Gas sensor system

A gas sensor system comprising:

• a gas sensor having an oxygen pump cell electrically communicating with a first terminal and a second terminal, and an oxygen concentration detection cell electrically communicating with the second terminal and a third terminal, the gas sensor detecting the concentration of a specific gas contained in a gas under measurement;
• and
• a sensor control section which includes a first terminal potential detection circuit for detecting a first terminal potential of the first terminal and a third terminal potential detection circuit for detecting a third terminal potential of the third terminal and which controls the gas sensor through the first terminal, the second terminal, and the third terminal, wherein
• the sensor control section includes:
• an examination potential circuit which brings the second terminal to a predetermined examination potential;
• a first constant current circuit which supplies a predetermined first examination current to the oxygen pump cell through the first terminal;
• a second constant current circuit which supplies a predetermined second examination current to the oxygen concentration detection cell through the third terminal;
• terminal potential detection means for detecting the first terminal potential and the third terminal potential using the first terminal potential detection circuit and the third terminal potential detection circuit, before the gas sensor detects in an activated state the concentration of the specific gas contained in the gas under measurement, and in a state in which the second terminal is brought to the examination potential by the examination potential circuit, the first examination current is supplied from the first constant current circuit to the oxygen pump cell through the first terminal, and the second examination current is supplied from the second constant current circuit to the oxygen concentration detection cell through the third terminal;
• and
• wire breakage diagnosis means for determining whether or not the gas sensor has a wire breakage anomaly and a location where the wire breakage anomaly has occurred based on the detected first terminal potential and the detected third terminal potential.