Patent ID: 8556505

Claim:
An apparatus for reading a temperature of a material, comprising: a thermistor communicable in temperature sensing communication with the material; a first resistor having a first resistance; a second resistor having a second resistance lower than the first resistance; a switch selectively controllable to electrically couple the first resistor and second resistor to the thermistor in a low temperature mode, and to electrically couple the second resistor to the thermistor and electrically decouple the first resistor from the thermistor in a high temperature mode; and an engine control module that determines a voltage differential value across the first resistor, second resistor, and thermistor in the low temperature mode and determines a voltage differential value across the second resistor and thermistor in the high temperature mode, wherein the engine control module triggers a thermistor diagnostic fault for voltage differential values within predetermined voltage differential value upper and lower ranges.