2010 Cadillac CTS Sedan AWD V6-3.6L Page 190
2. Ignition OFF, test for less than 10 ohms between the following low reference circuit terminal and ground.
* Inside air temperature sensor terminal 2.
* Ambient temperature sensor terminal B.
瀚慖f greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the HVAC
control module.
3. Ignition ON, verify the appropriate scan tool Air Temp Sensor parameter is less than -35掳C (-39掳F).
瀚慖f greater than the specified range, test the following signal circuit terminal for a short to ground. If the circuit tests normal, replace the
HVAC control module.
* Inside air temperature sensor terminal 1.
* Ambient temperature sensor terminal A.
4. Install a 3A fused jumper wire between the following signal circuit terminal and the low reference circuit terminal. Verify the scan tool Air
Temp Sensor parameter is greater than 85掳C (185掳F).
* Inside air temperature sensor terminal 1 and 2.
* Ambient temperature sensor terminal A and B.
瀚慖f less 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.
5. If all circuits test normal, test or replace the air temperature sensor.
Component Testing
1. A thermometer can be used to test the sensor off the vehicle in warn and or cold water. Sensor Resistance Table (See: Heating and Air
Conditioning/Specifications/Electrical Specifications) for this test.
2. Test the ambient air temperature sensor by varying the sensor temperature while monitoring the sensor resistance.
3. Compare the readings with the Temperature VS Resistance table and verify that the resistance is within 5 percent of the specification.
瀚慖f not within the specified range, replace the sensor.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Ambient Air Temperature Sensor Replacement (See: Heating and Air Conditioning/Ambient Temperature Sensor / Switch HVAC/Service
and Repair/Ambient Air Temperature Sensor Replacement)
* Inside Air Temperature Sensor Replacement (Left Hand Drive) (See: Heating and Air Conditioning/Cabin Temperature Sensor /
Switch/Service and Repair/Inside Air Temperature Sensor Replacement)Inside Air Temperature Sensor Replacement (Right Hand Drive) (
See: Application and ID)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for HVAC control module replacement, setup, and
programming
B0163
DTC B0158 or B0163
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provides an overview of each diagnostic category.
DTC Descriptors
DTC B0158 03
- Outside Air Temperature Sensor Voltage Below Threshold
DTC B0158 07
- Outside Air Temperature Sensor Voltage Above Threshold
