TPMS Sensor....WTF??

I don't have the sensors on the new tires. How can I disconnect the sensor on the spare?

 

I don't think you can do anything with the sensor in the spare that will cause the light to go out. With the other 4 sensors gone, I believe the TPM indicator will flash to indicate a fault. You can either disable the system or mask the indicator. You will probably not find a technician that will disable it for you as the federal law forbids that (except when sensors cannot be fitted to replacement wheels.)

 

I think your only option will be to disconnect the light itself which will require going into the dash console (see the LED replacement threads).

Removing the sensor from the spare won't do anything. Another option is to put the original sensors in a tube or a small tire and inflate it to the proper pressure:
http://www.tacomaworld.com/forum/wheels-tires/47465-tpms-light-old-solution-revisited.html

http://www.tacomaworld.com/forum/technical-chat/1184-my-tpms-sensor-diy.html

 

Hank makes good points here.

I will add a little to TPMS light operation. Not all vehicles use the exact same indicators for the system. Some use only one indicator that looks like a tire profile (fish bowl) with an exclamation point in it. It will be yellow in color. Others will have this light as well as another yellow indicator of the four letters "TPMS". The tire symbol is the low tire indicator and the "TPMS" light will be the "system fault" indicator. If you have only one or the other it will do both jobs. (I am writing this generic for all vehicles because the behavior is industry standard) The strategy works like this.

At key on the indicators will do about a two second "bulb check" where they all turn on and then go off. This is a chance to be sure the indicators actually work. The tire indicator will go out and stay out if there are no low tires detected. If a tire is below the programmed PSI by a specific amount, the low tire light will come right back on SOLID until the issue is corrected. These lights can come on going down the road if a tire goes low or a fault is detected. Many systems will also turn on a light if a tire is OVER the calibrated pressure range because this is also a potential safety issue. So just remember that SOLID lights are PRESSURE related. Sensors all have batteries, they are not replacement items but are expected to last for many years (just like lithium watch batteries). Most vehicle makers use sensors that "go to sleep" when the vehicle sits still for a while. This is designed to extend battery life. Those vehicles, when you fill up a low tire, will likely need to be driven above about 20 MPH for a couple of minutes for the system to receive the new pressure from the sensor and turn the low pressure light back off. All Toyota sensors that I have looked at transmit all the time. This is one of the reasons that Toyota sensor ID numbers must be registered to the vehicle module. That way it will only pay attention to your sensors instead of the car next to you on the road.

The second mode of operation is for a fault. If at key on you see the bulb check and then see a flashing light a system fault has been detected. The light will flash once a second for one minute and then go solid on. Usually this is caused by one or more missing or damaged sensors. Dead batteries will also cause it. If you have a vehicle serviced and there are no warnings when you take it in and the light flashes when you pick it up, one was damaged. If you are concerned with this happening, do the dance. Have the service consultant come out to the vehicle and sign off on a working system. Then before you pick it up, take the vehicle out for a test drive, over 25 MPH for five minutes or more and if the lights stay off there are no problems. If you get a solid light tomorrow a tire has gone low. Some vehicles are very sensitive to pressure (depending on make and system) and 1-3 psi will turn on the low pressure light. A slightly inaccurate gage with a big temperature change can turn on a light in a day.

I would never disable or hide a warning system from the driver. If you put on wheels with no sensors, the flashing light then solid will be an indicator to the driver that the safety system is not operating. It is kind of like an ABS light or SRS (airbag) light. If the light is on it indicates to the drive that the system is likely not available.

One last thing. All this information is for "direct TPMS" systems with sensors in the wheels. There were some vehicles with "indirect" systems that used wheel speed sensor data to detect low tires. A low tire would have to spin faster to keep up with an aired up tire. They used comparison to detect a low tire. There were issues with accuracy so most have gone to direct systems with sensors. Some vehicles still use the wheel speed signal for additional information on "spring rate" of the tire. If a pressure sensor is skewed, one way to find it is to look at the wave form of the wheel speed sensor over a bump. If a tire looks "springy" like when the pressure is low it may flag a low tire. Tire construction and quality can cause lights even when the pressure is correct.

NEVER use tire sealer in a tire with a sensor in it.

Sorry for the book, I hope the detail is helpful in understanding the systems on our vehicles today.

 

^^^^Thanks guys for your imput. How would I go about "masking" the indicator? I'm just tired of looking at that damn light.

 

^^^^^^^^^^^ This ^^^^^^^^^^

 

It is correct that '09s do not have a sensor in the spare. Mine doesn't. (My '08 FJ DOES have one in the spare and I suspect the Tacomas are the same.)

 

the tire store i went to for new tires checked tpms sensors before he took tires off and after he put he put new tires on he checked all 5 to be sure they were working

 

Similar question, Hijak: Just put on new tires and the warning light flashes until I start driving, then it goes solid. I checked all tires PSI including spare, all at 33psi (tried 35psi just to see and no effect).

So since it blinks until I drive for 100' then goes solid, does that mean the sensor(s) toast?

thanks

 

My 09 does have a sensor in the spare. Got too cold one day and the light came on and all the other tires were good..... it was the spare.

 

Did you mount the tires on the wheels you had? Are the sensors still on the truck?

If you still have sensors then you most likely have one or more that were damaged when the tires were mounted. The flashing indicates a SYSTEM FAULT not a low tire. The standard is for the flashing to continue for ONE MINUTE and then stay on. That is different from the look of a low tire. A low tire will just come on and stay on after the two second bulb check. The Flash at startup says problem and air hose is not likely to fix.

HTH

 

You can also just crack open the dash and take the light out. thats what i did for someone else who took there TPMS out....

 

Exactly what i needed to know, thanks.

And for the other one, my '09 has a sensor on the spare.

 

X2- I work for Firestone, this is most likely the problem. You have to be careful when taking the tire off not to damage the sensors. Techs brake them from time to time.

 

how tough is it to disassemble the dash to take the TPMS light out? (am I looking at a day job or 30 min job?)

 

Holy necrothread, you might want to start a new thread or find one newer than 10yrs ago. Sorry to be blunt but you’ll probably get more help that way.

 

are you a pathologist? never have I ever heard the prefix necro- applied to anything other than pathology specimens

 

Not a pathologist, although I’d probably make more money if I were.

 

LOL