B0158 CADILLAC 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
First diagnose B0158 CADILLAC code
Check the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded terminals.
B0158 CADILLAC Tech NotesB0158 02: Ambient Air Temperature Sensor Circuit Short to Ground
B0158 05: Ambient Air Temperature Sensor Circuit High Voltage/Open
Cost of diagnosing the B0158 CADILLAC code
Labor: 1.0The cost of diagnosing the B0158 CADILLAC code is 1.0 hour of labor. The auto repair labor rates vary widely across the country, and even within the same city. Most auto repairs shops charge between $75 and $150 per hour.
B0158 CADILLAC Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
B0158 CADILLAC MeaningAir 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.
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