B0159

DTC B0159

CIRCUIT DESCRIPTION
The ambient air temperature sensor allows the HVAC control module to monitor the temperature of the air surrounding the front of the vehicle. The module applies 5 volts to internal input resistor that is connected to the signal circuit of the air temperature sensor. The module provides ground to the air temperature sensor through the low reference circuit. The HVAC control module monitors the voltage drop across the air temperature sensor and uses the input for automatic control calculations. When the air temperature is cold, the resistance of the sensor is high and the voltage signal is high. When the air temperature is hot, the resistances of the sensor is low and the voltage signal is low. The HVAC control module also uses the ambient air temperature input to calculate the value of the ambient air temperature display.

CONDITIONS FOR RUNNING THE DTC
- Battery voltage to the HVAC control module is greater than 8.7V and less than 16.5V.
- The ignition is turned ON.

CONDITIONS FOR SETTING THE DTC
The HVAC control module determines that the voltage applied to the input for the air temperature sensor is less than 0.09V or greater than 4.9V.

ACTION TAKEN WHEN THE DTC SETS
The HVAC control module uses a default value of 10°C (50°F) for the ambient air temperature display. The scan tool also displays 10°C (50°F) as the value for the Outside Air Temp. Raw parameter. This value will be displayed on the scan tool.

CONDITIONS FOR CLEARING THE DTC
- The DTC will become history if the HVAC control module no longer detects the condition that set the DTC.
- The history DTC will clear after 100 fault free ignition cycles.
- The DTC can be cleared with a scan tool.

TEST DESCRIPTION

Steps 1-11:

The number below refers to the step number on the diagnostic table.
2. Verifies that the condition that set the DTC is present.