DocJohn wrote:Okay, let's set the record straight here (Source = 2004 Solara factory service manual)...
1. The tire pressure monitor system in the gen 2 Solara DOES NOT sense air pressure in the spare.
2. The tire pressure monitor system in the gen 2 Solara DOES NOT actually sense tire pressures at all, but instead senses rotational rates in each of the 4 wheels. This is known as an indirect tire pressure indicator (TPI) system. If one tire has a lower pressure than the others it will have a slightly faster wheel rotational rate and trip the “pressure” warning indicator light.
Are you sure about that? I believe its quite opposite actually - ie direct. Look at toyota's diag tool - for every tire [not sure about the spare] the computer gets fed temp, tire position [on car], psi, and rpm. - if either is messed up, it trips the light.
Dont believe me? Try the following:
Rotate tires - the light will come on and
KEEP COMING ON UNTIL YOU DO A HARD RESET - the system must re-learn tire positioning.
Drive fast [90ish] on a dry road - depending on quality of air in your tire it will heat up too much and make system send an alarm [which goes off after it cools down]
LETS GET THIS THING STRAIGHT:
RTFM [read the fine manual

] - The system does NOT need to be reset on regular basis. That is the whole idea! As per user manual, the light will go off by itself once the tire is returned to normal pressure.
Soft-resetting it manually does nothing but remove the alert for 2-3 miles of driving.
After tire rotation or pressure adjustment you MUST DO A HARD RESET.
This includes playing with ignition key and holding the reset button for about 30 sec; then driving the car in a particular manner for about an hour - once again, RTFM [page 132 of user manual?]
Search for my other posts detailing this.
Follow the steps for a hard reset and you can too be tire-pressure-warning-light-free
Cheers, Vic