Circuit Description
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 circuit of the inside air temperature sensor assembly. The module provides ground to the inside air temperature sensor assembly through the low reference circuit. The HVAC control module monitors the voltage drop across the inside air temperature sensor assembly 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 resistance of the sensor is low and the voltage signal is low.
DTC Descriptor
This diagnostic procedure supports the following DTC:
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 inside air temperature sensor assembly 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 55°C (131°F) for the Inside Air Temp. 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. |
Diagnostic Aids
If the condition is not present, refer to Testing for Intermittent Conditions and Poor Connections .
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: HVAC Schematics Connector End View Reference: HVAC Connector End Views | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
Does the scan tool indicate that B0164 is a current DTC? | -- | Go to Step 3 | Go to Diagnostic Aids | |
3 |
Does the voltage measure near the specified value? | 5 V | Go to Step 4 | Go to Step 5 |
4 | Measure the voltage from the signal circuit to the low reference circuit of the inside air temperature sensor assembly. Does the voltage measure near the specified value? | 5 V | Go to Step 7 | Go to Step 6 |
5 | Test the signal circuit of the inside air temperature sensor assembly for an open, high resistance, short to ground, or short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 8 |
6 | Test the low reference circuit of the inside air temperature sensor assembly for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 8 |
7 | Inspect for poor connections at the harness connector of the inside air temperature sensor assembly. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 9 |
8 | Inspect for poor connections at the harness connector of the HVAC control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 10 |
9 | Replace the inside air temperature sensor assembly. Refer to Inside Air Temperature Sensor Replacement . Did you complete the replacement? | -- | Go to Step 11 | -- |
10 | Replace the HVAC control module. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 11 | -- |
11 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
