gatzdon
Well-Known Member
- Joined
- July 17, 2007
- Messages
- 347
- Reaction score
- 15
- City, State
- IL
- Year, Model & Trim Level
- 2000 Exp XLS 4WD V6 OHV
The full size spare on a Highlander has a TPMS in it and it most definitely will trigger the alarm if the pressure in it falls below the limit. The system is designed to read input from ALL wheels so that you don't end up with a flat/deflated spare when you need it most.
Peter
I cannot speak about all vehicles with absolute certainty, but on my '12 Explorer and most vehicles in general, the TPMS sensors do not start transmitting until the vehicle is travelling fast enough (about 20mph). This is to preserve battery life. The sensor has a switch that requires a minimum centrifugal force to close the switch and turn on the sensor.
That said, I can see all sensors and sensor values on my '12 Ex using Forscan Lite. There are only four sensor inputs for the four wheels. Forscan Lite would be a quick and easy way to see which sensor is reporting a fault or low pressure. The sensor location in the TPMS is dependent on the four sensors being trained in the correct order at your last tire rotation.
Faults that don't stay with a single sensor are indicative of RF interference.