Tire Pressure Sensor Warnings

I've got an '05 Explorer with about 13k miles. The tire pressure sensor
warning is about to drive me crazy. The dealer has replaced all 4 sensors
under warranty, with no relief. We've compared tire gauges, with mine about
3psi below his. He's telling me I'm not keeping them inflated, the weather
is cooling, etc. While the second argument is true, I don't buy it as the
cause. A couple questions -

1) Does anyone know at what psi these sensors are supposed to activate? I
had been running 35 psi on my gauge, and have increased to 38 psi. I'm not
comfortable taking it any higher.

2) These warnings NEVER go off immediately when I start driving. It may be
15 minutes later, maybe 2 hours later. It seems to me if the tire pressure
was actually too low, I would receive the warning immediately. Is that a bad
assumption on my part?

Any and all feedback is very much appreciated. Thanx, JW

The low pressure alarm has happened twice with my '05 during a two
year period. Both times were on the first really cool morning of the
fall. When I checked the tires, all four showed 29-30 psig. As you
know, the recommended pressure is 35 psig, so it looks like the alarm
goes off on mine when the pressure gets to the 29-30 psig range.

On Fri, 06 Oct 2006 14:12:26 GMT, "JW"
> wrote:

>I've got an '05 Explorer with about 13k miles. The tire pressure sensor
>warning is about to drive me crazy. The dealer has replaced all 4 sensors
>under warranty, with no relief. We've compared tire gauges, with mine about
>3psi below his. He's telling me I'm not keeping them inflated, the weather
>is cooling, etc. While the second argument is true, I don't buy it as the
>cause. A couple questions -
>
>1) Does anyone know at what psi these sensors are supposed to activate? I
>had been running 35 psi on my gauge, and have increased to 38 psi. I'm not
>comfortable taking it any higher.
>
>2) These warnings NEVER go off immediately when I start driving. It may be
>15 minutes later, maybe 2 hours later. It seems to me if the tire pressure
>was actually too low, I would receive the warning immediately. Is that a bad
>assumption on my part?
>
>Any and all feedback is very much appreciated. Thanx, JW
>

Check your driver's side door sticker for correct tire pressure for your
vehicle. My Explorer specifies 30 PSI for the front tires and 35 PSI for
the rear. That's cold pressure, as in hasn't been driven for awhile. First
thing in the morning is a good time to check. The specified pressure varies
based on year, tires, engines, etc. I don't have any experience with a
pressure warning system, but you could check the owner's manual to make sure
it won't go off if the pressure is too HIGH. Try a different Ford
dealership since this is still under warranty.

"JW" > wrote in message
. ..
> I've got an '05 Explorer with about 13k miles. The tire pressure sensor
> warning is about to drive me crazy. The dealer has replaced all 4 sensors
> under warranty, with no relief. We've compared tire gauges, with mine
> about 3psi below his. He's telling me I'm not keeping them inflated, the
> weather is cooling, etc. While the second argument is true, I don't buy it
> as the cause. A couple questions -
>
> 1) Does anyone know at what psi these sensors are supposed to activate? I
> had been running 35 psi on my gauge, and have increased to 38 psi. I'm not
> comfortable taking it any higher.
>
> 2) These warnings NEVER go off immediately when I start driving. It may be
> 15 minutes later, maybe 2 hours later. It seems to me if the tire pressure
> was actually too low, I would receive the warning immediately. Is that a
> bad assumption on my part?
>
> Any and all feedback is very much appreciated. Thanx, JW
>



--
Posted via a free Usenet account from http://www.teranews.com

Sticker for my '05 is inside the gas filler door and calls for 35 all
around.

