AutoCodes – GMC – B393B 2017 GMC Sierra

B393B 2017 GMC Sierra Code - Air Conditioning Compressor Valve Control Circuit

Quick Answer

This A/C system uses a conventional clutch to engage and mechanically turn the compressor and a variable displacement solenoid valve to alter the amount of displacement created by the turning of the compressor. Common causes include Faulty Air Conditioning Compressor, Air Conditioning Compressor harness is open or shorted, Air Conditioning Compressor circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: B393B 2017 GMC Sierra indicates Air Conditioning Compressor Valve Control Circuit.
Common causes: Common causes include Faulty Air Conditioning Compressor, Air Conditioning Compressor harness is open or shorted, Air Conditioning Compressor circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 324

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 17, 2023

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B393B 2017 GMC Sierra Description

This A/C system uses a conventional clutch to engage and mechanically turn the compressor and a variable displacement solenoid valve to alter the amount of displacement created by the turning of the compressor. The Heating, Ventilation, and Air Conditioning (HVAC) Control Module provides both switched battery voltage and a pulse width modulated ground to the variable displacement solenoid valve. When the A/C switch is pressed, the HVAC Control Module grounds the variable displacement solenoid using a Pulse Width Modulation (PWM) signal in order to determine the amount of compressor displacement. The performance of the A/C compressor is based on adjusted interior temperature and engine load. The Diagnostic Trouble Code (DTC) sets when a PWM greater than 10% is sent but no current is read back.

OBDII Code B393B 2017 GMC Sierra - Air Conditioning Compressor Valve Control Circuit - AutoCodes.com — B393B 2017 GMC Sierra Code - Air Conditioning Compressor Valve Control Circuit

What does this mean?

What are the Possible Causes of the DTC B393B 2017 GMC Sierra?

Faulty Air Conditioning Compressor
Air Conditioning Compressor harness is open or shorted
Air Conditioning Compressor circuit poor electrical connection
Faulty Heating, Ventilation, and Air Conditioning (HVAC) Control Module

How to Fix the DTC B393B 2017 GMC Sierra?

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 is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B393B 2017 GMC Sierra 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 B393B 2017 GMC Sierra code?

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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 B393B 2017 GMC Sierra Code

1. What does the OBDII code B393B mean on a 2017 GMC Sierra?

The code B393B indicates an issue with the Air Conditioning Compressor Valve Control Circuit, typically involving a malfunction in the electrical control or wiring of the A/C compressor valve.

2. What are the symptoms of code B393B on a 2017 GMC Sierra?

Common symptoms include the air conditioning not cooling properly, the A/C system not engaging, or intermittent cooling performance.

3. What causes code B393B to appear in a 2017 GMC Sierra?

Possible causes include a faulty A/C compressor control valve, damaged wiring or connectors in the control circuit, or a malfunctioning A/C control module.

4. How do you diagnose code B393B on a 2017 GMC Sierra?

Diagnosis involves inspecting the wiring and connectors for damage, testing the A/C compressor control valve for proper operation, and checking for any A/C system-related module faults.

5. Can a blown fuse cause the B393B code on a 2017 GMC Sierra?

Yes, a blown fuse in the A/C system circuit can disrupt power to the compressor valve, triggering the code.

6. How serious is the B393B code on a 2017 GMC Sierra?

While not an immediate safety concern, it can prevent the A/C system from functioning properly, reducing comfort during hot weather.

7. Can I drive my 2017 GMC Sierra with the B393B code active?

Yes, but the A/C system may not work as intended, which could be uncomfortable in extreme temperatures.

8. How do you fix code B393B on a 2017 GMC Sierra?

Repairs may include replacing the A/C compressor control valve, repairing or replacing damaged wiring or connectors, or reprogramming the A/C control module if necessary.

9. How much does it cost to repair the B393B code on a 2017 GMC Sierra?

Repair costs can vary depending on the issue but may range from $150 to $500 or more, depending on whether the compressor valve or wiring needs replacement.

10. Can low refrigerant levels cause the B393B code on a 2017 GMC Sierra?

Low refrigerant levels generally donâ€™t trigger this specific code but can cause A/C performance issues. It's important to check refrigerant levels during diagnosis.