AutoCodes - OBDII Code List - B0509 CADILLAC

B0509 CADILLAC - Output Air Temperature Sensor 3 Circuit

Repair Importance Level: 3/3
Repair Difficulty Level: 3/3
Table of contents

B0509 CADILLAC Possible Causes

  • Faulty Output Air Temperature Sensor 3
  • Output Air Temperature Sensor 3 harness is open or shorted
  • Output Air Temperature Sensor 3 circuit poor electrical connection
  • Faulty Heating, Ventilation, and Air Conditioning (HVAC) Control Module

How do I fix code B0509 CADILLAC?

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 connector's pins.
How much do you know about cars?

Take the AutoCodes.com automotive tests and turbo-charge your car repair knowledge

Play Now

Tech Notes

B0509 05: Output Air Temperature Sensor 3 Circuit Short to Battery or Open
B0509 02: Output Air Temperature Sensor 3 Circuit Short to Ground

Cost of diagnosing the B0509 CADILLAC code

Labor: 1.0

The cost of diagnosing the B0509 CADILLAC code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle's make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.

Possible Symptoms

  • Engine Light ON (or Service Engine Soon Warning Light)

B0509 CADILLAC 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.
OBDII Code B0509 Cadillac - Output Air Temperature Sensor 3 Circuit - AutoCodes.com

More Information

Need more information on how to fix the B0509 CADILLAC code?
Get Access to Factory Service Manuals

Need more help?

Get the B0509 Cadillac code diagnosed by a professional: Find a repair shop in your area

Comments

Help us improve AutoCodes.com. Leave a comment below or tell us if the information above help you fix the code. What are the symptoms on your vehicle for the B0509 Cadillac code? Have you replaced any parts?
Any information is appreciated. Thanks
Top ⇧
Repair Importance Level: 3
 
1=Low 2=Medium 3=High What is this?
Repair Difficulty Level: 3
 
1=Easy 2=Moderate 3=Hard What is this?
How much do you know about cars?

Take the AutoCodes.com automotive tests and turbo-charge your car repair knowledge

Play Now