Tire Pressure Monitoring System problems of the 2004 Ford Expedition

The contact owns a 2004 Ford Expedition. The contact stated that the turn signals, the hazard lights, and the cigarette lighter had become inoperable. The tpms warning light was illuminated. The dealer and the manufacturer were not notified of the failure. The vehicle was not diagnosed or repaired. The failure mileage was unknown.

04 Expedition. Tire pressure monitoring system not working properly, when tire pressure is set to 35 psi per factory setting on door, tpms goes off. According to the dealer the tire pressure is correct and the tires are fine. Tpms still not working properly.

04 Expedition. Tire pressure monitoring system not working properly, when tire pressure is set to 35psi per factory setting on door, tmps goes off. According to the dealer the spec on the tmps is 3-5psi below set tire pressure which should be 35psi factory setting. The dealer spoke to the Ford tech they said to increase the tire pres to 39 psi, the dealer set the pres to 40psi. The tmps has not gone off, but my concern is it working . The sensor is actually set 5psi higher than the recommended pressure, and if the sensor is working now. Is the sensor in a condition that does not allow it to work. In my profession, medical ventilation repair, if a pres sensor is pushed to its limit it has a tendency to stay in this position (stuck). If the tire does have a problem will it go off, the tmps has gone off continually since it was new. It has been in the dealers service at least 3 documented times and numerous times they just checked the tire press and adjust the press. Ford sheet number 17030, of Ford suggested fixes. Tire pressure changes approximately 1 psi per 10deg of temp change. To clear tmps warning, set tire psi to spec with a digital gauge note to reduce false tmps warnings or ride harshness during tire service or pdi, the dealer set tire pressure to 35psi with a digital meter and we still get the light/message. If the tire pressure changes 1 degree for every 10 degree temerature change, set at 40psi in presscot where I live and driving to phoenix could make the press in the tire greater than the max tire pressure on the tire. The max on the tire is 44psi. This is also the case in presscot winter vs. Summer. I don't believe that adding tire press is a correct fix. The tmps to what I have read doesn't alarm you to overpress, which could cause lack of traction in an emergency swerve. You would not have the same traction as the tire set at a lower press. Ford should be required to make the tmps work as intended with the correct press stated on the driver door.