PTC Sensor: Notes

PTC (Positive Temperature Coefficient) sensors also change resistance based on temperature. In a PTC sensor as the temperature goes up the resistance also goes up. The increase in resistance causes the voltage drop across the sensor to increase and the input voltage signal at the control module increases.

Fig 1: PTC Sensor Circuit Diagram

Courtesy of BMW OF NORTH AMERICA, INC.

Typical Application of A PTC Type Sensor: 

• Exhaust Temp Sensor.
• Transmission Temp Sensor.