HVAC System - Manual

DTC B0158

Circuit Description

The body control module (BCM) monitors the outside air temperature sensor to display outside air temperature. The temperature sensor is a 2-wire negative temperature co-efficient thermistor. The BCM applies 5 volts to an internal input resistor that is connected to the signal circuits of the Outside air temperature sensor. The BCM provides the ground to the outside air temperature sensor through the low reference circuit. The BCM monitors the voltage drop across the Outside air temperature sensor and uses the input for automatic control calculations. When the outside 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 BCM converts the voltage value to a temperature value of Celsius and Fahrenheit to be displayed by the driver information center (DIC).

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B0158 Outside Air Temperature Sensor

This vehicle has DTCs which include DTC Symptoms. For more information on DTC Symptoms, refer to DTC Symptom Description.






Conditions for Running the DTC

The ignition is turned ON.

Conditions for Setting the DTC

The BCM detects the sensor signal circuit is less than 0.4-volt or more than 4.8 volts.

Conditions Taken When the DTC Sets

* The default value of 3°C (38°F) will be substituted for the outside air temperature sensor data by the BCM.
* The driver information center (DIC) will display the set temperature when ON.

Conditions for Clearing the DTC

* The DTC will become history if the BCM no longer detects a failure.
* The history DTC will clear after 40 fault-free ignition cycles.
* The DTC can be cleared by using a scan tool.

Test Description

Step 1 - Step 10:

Step 11 - Step 12:

The numbers below refer to the step numbers on the diagnostic table.
2. The operating range of the sensor is between 0.4-4.8 volts. If the DMM displays a value less than 0.4 volt or greater than 4.8 volts, then the sensor is performing outside of its designed limits.
3. Tests for the proper operation of the circuit in the high voltage range.
4. Tests for the proper operation of the circuit in the low voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to voltage.
5. Test the signal circuit for a short to ground.
6. Tests the signal circuit for a short to voltage, a high resistance, or an open.
7 Tests the low reference circuit for a high resistance or an open.