Why I can't get any readings after properly installed the STSM?

Before going through the below troubleshooting, make sure the device is connected properly.

App with Device

• Make sure you are on the latest version of the ZUS App.
• Make sure your phone's Bluetooth is on.

Device on vehicle

• Make sure the sensors are well screwed onto the valve stem.
• Make sure the receiver is well plugged in and you can see the three LEDs on top of the car-shaped receiver is constantly on.

Sensor Compatibility Check

The sensors can detect a tire pressure range from 0-46 psi (0-3.2 bar), you can check your tires' recommended pressure, if it's beyond the sensors range, then they won't be able to give out any readings. You may contact [e-mail] for the follow-up.

Battery Check

Power up the receiver, are the 4 LEDs on the in-car receiver all flashing green or grayed out? If they are all grayed out, we kindly suggest you check the battery levels by taking off one of the sensors, screw open the sensor cap, pull out the battery, and insert it back. Watch closely the corresponding tire location on the in-car receiver, will the GREEN LED start to flash or remain grayed out?

If the green LED remains all the way out, please change the batteries.
https://nonda.zendesk.com/hc/en-us/articles/360043945952-How-to-Replace-Sensor-Batteries