks for that Jack.
Something strange just happened though. Up until now I can get rid of the low tire pressure warning by pressing 'reset'. The symbol of the tire still remains on the dash which is what has been irritating. Just now though I was on a slightly longer drive and there was a sudden 'bong' from the warning system and up came the message 'Tire sensor fault'.
I pressed reset and this time the little tire symbol disappeared !
Now though the 'sensor problem' warning appears each time I start up but at least the symbol disappears !
If I were in the States I presume I would just go into a dealership and have them reset the confuser, but I doubt the equipment over here would have that capability since the Expy is not sold here.

 

So again, just "thinking out loud" - the "system" (whichever one of the multitudinous systems is operating here), now "thinks" there is something wrong with the pressure sensor? But, once you "thank" it for telling you of this horrendous fault, it's happy and doesn't bother you again (until the next time you take the truck out to impress the sheep).

This really sounds more and more like a faulty installation or some damage to the sensor circuit (perhaps nothing more than a poor connection). The longer drive may have "cleared" the low pressure signal?

But, since there really IS a fault in the circuit, it's going to warn you about it each time you go for a drive? What a pain!

Is this circuit something you can get at and trace with a multimeter (assuming you are interested in doing this type of work)?

I really suspect the fault is something quite simple and easily fixed, once found. I can't believe the circuit is particularly complicated. My guess is it's a simple "pressure switch" that probably sends an OK signal as long as the pressure keeps it activated (closing an electrical circuit). If the pressure drops, the circuit opens. And maybe there's an additional series circuit connecting all the sensors that if "broken" tells the system: "sensor fault"?

Again, just throwing thoughts around - no expertise here! :o But, it's good to hear from you, regardless of the reason!

- Jack

 

Thanks for all that Jack.

I have to drive into South Wales today so a longer drive may throw up some answers. I'll get back to you when I have some more thoughts on the subject.

 

I believe that these things can be set via magnetics...

We were having an intermittent problem with a sensor on my wife's 04' Explorer and a friend forwarded me the reset procedure. I believe it's on my email at home, John... I forgot that I had this.

I'll dig it out and post it here once I get to it...

 

Just saw this, according to my service manuals the TPMS is controlled thru the VSM. (vehicle securty module) mounted behind rear seat.
I will see if I can find a reset procedure for the TPMS

 

Lenny,
Is there any way you can pull the DTC from the computer and post it? That way I can get you the exact repair procedure for the code you are getting.
If the light is on continuously then , 1. low tire pressure, or 2. TPMS sensors are not transmitting at all.
If the light flashes, 1. it is a single sensor fault , 2. No communication from VSM (probably not this if your doors unlock)

Also it says new sensors just cannot be installed, they must be installed and "trained" to the VSM. I think this is your problem.

Unfortunately you cannot do this without a special tool.
Tool is here:
http://cgi.ebay.com/ebaymotors/TPMS-...08061420r18346

 

Holey Cow! Wreed, you've just blown me away! I'm impressed! And it takes quite a bit to do that!

The "tool" sounds like a good lead to me.

- Jack

 

I like my workshop manuals.

 

Wreed -- does it say anything about resetting the TPMS via magnetics? I keep forgetting to pull that email up as I'm hardly ever online in the evenings at home.

I seem to recall that it could be done with a large magnetic and several procedures (like turn the key on, stand on one leg, recite the alphabet backwards beginning with the letter "R", turn the key off, engage 4wd twice, push the 3rd preset station on the headunit and then switch over to the AM dial then back to FM, pull fuse 38 three times after doing the hokey pokey, recite the constitution of the US, phone Regis, hook up a trailer, lower the tailgate thrice, open the hood, remove the air filter, turn the key back on, move the seat all the way forward and then all the way back, replace the air filter, crank up, turn off the engine, remove spark plug 7 and then contact the leader of the Suquamish tribe (he will instruct you how to proceed from there).

-RP-

 

I should also add that this procedure has to be completed within 15 seconds or you have to start over...

 

This is all starting to sound very complicated...Shall I just live with the problem.
I only have to press 'reset' every time I start up.
And with the price of gas here and the fact that the Welsh Hills are reducing my consumption to just about 13mpg, I actually won't be starting up very often !!