Engine-Codes.com
Engine-Codes – GMC – P0645 2017 GMC Sierra

P0645 2017 GMC Sierra Code - Air Conditioning Compressor Clutch Relay Control Circuit

Quick Answer

The P0645 diagnostic trouble code (DTC) in a 2017 GMC Sierra relates to the Air Conditioning Compressor Clutch Relay Control Circuit. Common causes include Faulty air conditioning compressor clutch relay, Wiring issues in the control circuit, Defective PCM. 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
P0645 2017 GMC Sierra indicates Air Conditioning Compressor Clutch Relay Control Circuit.
Common causes
Common causes include Faulty air conditioning compressor clutch relay, Wiring issues in the control circuit, Defective PCM.
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.
What is this?
Table of contents Created and updated by William Orellana on Sep 16, 2024
💬 Need more help? Ask Auto Expert for instant answers — it's free!
AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play

Code P0645 2017 GMC Sierra Description

The P0645 diagnostic trouble code (DTC) in a 2017 GMC Sierra relates to the Air Conditioning Compressor Clutch Relay Control Circuit. This code indicates that there is a malfunction in the control circuit that operates the air conditioning compressor clutch relay. The air conditioning compressor clutch is responsible for engaging and disengaging the compressor, which is essential for the proper functioning of the vehicle's air conditioning system. When the control circuit malfunctions, it can lead to issues with the air conditioning system, affecting the vehicle's comfort and potentially causing other problems.

OBDII Code P0645 2017 GMC Sierra - Air Conditioning Compressor Clutch Relay Control Circuit
P0645 2017 GMC Sierra Code - Air Conditioning Compressor Clutch Relay Control Circuit

Common Causes of P0645 2017 GMC Sierra

  1. Faulty air conditioning compressor clutch relay.
  2. Wiring issues in the control circuit.
  3. Defective PCM.
  4. Poor electrical connections.
  5. Environmental factors such as moisture or corrosion affecting the circuit.

Symptoms of P0645 2017 GMC Sierra

  1. Lack of cool air coming from the air conditioning system.
  2. Air conditioning system not engaging at all.
  3. Constant engagement of the air conditioning compressor, leading to excessive wear.
  4. Illumination of the check engine light on the dashboard.
  5. Unusual noises coming from the air conditioning system.

How to Fix P0645 2017 GMC Sierra

  1. Begin by diagnosing the specific cause of the issue using a scan tool to read the DTC and pinpoint the exact problem.
  2. Inspect the air conditioning compressor clutch relay and wiring for any visible signs of damage or wear.
  3. Test the electrical connections in the control circuit to ensure they are secure and functioning correctly.
  4. Replace the faulty air conditioning compressor clutch relay if necessary.
  5. Clear the DTC and test the air conditioning system to ensure proper operation.

Cost to Fix P0645 2017 GMC Sierra

The typical repair costs for addressing the P0645 code in a 2017 GMC Sierra can vary depending on the specific cause of the issue. In general, the cost of replacing the air conditioning compressor clutch relay and addressing any wiring or electrical issues can range from $150 to $400, including parts and labor. It is important to note that diagnosis time and labor rates at auto repair shops can vary, so it is advisable to check local rates for a more accurate estimate.

Need more information about the P0645 2017 GMC Sierra code?

Need more information on how to fix the P0645 2017 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0645 2017 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 P0645 2017 GMC Sierra Code

1. What does OBDII code P0645 on a 2017 GMC Sierra indicate?

The P0645 code specifically refers to a fault in the Air Conditioning Compressor Clutch Relay Control Circuit.

2. What are the common symptoms associated with OBDII code P0645 in a 2017 GMC Sierra?

Common symptoms include inoperative air conditioning, the AC compressor not engaging, and potential illumination of the check engine light.

3. What are the possible causes of OBDII code P0645 in a 2017 GMC Sierra?

Potential causes of this code can include a faulty AC compressor clutch relay, damaged wiring or connectors in the circuit, low refrigerant levels, or a malfunctioning AC compressor.

4. How can I diagnose the issue related to OBDII code P0645 in my 2017 GMC Sierra?

To diagnose the problem, you can use a scan tool to check for the specific code, visually inspect the wiring and connectors in the AC compressor clutch relay circuit, and test the relay and compressor clutch for proper functionality.

5. Can I still drive my 2017 GMC Sierra with OBDII code P0645?

It is generally safe to drive the vehicle with this code, but you may experience discomfort due to the lack of air conditioning. It is recommended to address the issue promptly to avoid further damage.

6. How can I repair OBDII code P0645 on a 2017 GMC Sierra?

Repair options may include replacing the faulty AC compressor clutch relay, repairing or replacing damaged wiring or connectors, ensuring proper refrigerant levels, or addressing any issues with the AC compressor itself.

7. Is it possible to reset OBDII code P0645 in a 2017 GMC Sierra without repairs?

While clearing the code with a scan tool may temporarily turn off the check engine light, the underlying issue causing the code will persist until properly addressed.

8. Are there any preventive measures to avoid OBDII code P0645 in a 2017 GMC Sierra?

Regular maintenance of the air conditioning system, including checking refrigerant levels and ensuring proper relay function, can help prevent issues leading to this OBDII code.

9. Can a DIY enthusiast fix OBDII code P0645 in a 2017 GMC Sierra?

Depending on the individual's experience and tools available, some DIY enthusiasts may be able to diagnose and repair this issue, especially if it involves basic tasks like replacing a relay or checking wiring.

10. How much can I expect to pay for professional repair of OBDII code P0645 on a 2017 GMC Sierra?

The cost of professional repair can vary based on the specific cause of the issue, but it may range from around $100 for a simple relay replacement to several hundred dollars for more complex repairs involving the compressor or wiring.

Discuss the causes and fixes for P0645 2017 GMC Sierra OBDII Code

Submit a New Comment

Code P0645 2017 GMC Sierra comments

No comments found for this page.