Abstract: A Low Pressure Warning Device, System and Method is disclosed. The disclosed system is compact, and low cost but has an extremely long term service life. Further disclosed is sensing means that actively monitors the pressure conditions of a pneumatic chamber without drawing electrical power. The disclosed preferred sensing means will further detects various conditions, including activation-, normal- and low-pressure conditions. Also disclosed is a device that is installable within the pneumatic tire of a vehicle such that it is theft- and tamper-resistant. The disclosed device is resistant to truck tire operating temperatures and is further provided with a protective casing to prevent damage or contamination of the system components. Still further disclosed are a transmitter and receiver that are configured to transmit and receive encoded signals to permit great flexibility in vehicle monitoring combinations, while also providing the localization of the pneumatic chamber experiencing a low pressure condition.