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.





2. Overview
- Receives RF data from sensor.
- Uses sensor data to decide whether to turn on TREAD Lamp.
- 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 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 (20-30 kph).
- Confidence reduction is dependent on vehicle speed greater than or equal to 12.4 mph (12 kph).