Code B110, Outside Temperature Sensor Circuit: Notes

The outside air temperature sensor is a thermistor located behind grille. The BCM applies and monitors a 5-volt signal to sensor on circuit No. 735. When sensor is cold, its resistance is high; therefore, BCM will see a high monitored voltage. As sensor warms, its resistance becomes less and signal voltage is pulled low through sensor ground circuit No. 736. This signal voltage will vary between 5 volts (open circuit) and zero volts (shorted circuit).

Code B110 will set if ignition is on and signal voltage indicates less than -31°F (-35°C), which is open circuit voltage, or greater than 137°F (58°C), which is shorted circuit voltage. During the time failure is present, a substitute temperature reading will be used to allow continued operation of the climate control system. The outside air temperature reading, display BCM data display BD26, will indicate the actual sensor reading.

1. Checks to see if open circuit reading is due to circuit or sensor. If open circuit reading changes to a shorted circuit reading after jumping sensor terminals, BCM and wiring are okay.
2. By applying a ground to various points in the circuits, an open can be isolated by observing whether parameter display can be changed from an open reading to shorted reading.
3. Checks to see if shorted circuit reading is due to circuit or sensor. If reading changes from shorted circuit to open circuit after disconnecting sensor, BCM and wiring are okay.