TPS Light 2008 Ranger

[bogthebasher]

Hi, I am new to this forum and did a quick search for relevant posts so if already asked and answered I apologize in advance. I had snow tires installed a few weeks ago (not by Ford) onto new steel rims including TPS (Tire Pressure Monitor) modules for each tire. This is a horrendously expensive route to go by the way. Anyhow all was fine until four days later when my TPS light came on and stayed on. On startup it blinks for a while and then stays on. The manual says that a 2 minute run-in at greater than 20km/hr is required once the TPS is resent so the truck can 'relearn' the fact that TPS is in and functioning. The tire shop said the TPS system in the truck must have gone to sleep and did not record the fact that the tires were sending valid signals and did anothr reset and things look good again. My question is: Does anyone have experience or knowledge of the TPS going to sleep? The theory is that normally while runing the tires send an 'I am here and alive' signal quite often to the TPS monitor to keep it awake but while shut off and parked it only sends this signal every six hours or so to save battery life and perhaps during that interval the TPS simply forgot about the tires permanently. To me this kinda sounds like hogwash but bow to the greater knowledge and experience of this group.