B1317 GMC – Inside Air Temperature Sensor

B1317 GMC Possible Symptoms

Engine Light ON (or Service Engine Soon Warning Light)

B1317 GMC Possible Causes

Faulty Inside Air Temperature Sensor,Inside Air Temperature Sensor harness is open or shorted,Inside Air Temperature Sensor circuit poor electrical connection,Faulty Instrument Panel Module (IPM)

B1317 GMC Description

The Instrument Panel Module (IPM) monitors the temperature sensors to maintain the comfort level inside of the vehicle. The temperature sensors are a 2 wire negative temperature co-efficient thermistor. The IPM applies 5 volts to internal input resistors that are connected to the signal circuits of the air temperature sensors. The IPM provides the ground to the air temperature sensors through the low reference circuit. The IPM monitors the voltage drop across the air temperature sensors and uses the inputs for automatic control calculations. When the air temperatures are cold, the resistance of the sensors are high and the voltage signals are high. When the air temperatures are hot, the resistance of the sensors are low and the voltage signals are low. The IPM converts the voltage values to count values where one volt is approximately equal to 51 counts.