AutoCodes – GMC – P0647 2015 GMC Sierra

P0647 2015 GMC Sierra Code - Air Conditioning Compressor Clutch Relay Control Circuit High Voltage

Quick Answer

When the Air Conditioning (A/C) switch is pressed, the Heating, Ventilation, and Air Conditioning (HVAC) control module sends an A/C request message to the Engine Control Module (ECM) via serial data. Common causes include Faulty Air Conditioning (A/C) Compressor Clutch Relay, Air Conditioning Compressor Clutch Relay harness is open or shorted, Air Conditioning Compressor Clutch Relay 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: P0647 2015 GMC Sierra indicates Air Conditioning Compressor Clutch Relay Control Circuit High Voltage.
Common causes: Common causes include Faulty Air Conditioning (A/C) Compressor Clutch Relay, Air Conditioning Compressor Clutch Relay harness is open or shorted, Air Conditioning Compressor Clutch Relay 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 157

How popular is this code, among other codes? Low

Repair Importance Level

Low (Monitor) (1 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jul 17, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0647 2015 GMC Sierra Description

When the Air Conditioning (A/C) switch is pressed, the Heating, Ventilation, and Air Conditioning (HVAC) control module sends an A/C request message to the Engine Control Module (ECM) via serial data. The ECM then grounds the A/C compressor clutch relay coil control circuit, closing the relay contacts. The closed relay contacts provide voltage to the compressor clutch causing it to engage. The Diagnostic Trouble Code (DTC) will be set when the ECM detects a short to voltage at the A/C compressor clutch relay control circuit.

OBDII Code P0647 2015 GMC Sierra - Air Conditioning Compressor Clutch Relay Control Circuit High Voltage - AutoCodes.com — P0647 2015 GMC Sierra Code - Air Conditioning Compressor Clutch Relay Control Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P0647 2015 GMC Sierra?

Faulty Air Conditioning (A/C) Compressor Clutch Relay
Air Conditioning Compressor Clutch Relay harness is open or shorted
Air Conditioning Compressor Clutch Relay circuit poor electrical connection
Faulty Air Conditioning Compressor Clutch
Faulty Engine Control Module (ECM)

How to Fix the DTC P0647 2015 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 P0647 2015 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 P0647 2015 GMC Sierra code?

Need more information on how to fix the P0647 2015 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0647 2015 GMC Sierra 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 P0647 2015 GMC Sierra Code

1. What are the common symptoms of OBDII code P0647 in a 2015 GMC Sierra related to the Air Conditioning Compressor Clutch Relay Control Circuit High Voltage issue?

The common symptoms may include the air conditioning system not working properly, the compressor not engaging, and the AC blowing warm air.

2. What are the potential causes of OBDII code P0647 in a 2015 GMC Sierra indicating a problem with the Air Conditioning Compressor Clutch Relay Control Circuit High Voltage?

Possible causes may include a faulty air conditioning compressor clutch relay, damaged wiring or connectors in the relay circuit, or a malfunctioning PCM (Powertrain Control Module).

3. How can I diagnose the Air Conditioning Compressor Clutch Relay Control Circuit High Voltage problem indicated by OBDII code P0647 in my 2015 GMC Sierra?

You can use a multimeter to check the continuity of the relay, inspect the wiring and connectors for any damage, and test the PCM for proper operation using a diagnostic scanner.

4. What are the repair options for resolving OBDII code P0647 in a 2015 GMC Sierra related to the Air Conditioning Compressor Clutch Relay Control Circuit High Voltage issue?

Repair options may include replacing the faulty air conditioning compressor clutch relay, repairing or replacing damaged wiring or connectors, or reprogramming the PCM if necessary.

5. Can I continue driving my 2015 GMC Sierra with OBDII code P0647 indicating a problem with the Air Conditioning Compressor Clutch Relay Control Circuit High Voltage?

It is not recommended to drive the vehicle with this issue, as it can lead to further damage to the air conditioning system. It is advised to address the problem promptly.

6. How difficult is it to replace the air conditioning compressor clutch relay in a 2015 GMC Sierra to fix OBDII code P0647?

Replacing the relay is a relatively straightforward task that can be done by following the vehicle's service manual or seeking assistance from a professional mechanic.

7. Will resetting the OBDII code P0647 in my 2015 GMC Sierra related to the Air Conditioning Compressor Clutch Relay Control Circuit High Voltage issue solve the problem?

Simply resetting the code may temporarily clear the warning light, but it will not fix the underlying issue causing the code. It is essential to diagnose and address the root cause of the problem.

8. Are there any preventive maintenance tips to avoid encountering OBDII code P0647 in a 2015 GMC Sierra linked to the Air Conditioning Compressor Clutch Relay Control Circuit High Voltage issue?

Regularly inspecting and maintaining the air conditioning system components, such as the relay, wiring, and connectors, can help prevent issues that may trigger this trouble code.

9. Can extreme weather conditions or environmental factors contribute to triggering OBDII code P0647 in a 2015 GMC Sierra related to the Air Conditioning Compressor Clutch Relay Control Circuit High Voltage?

Extreme temperatures, moisture, or exposure to harsh environmental elements can potentially impact the components involved in the air conditioning system, leading to issues like the one indicated by this trouble code.

10. Is it necessary to visit a dealership or specialized auto repair shop to address OBDII code P0647 in a 2015 GMC Sierra associated with the Air Conditioning Compressor Clutch Relay Control Circuit High Voltage issue?

While a dealership or specialized shop may have the expertise and tools to diagnose and fix this problem, a skilled independent mechanic can also effectively address the issue, potentially at a lower cost.