Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptors
DTC B0164: Passenger Compartment Temp Sensor Circuit Range/PerformanceDTC B0174: Output Air Temperature Sensor 1 (upper left) Circuit Range/Performance
DTC B0179: Output Air Temperature Sensor 2 (lower left) Circuit Range/Performance
DTC B0510: Output Air Temperature Sensor 3 (upper right) Circuit Range/Performance
DTC B0515: Output Air Temperature Sensor 4 (lower right) Circuit Range/Performance
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Inside Air Temperature Sensor Signal | B0164 | B0164 | B0164 | -- |
Upper Left Air Temperature Sensor Signal | B0174 | B0174 | B0174 | -- |
Upper Right Air Temperature Sensor Signal | B0510 | B0510 | B0510 | -- |
Lower Left Air Temperature Sensor Signal | B0179 | B0179 | B0179 | -- |
Lower Right Air Temperature Sensor Signal | B0515 | B0515 | B0515 | -- |
Inside Air Temperature Sensor Low Reference | B0164 | B0164 | B0164 | -- |
Upper Left Air Temperature Sensor Low Reference | B0174 | B0174 | B0174 | -- |
Upper Right Air Temperature Sensor Low Reference | B0510 | B0510 | B0510 | -- |
Lower Left Air Temperature Sensor Low Reference | B0179 | B0179 | B0179 | -- |
Lower Right Air Temperature Sensor Low Reference | B0515 | B0515 | B0515 | -- |
Circuit/System Description
The HVAC control module monitors air temperature through air temperature sensors. When the air is cold, the sensor resistance and signal voltage are high. When the air is warm, the sensor resistance and signal voltage are low. The HVAC control module requests A/C compressor clutch engagement and controls the appropriate mode and air temperature actuator door positions in order to maintain the selected air temperature on the HVAC control module.
The inside air temperature sensor is contained within the HVAC control module. The replacement of the inside air temperature sensor involves the replacement of the HVAC control module. The inside air temperature sensor provides the HVAC control module with the temperature of the air drawn through an aspirator from the passenger compartment across a sensor. A reference voltage is supplied to the sensor thermistor and the HVAC control module determines the voltage drop across that device which is proportional to temperature. As the air temperature increases, the resistance decreases and the voltage signal decreases. As the air temperature decreases, the resistance increases and the voltage signal increases.
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
The HVAC control module detects the air temperature sensor signal circuit is less than 2 counts or greater than 253 counts for 30 seconds.
Action Taken When the DTC Sets
A default value will be used for the sensor data by the HVAC control module.
Conditions for Clearing the DTC
| • | The DTC will become history if the HVAC control module no longer detects a failure. |
| • | The history DTC will clear after 50 fault-free ignition cycles. |
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the appropriate temperature sensor.
- Ignition OFF, test for less than 1.0 ohm of resistance between the appropriate low reference circuit terminal B and ground.
- Ignition ON, verify the appropriate scan tool temperature sensor parameter is greater than 250 counts.
- Install a 3A fused jumper wire between the appropriate signal circuit terminal A and ground. Verify the appropriate scan tool temperature sensor parameter is less than 5 counts.
- If all circuits test normal, test or replace the appropriate temperature sensor.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If less than the specified range, test the appropriate signal circuit terminal for a short to ground. If the circuit tests normal, replace the HVAC control module. |
| ⇒ | If greater than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the HVAC control module. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for HVAC control module replacement, setup, and programming |
