Technician A says that all temperature sensors are PTC devices that decrease in resistance as the temperature increases. Technician B says that some vehicle manufacturers use a stepped ECT circuit inside the PCM to broaden the accuracy of the sensor. Which technician is correct?
A) Technician A only
B) Technician B only
C) Both technicians A and B
D) Neither technician A nor B

Question

Quizplus · Accepted Answer

Technician A is incorrect because most temperature sensors used in vehicles are NTC (Negative Temperature Coefficient) devices, meaning their resistance decreases as temperature increases, not PTC as stated. Technician B is correct because some vehicle manufacturers do use a stepped ECT (Engine Coolant Temperature) circuit within the PCM (Powertrain Control Module) to improve the accuracy of the sensor across different temperature ranges.

Technician a Says That All Temperature Sensors Are PTC Devices