B0164

DTC B0159 or B0164

Circuit Description

The following DTCs are for the ambient air temperature sensor and for the inside air temperature sensor assembly:

* B0159 is for the ambient air temperature sensor.
* B0164 is for the inside air temperature sensor assembly.

The ambient air temperature sensor allows the HVAC control module to monitor the temperature of the air surrounding the front of the vehicle. The inside air temperature sensor assembly allows the HVAC control module to monitor the temperature of the air inside the passenger compartment. The module applies 5-volts to internal input resistors that are connected to the signal circuits of the air temperature sensors. The module provides ground to the air temperature sensors through the low reference circuits. The HVAC control module monitors the voltage drops across the air temperature sensors and uses the inputs for automatic control calculations. The HVAC control module also uses the ambient air temperature input to calculate the value of the ambient air temperature display. When the air temperatures are cold, the resistances of the sensors are high and the voltage signals are high. When the air temperatures are hot, the resistances of the sensors are low and the voltage signals are low.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

* DTC B0159 Outside Air Temperature Sensor Circuit Range/Performance
* DTC B0164 Passenger Compartment Temperature Sensor Circuit Range/Performance

Conditions for Running the DTC

* Battery voltage to the HVAC control module is greater than 8.7 volts and less than 16.5 volts.
* 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 0.09 volt or greater than 4.9 volts.

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.
* The HVAC control module use a default value of 25°C (77°F) for the Inside Air Temp. parameter.

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

Step 1 - Step 11:

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