Base Tire Pressure Monitoring

BASE TIRE PRESSURE MONITORING

The tire pressure monitoring system is designed to operate without loss of function for all OEM tire construction for this vehicle. The wheel sensor shall monitor tire pressure, air temperature inside the tire, wheel acceleration and the sensor internal battery status for all four active road tires. The sensor will broadcast this information, along with a unique 32 bit ID, to a central receiver circuit located inside the WIN. The information received by the WIN will be decoded and stored in memory (RAM) in the WIN. If a "warning or "fault" condition exists, the WIN will send a bus message request to illuminate the yellow telltale and to sound the chime.

If the WIN detects a warning or fault condition at ignition key "on" it will wait ten seconds +/- 10 % before sending the first request to illuminate the yellow telltale. This will assure that the display module has concluded its bulb check period. The display module will request a chime once per ignition cycle for each "warning" or "fault" condition detected. A "warning" or "fault" condition will remain enabled until the problem causing the condition is corrected and removed/reset.

The WIN shall continuously monitor for the receipt of tire pressure RF message transmissions from the wheel sensors during both the ignition key "on" and key "off" cycles. The wheel sensor ID's and the location of each sensor (e.g. Tire 1, Tire 2 etc.) are stored in the WIN non-volatile memory during the initial Manufacturing Plant Process, or during a service procedure, as required. The recommended "placard pressure", "low-pressure threshold" and "Hysteresis Pressure Values" for the tires installed on the vehicle, are learned by the WIN from the Front Control Module (FCM) configuration during the initial Manufacturing Plant Process, or during a service procedure, as required. The WIN upon learning the placard pressure via the bus then thru a matrix within the WIN software applies the appropriate "Low Pressure Threshold" and "Hysteresis Pressure Values" (Note: For vehicles with optional wheel/tire sizes and significantly different tire placard pressures, the placard pressure value is programmable using a scan tool to accommodate the customer selected wheel/tire combinations recommended by Chrysler). In the event the wheel/tire is changed to a combination recommended by Chrysler which has a different Placard Pressure from the tires the vehicle was built with during Manufacturing, the "Placard Pressure" must be updated in the Front Control Module (FCM) using the diagnostic tool. Confirm the replacement wheel/tire placard pressures to the Tire Inflation Pressure (Placard) Label associated with the replacement wheel/tire.

The TPM System will continue to warn the driver of low tire pressure as long as the condition exists, and will not turn off the indicator lamp until the tire pressure is at or above the Low Pressure (lamp) OFF threshold (see placard table below). The system will automatically update and the TPM warning lamp will extinguish once the updated tire pressures have been received.

The tire pressure will vary with temperature by about 1 psi (6.9 kPa) for every 12°F (6.5°C). This means that when the outside temperature decreases, the tire pressure will decrease. Tire pressure should always be set based on cold inflation tire pressure (placard pressure). This is defined as the tire pressure after a vehicle has not been driven for more than 3 hours - and in outside ambient temperature. The tire pressure will also increase as the vehicle is driven - this is normal and there should be no adjustment for this increased pressure. For a system fault, the system will return to normal once the WIN receives a valid transmission from that sensor location