On Fri, 6 Oct 2006 11:54:24 -0500, "Captain Coleman"
> wrote:

>Check your driver's side door sticker for correct tire pressure for your
>vehicle. My Explorer specifies 30 PSI for the front tires and 35 PSI for
>the rear. That's cold pressure, as in hasn't been driven for awhile. First
>thing in the morning is a good time to check. The specified pressure varies
>based on year, tires, engines, etc. I don't have any experience with a
>pressure warning system, but you could check the owner's manual to make sure
>it won't go off if the pressure is too HIGH. Try a different Ford
>dealership since this is still under warranty.
>
>"JW" > wrote in message
...
>> I've got an '05 Explorer with about 13k miles. The tire pressure sensor
>> warning is about to drive me crazy. The dealer has replaced all 4 sensors
>> under warranty, with no relief. We've compared tire gauges, with mine
>> about 3psi below his. He's telling me I'm not keeping them inflated, the
>> weather is cooling, etc. While the second argument is true, I don't buy it
>> as the cause. A couple questions -
>>
>> 1) Does anyone know at what psi these sensors are supposed to activate? I
>> had been running 35 psi on my gauge, and have increased to 38 psi. I'm not
>> comfortable taking it any higher.
>>
>> 2) These warnings NEVER go off immediately when I start driving. It may be
>> 15 minutes later, maybe 2 hours later. It seems to me if the tire pressure
>> was actually too low, I would receive the warning immediately. Is that a
>> bad assumption on my part?
>>
>> Any and all feedback is very much appreciated. Thanx, JW
>>

I just bought an '05 Explorer on Saturday and it was showing a Tire
Pressure Sensor Fault before I even left the dealership. They told me
to bring it back so they could either reprogram it or replace it. Mine
faults ever time I start the vehicle. Smply pressing the Reset button
on the dash seems to clear the fault. We'' see if they can actually fix
it.

I also saw a Low Tire Pressure warning yesterday morning when I went
out to wash it. It was a little cold, and it was a cold night.
According to the owner's manual, cold temperatures can effect the
output of these sensors. So when the tire warm up the warning will go
away, and it did for me yesterday.
--
Holmbrew

Good luck with the dealer. I made 3 trips to the dealer that sold me the
car. They kept telling me they couldn't do anything because the sensor was
not activated and I needed to bring it back when it was lit up. Since
they're 40 minutes away, that's a problem. I finally complained to the Svc
Mgr, who said make an appt and they would swap out the sensors. Did that,
called back after not hearing anything for 6 hours, the service writer said
"can't do anything because the sensor was not activated." Found another
dealer, he swapped out the four sensors. A week later it tripped again.

I can understand the sensors tripping out when cold on cold mornings. On
mine, I may drive interstate for 2 hours, then the sensors suddenly goes
off. No way that's cold tires. I've driven Explorers since '92, and survived
fine without this annoyance. These things are a royal ass-pain. They've gone
off so many times, there's no way I could take them seriously even if there
was a problem.

Good luck,
JW

"holmbrew" > wrote in message
ups.com...
>I just bought an '05 Explorer on Saturday and it was showing a Tire
> Pressure Sensor Fault before I even left the dealership. They told me
> to bring it back so they could either reprogram it or replace it. Mine
> faults ever time I start the vehicle. Smply pressing the Reset button
> on the dash seems to clear the fault. We'' see if they can actually fix
> it.
>
> I also saw a Low Tire Pressure warning yesterday morning when I went
> out to wash it. It was a little cold, and it was a cold night.
> According to the owner's manual, cold temperatures can effect the
> output of these sensors. So when the tire warm up the warning will go
> away, and it did for me yesterday.
> --
> Holmbrew
>

Well, my wife is going to take it in later this week to get a few other
things fixed at the same time. They made it sound like an easy fix, and
since it ALWAYS faults on vehicle start up, it is at least a
reproduceable problem.

The other thing with the sensor saying the tire pressure is low at a
low ambient temp seems reasonable. Since the pressure of a volume of
gas can be affected by temperature, it makes sense to me that my truck
was showing a low tire pressure when the ambient temp was cold. Your
problem sounds like something more than just a faulty sensor, perhaps
there are some bad wires associated with the sensor or something.

Hell, there is probably a way to jumper that sensor's circuit with a
small resistor that would fake the computer in to thinking it was
reading the correct pressure.