TPMS Sensor Description and Operation

Description

1. 1
   Function

   • Detecting pressure, temperature, acceleration and battery status, transmit the information to the ECU by wireless radio frequency.
   • The wheel location is identified by comparing the wheel pulse of the ECS (ABS) with the acceleration sensor values (upper line).
2. 2
   Structure and Features

   • Four (4) sensors are installed on each wheel of the vehicle.
   • The frequency conversion type is FSK, normally using the High Line.
3. 3
   Mode

   • It consists of the initial factory mode (EOL test mode), the stop and drive mode, and the automatic learning mode.

• Wheel angular speeds differ from each other in the following cases:

1. 1
   Slip on each axle occurs differently.
2. 2
   The turning radius (curve radius) for each wheel is different.
3. 3
   Tire wear, internal pressure, tire characteristics, etc. differ for each tire.

• The TPMS sensor transmits the RF signal only at a specific phase (tire tilt angle) in learning mode.
• The TPMS receiver checks the phase information of each tire (tire tilt angle) when receiving RF signals from the sensor.
• Each time RF signals from sensors with IDs 1, 2, 3 and 4 are received, the ID with the highest correlation between the phases of each collected wheel is transmitted. (In other words, each time an RF signal is received, the tire phase is transmitted to the most consistent wheel.)
• The TPMS sensor transmits the RF signal at 16-second intervals in learning mode.
• After stopping or parking for more than 19 minutes, the automatic learning function is performed at each driving position.
• The sensor switches to parking mode when stopped or parked for more than 15 minutes. When acceleration of more than 4g (15-20 km/h) is detected in parking mode, it converts to the first block mode.

1. 1
   Normal Mode Function

   • Whenever IGN is on, the cluster can check the TPMS unit via the CAN communication line.

   [Normal Operation]

   • The cluster flashes for 3 seconds, then turns off.

   

   [Abnormal Operation]

   • The cluster flashes for 1 minute, then turns on.

   

2. 2
   Virgin Mode Function

   • TPMS has not learned the sensor IDs.

   [Normal Operation]

   • The cluster flashes for 3 seconds, then turns off for 3 seconds (repeats).
3. 3
   Low Tire Pressure Warning Lamp Function

   • TPMS unit detects low pressure.

   [Normal Operation]

   • No low-pressure tires.

   [Low Tire Pressure Warning Lamp On]

   • Low-pressure tire present.
   • Tire pressure is below the lamp illumination condition.

   

4. 4
   Malfunction Indicator Lamp Function

   • TPMS unit detection system malfunction.

   [Normal Operation]

   • No system malfunction.
   • The TPMS cluster lamp turns off.

   

   [Malfunction Indicator Lamp On]

   • System malfunction present.
   • The cluster flashes for 1 minute, then turns on.

   

5. 5
   Receiver Exchange Position: Diagnostic equipment (including the TPMS exciter) performs the following tasks.

   1. The vehicle must be entered with the code.
   2. Enter the VIN.
   3. Allows entry of the sensor ID.
   4. IG OFF after 10 seconds. (Check "TPMS" to determine whether the lamp is on)