Tmps Replacement

[FRITZHERKY]

I recently had a tire problem while on a road trip and had tire worked on, Ever since tire warning light stays on. I have checked all 5 tires with a digital presure gauge and all ok. Is it posible to replace one tpms unit on a Lexus GX470?

[mann777]

This is how the GX TPIS works . Each wheel (including the spare tire on certain vehicles) has a tire pressure warning valve/sensor integrated into the air valve with a unique ID number that measures the tire pressure and tire temperature and then transmits the information to the antenna/receiver mounted inside the vehicle through a radio wave signal. This includes the 5th tire ( spare tire as well. The ECU of the vehicle is programmed and vallues are inputed of 5 tires with the labelled PSI during the delivery stage( mentioned on the door label) . You can increase or decrease these values thru the TIS ( only via the dealer ) But the tyre has to be installed ( spare tire). For if any reason the tire is removed or the sensor is removed from the wheel, there is a grommet there, which has to checked periodically . Also this sensor has a Lithium battery which needs to be replaced once in 5-8 years( average life span).

Normally this is how a warning is generated The ECU takes each tire pressure, tire temperature, and unique tire pressure warning valve/sensor ID information from the antenna/receiver and compares it to the specified

value, which was registered during PDS( Pre Delivery Service) If the information received does NOT match the specified value registered in the ECU, it will transmit a signal to illuminate the Tire Pressure Warning System Indicator Light located on the combination meter.

Hope i have enlightened about your doubt.