B0158 - Ambient Air Temperature Sensor Circuit
Repair Importance Level:
Repair Difficulty Level:
Possible causes
- Faulty Ambient Air Temperature Sensor
- Ambient Air Temperature Sensor harness is open or shorted
- Ambient Air Temperature Sensor circuit poor electrical connection
- Faulty Heating, Ventilation, and Air Conditioning (HVAC) Control Module
Tech notes
B0158 02: Ambient Air Temperature Sensor Circuit Short to GroundB0158 05: Ambient Air Temperature Sensor Circuit High Voltage/Open
Possible symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
B0158 Description
Air temperature sensors allow the Heating, Ventilation, and Air Conditioning (HVAC) Control Module to monitor the temperature of the discharge air in the HVAC ducts. 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 circuit. The HVAC control module monitors the voltage drops across the air temperature sensors and uses the inputs for automatic control calculations. When the duct air temperatures are cold, the resistances of the sensors are high and the voltage signals are high. When the duct air temperatures are hot, the resistances of the sensors are low and the voltage signals are low. The HVAC control module converts the voltage values to count values where 1 volt is approximately equal to 51 counts.
B0158 Information for specific makes
- B0158 BUICK Ambient Air Temperature Sensor Circuit
- B0158 CADILLAC Ambient Air Temperature Sensor Circuit
- B0158 CHEVROLET Ambient Air Temperature Sensor Circuit
- B0158 GMC Ambient Air Temperature Sensor Circuit