: TPMS Sensor going bad?



Mrsanders3960
08-30-12, 11:51 AM
I wanted to see if anyone else had this type TPMS issue: I have a 2008 STS SB1 3.6 with 17in wheels. My RF tire reads 24 and every time I start the car it tells me I have a low tire. When I drive the tire heats up (live in TX) and the light goes off and the DIC message goes away, but it still only reads about 25-26. I have had the tire checked at a tire shop, no leaks and the pressure in the tire when manually checked is 32. I have had a sensor go out and had to replace before but the DIC told me to check the system and I was able to locate which tire sensor was bad. My question: Is this possibly the sensor in the wheel or the computer acting up? Any one else have experience?

Midnight
08-30-12, 12:23 PM
I've had a intermittent sensor problem for awhile, usually it just figures out that the sensor is nuts and says so, but a few days ago it read low, and I had to pull over to check the tire before getting on the highway. Tire was fine. A bit later the sensor started working again, but yeah they can definitely read the wrong pressure, it may not be as common as it just going "out".

dkozloski
08-30-12, 03:24 PM
The TPMS should indicate within a pound or so what a hand gauge reads at the same time. TPMS reads absolute pressure corrected to 29.55 in.hg. If the local atmospheric pressure is something else TPMS will read erroneously. A hand gauge would read gauge pressure. If TPMS and gauge are not agreeing somewhat the TPMS is FUBAR and should be replaced.

EChas3
08-30-12, 07:53 PM
The batteries in the TPMS do go bad and replacement isn't very practical. Problems are pretty rare and I've been lucky so far. They aren't very expensive aftermarket. The hardest part is being sure you're buying the right ones.

When I need one, I'll probably buy a set from Tire Tack.

AllWheelEric
08-30-12, 10:38 PM
If the pressure reading seems way off, are you sure that the car is reporting on the correct tire? For example, if the tires were rotated front to back without reprogramming, perhaps it's the right rear that is soft when the car reports right front.

dkozloski
08-31-12, 01:56 AM
Any decent tire shop or well equipped mechanic ought to have a good TPMS test set. I have a Kent-Moore J-46079 that reads out all the TPMS sensor data including ID numbers and also provides simulated data to the auto in question. OTC sells a very similar tool. Sometimes you can find them on Ebay.

Midnight
08-31-12, 10:42 AM
When I need one, I'll probably buy a set from Tire Tack.

Haha.. Tire Tack.. worst tire store ever!

curtc
08-31-12, 11:08 AM
Haha.. Tire Tack.. worst tire store ever!

Agreed.

dkozloski
08-31-12, 11:38 AM
I think they're great. They ship quickly and have a very reasonable freight rate to Alaska.

Ludacrisvp
08-31-12, 11:46 AM
Haha.. Tire Tack.. worst tire store ever!

Nice...

KRSTS
08-31-12, 04:27 PM
I order my last set from them. Delivered in two days and no taxes - woo-hoo:cloud9:

Loren
09-01-12, 01:46 PM
I had the same problem and about went nuts trying to get the pressure correct in that one tire. After using three different gauges and raising and lowering the pressure I gave up and took it to the dealer. I found out that when tires are replaced and if the rims are not put back on the wheel they were on previously this can happen since the sensor had no idea which wheel it is on, just what the pressure is. Also, when the tires are rotated the same thing can happen. Solution, have the dealer reprogram the sensors so they show correctly what the current wheel location is. From the owners manual:
The TPMS sensor matching process was started
but not completed or not completed successfully
after rotating the vehicle’s tires. The DIC message
and TPMS malfunction light should go off once
the TPMS sensor matching process is performed
successfully. See “TPMS Sensor Matching Process”
later in this section.
If you are a DIY kinda guy, go for it:
TPMS Sensor Matching Process
Each TPMS sensor has a unique identification code.
Any time you replace one or more of the TPMS sensors
or rotate your vehicle’s tires, the identification codes
will need to be matched to the new tire/wheel position.
The sensors are matched to the tire/wheel positions in
the following order: driver side front tire, passenger
side front tire, passenger side rear tire, and driver side
rear tire using a TPMS diagnostic tool. See your
dealer/retailer for service.
The TPMS sensors may also be matched to each
tire/wheel position by increasing or decreasing the tire’s
air pressure. When increasing the tire’s pressure, do
not exceed the maximum inflation pressure indicated on
the tire’s sidewall. If using this method to match
TPMS sensors, the complete procedure outlined below
must be performed within 15 minutes of the vehicle
being stationary.
To decrease air-pressure out of a tire you can use the
pointed end of the valve cap, a pencil-style air pressure
gauge, or a key.
You will have one minute to match the first tire/wheel
position, and five minutes overall, to match all four
tire/wheel positions. If it takes longer than one minute to
match the first tire and wheel, or more than five
minutes to match all four tire/wheel positions, the
matching process stops and you will need to start over.

