AutoCodes – Chevrolet – B0509 Chevrolet

B0509 Chevrolet Code - Output Air Temperature Sensor 3 Circuit

Quick Answer

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. Common causes include 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. Severity is Low - monitor the vehicle and repair when practical. The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

What it means: B0509 Chevrolet indicates Output Air Temperature Sensor 3 Circuit.
Common causes: Common causes include 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.
Severity: Low - monitor the vehicle and repair when practical.
Can I drive?: The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

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Code Popularity 1,351

How popular is this code, among other codes? Low

Repair Importance Level

Low (Monitor) (1 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Mar 11, 2021

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code B0509 Chevrolet 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 Chevrolet - Output Air Temperature Sensor 3 Circuit - AutoCodes.com — B0509 Chevrolet Code - Output Air Temperature Sensor 3 Circuit

What does this mean?

What are the Possible Causes of the DTC B0509 Chevrolet?

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 to Fix the DTC B0509 Chevrolet?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code 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

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B0509 Chevrolet code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the B0509 Chevrolet code?

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

Need Help with the Code?

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

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about B0509 Chevrolet Code

1. What are the common symptoms of a B0509 Chevrolet OBDII code?

The common symptoms of a B0509 Chevrolet OBDII code may include issues with the heating, ventilation, and air conditioning (HVAC) system, poor engine performance, and potential illumination of the Check Engine Light.

2. What does the B0509 Chevrolet OBDII code indicate?

The B0509 Chevrolet OBDII code indicates a problem with the Output Air Temperature Sensor 3 Circuit, specifically with the sensor not functioning correctly or providing inaccurate readings to the vehicle's engine control module.

3. What are the possible causes of the B0509 Chevrolet OBDII code?

Possible causes of the B0509 Chevrolet OBDII code include a faulty Output Air Temperature Sensor, damaged wiring or connectors in the sensor circuit, or issues with the sensorâ€™s calibration.

4. How can I diagnose the B0509 Chevrolet OBDII code?

Diagnosing the B0509 Chevrolet OBDII code involves using a diagnostic scanner to retrieve the trouble code, inspecting the wiring and connectors related to the Output Air Temperature Sensor 3, and testing the sensor's functionality using a multimeter.

5. Can I drive my vehicle with a B0509 Chevrolet OBDII code?

It is generally not recommended to drive your vehicle with a B0509 Chevrolet OBDII code present, as it can affect the vehicle's performance and potentially lead to further engine or HVAC system issues.

6. How can I repair the B0509 Chevrolet OBDII code?

To repair the B0509 Chevrolet OBDII code, you may need to replace the faulty Output Air Temperature Sensor 3, repair any damaged wiring or connectors in the circuit, and clear the trouble code using a diagnostic scanner.

7. Is the B0509 Chevrolet OBDII code a serious issue?

While the B0509 Chevrolet OBDII code may not cause immediate harm to your vehicle, it is important to address the underlying problem promptly to prevent potential issues with engine performance and the HVAC system.

8. Can a DIY enthusiast fix the B0509 Chevrolet OBDII code?

Depending on your level of automotive repair knowledge and experience, a DIY enthusiast may be able to diagnose and repair the B0509 Chevrolet OBDII code by following detailed repair guides and using the necessary tools.

9. How much does it cost to fix the B0509 Chevrolet OBDII code?

The cost to fix the B0509 Chevrolet OBDII code can vary depending on the specific issue causing the code, the cost of replacement parts, and whether you choose to repair the vehicle yourself or seek assistance from a professional mechanic.

10. How often does the B0509 Chevrolet OBDII code occur in Chevrolet vehicles?

The B0509 Chevrolet OBDII code can occur sporadically in Chevrolet vehicles with certain models or years that are equipped with an Output Air Temperature Sensor 3, but the frequency of occurrence may vary based on driving conditions and vehicle maintenance.