Tire Pressure Module: Description and Operation

TPMS RECEIVER

DESCRIPTION





1. Mode
1) Virgin State
^ The receiver as a sole part is shipped in this state. Replacement parts should therefore arrive in this state.
^ In this state, there is no sensor monitoring and no DTC monitoring.
^ The state indicates that platform specific parameters must be written to the receiver and that sensors are un-learned.





2) Normal State
^ In order for tire inflation state and DTC Monitoring to occur, the receiver must be in this state.
^ In this state, automatic sensor learning is enabled.





3) Test State
^ This state is only used in manufacturing plant to check RIF transmission between sensor and receiver.





2. Overview
^ Receives RIF data from sensor.
^ Uses sensor data to decide whether to turn on TREAD Lamp.
^ Learn TPM sensor for under inflation monitoring automatically.
^ Uses sensor information, distance traveled, background noise levels, Auto-learn status, short circuit output status, vehicle battery level, internal receiver states to determine if there is a system or a vehicle fault.

OPERATION

1. General Function
^ Auto-learn takes place only once per Ignition cycle.
^ On successful completion, 4 road wheel sensor ID's are latched into memory for monitoring.
^ Until Auto-learn completes, previously learned sensors are monitored for under inflation / leak warnings.
2. General Conditions to Learn New Sensors:
^ Receiver must determine that it is confident that sensor is not temporary:
a) Uses vehicle speed.
b) Uses confidence reduction of previously learned sensors.
^ Typical time at driving continuously over 12.4 mph(20 kph) to learn a new sensor is up to 20 minutes.
3. General Conditions to Un-Learn a sensor that is removed:
^ It takes less than 20 minutes at 12.4-18.6 mph(20-30kph).
^ Confidence reduction is dependent on time which vehicle is driven at speed greater than or equal to 12.4 mph(12 kph).