The TPM matching process is outlined below:
1. Set the parking brake.
2. Press the push-button ignition switch to Acc.
3. Using the keyless access transmitter, lock and
unlock the vehicle’s doors.
4. Press the lock and unlock buttons, at the same
time, on the keyless access transmitter. A single
horn chirp will sound, indicating that the TPMS
is ready, and the sensor matching process
can begin.
5. Start with the driver side front tire.
6. Remove the valve cap from the valve stem.
Activate the TPMS sensor by increasing or
decreasing the tire’s air pressure for five seconds,
or until a horn chirp sounds. The horn chirp,
which may take up to 30 seconds to sound,
confirms that the sensor identification code has
been matched to this tire position.
7. Proceed to the passenger side front tire, and repeat
the procedure in Step 6.
8. Proceed to the passenger side rear tire, and repeat
the procedure in Step 6.
9. Proceed to the driver side rear tire, and repeat the
procedure in Step 6.
10. After hearing the confirming single horn chirp for the
driver side rear tire, a double horn chirp will sound to
signal the tire matching mode is no longer active.
Press the push-button ignition switch to Acc.
11. Set all four tires to the recommended air pressure
level as indicated on the tire and loading information
label.
12. Put the valve caps back on the valve stems.

Rushnack
10-12-12, 10:39 PM
OMG, what a process that is... I just bought my 2008 STS V-6 with 46 k on it.. 2 days later the TPMS lites up.. I see it shows that all 4 tires are not exactly the same PSI.. And it also will show sometimes the LF not even register..

EChas3
10-13-12, 06:18 PM
US models have just one receiver. Naturally there are four transmitters, one in each tire stem. Chances are you've got one going bad. They aren't expensive but if you don't buy from a reputable vendor (Tire Rack, etc.) get assurance that you're buting the right type.

A dealer (or someone with a Tech II and the know-how) have a quicker matching procedure.

tomm
10-18-12, 07:26 PM
I had one changed at sams Club for $30 and I think $10 to re-balance the tire. Have one more sensor giving me the same issue and getting ready to replace that one as well. Not sure how many years the batteries last but being mine is a 2005 I doubt the original batteries have much life left.

EChas3
10-18-12, 09:13 PM
I think there was one member posting a refurb. At that price, I wouldn't bother.

So far so good for me. Do they recharge themselves from motion or just that long lasting?

Mullah88
10-18-12, 11:05 PM
My LF tpms is also acting up. Some days it reads out but sometimes, its straight blank and then starts reading again after 10mins of me driving the car.

Rushnack
10-24-12, 12:35 AM
Is there any way to just Disable the TPMS ???

curtc
10-24-12, 12:38 AM
A TechII device could possibly disable the feature all together...Would take a trip to the dealer though to find out, may not do it as it is technically considered to be a safety feature.

KRSTS
10-24-12, 07:10 PM
My LF tpms is also acting up. Some days it reads out but sometimes, its straight blank and then starts reading again after 10mins of me driving the car.

Same thing happened to me about a year ago. Then it stopped and hasn't done it since. No dealer would disable since it is a federally mandated safety device. Also, vehicle will not pass inspection in most states if the warning light is illuminated. You don't have a lot of options I'm afraid.

EChas3
10-24-12, 08:17 PM
At the risk of being offensive, if you don't like the upkeep on the STS, own a different car.

Mullah88
10-27-12, 03:54 PM
up keep is not the issue, my 1998 sts seville is more stable than my 06! thats a shame

EChas3
10-27-12, 04:51 PM
Our '98 Seville STS had more problems (especially the aggravating intermittant sort) than our new STS's combined, culminating with HG's. It was roomier, with a softer ride but like most (if not all) FWD's handled poorly under throttle. The new ones have more features & when fully-equipped, are an amazing example of applied technology.

YMMV